United States
Environmental Protection
Agency
Office of Mobile Source Air Pollution Control
Emission Control Technology Division
2565 Plymouth Road
Ann Arbor, Michigan 48105
EPA 460/3-84-007
August 1985
Air
Lead-Poisoned Catalyst
Evaluation
-------
EPA 460/3-84-007
Lead-Poisoned Catalyst Evaluation
by
E. Robert Fanick
and
Melvin N. Ingalls
Southwest Research Institute
6220 Culebra Road
San Antonio, Texas 78284
Contract No. 68-03-3162
Work Assignment 17
EPA Project Officer: Craig A. Harvey
EPA Branch Technical Representative: R. Bruce Michael
Prepared for
ENVIRONMENTAL PROTECTION AGENCY
Office of Mobile Source Air Pollution Control
Emission Control Technology Division
2565 Plymouth Road
Ann Arbor, Michigan 48105
August 1985
-------
This report is issued by the Environmental Protection Agency to report
technical data of interest to a limited number of readers. Copies are available
free of charge to Federal employees, current contractors and grantees, and
nonprofit organizations - in limited quantities - from the Library Services
Office, Environmental Protection Agency, 2565 Plymouth Road, Ann Arbor,
Michigan 4.8105.
This report was furnished to the Environmental Protection Agency by Southwest
Research Institute, 6220 Culebra Road, San Antonio, Texas, in fulfillment of
Work Assignment No. 17 of Contract No. 68-03-3162. The contents of this
report are reproduced herein as received from Southwest Research Institute.
The opinions, findings, and conclusions expressed are those of the author and
not necessarily those of the Environmental Protection Agency. Mention of
Company or product names is not to be considered as an endorsement by the
Environmental Protection Agency.
Publication No. EPA-460/3-84-007
ii
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FOREWORD
This project was conducted for the U.S. Environmental Protection Agency
by the Department of Emissions Research at Southwest Research Institute
(SwRI). It was begun in February 1984, and completed in 3une 198^. The
project was conducted under Work Assignment 17 of Contract 68-03-3162, and
was identified within Southwest Research Institute as Project 03-7338-017.
Mr. Robert J. Garbe of the Emission Control Technology Division, Office
of Mobile Source Air Pollution Control, Environmental Protection Agency, Ann
Arbor, Michigan, served as EPA Project Officer for most of the project. Mr.
Craig Harvey of the same EPA Office served as Project Officer for the last
stages of the project. Mr. R. Bruce Michael, Emission Control Technology
Division, Office of Mobile Source Air Pollution Control, EPA, Ann Arbor,
Michigan was the Branch Technical Representative for the project. Mr. Charles
T. Hare, Manager, Advanced Technology, Department of Emissions Research,
Southwest Research Institute, served as the Project Manager. E. Robert
Fanick, Research Scientist, served as Project Leader and Principal investigator.
Other key personnel at SwRI involved in the project were Ms. Karen B. Kohl,
who supervised the x-ray fluorescence analysis, Mr. James G. Barbee, who
supervised the scanning electron microscope, and Mr. Edward H. Ruescher, who
supervised the whole catalyst x-ray analysis. The support personnel at SwRI
involved in this program included Dennis M. Lovell, A. Joyce Winfield, Pam
Nickoloff, James G. Herrera and O.C. Skiles.
ill
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TABLE OF CONTENTS
Page
FOREWORD iii
LIST OF FIGURES vii
LIST OF TABLES ix
SUMMARY xi
I. INTRODUCTION 1
II. BACKGROUND 3
III. WHOLE CONVERTER RADIOGRAPH 9
IV. VISUAL INSPECTION AND WEIGHING 13
V. SURFACE AREA BY BET ANALYSIS 15
VI. ELEMENTAL ANALYSIS BY X-RAY FLUORESCENCE 17
VII. SCANNING ELECTRON MICROSCOPE 27
VIII. ANALYSIS OF TEST RESULTS 29
REFERENCES
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LIST OF FIGURES
Figure Page
1 Initial and Finai FTP Results from Misfueled Vehicles
(hydrocarbons) 6
2 Initial and Final FTP Results from Misfueled Vehicles
(carbon monoxide) 7
3 Initial and Final FTP Results from Misfueled vehicles
(NOX) 8
4 Location of Densitometer Readings 10
5 Plot of Densitometer Values Versus Lead Concentrations
Per Biscuit 12
6 Specific Surface Area of Misfueled Converters 16
7 Weight Percent Sulfur 19
8 Weight Percent Lead 20
9 Weight Percent Nickel 21
10 Weight Percent Platinum 22
11 Weight Percent Palladium 23
12 Typical Example of Catalyst Surface from Misfueled
Vehicle (GM-Vehicle 307) 27
13 Percent Increase in HC Emissions 36
1^ Percent Change in CO Emissions 37
15 Percent Change in NOX Emissions 38
16 Percent of Fuel Lead Retained in Catalyst 39
vii
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LIST OF TABLES
Table
1 Selected Converters from EPA Misfueling
Programs 3
2 Effect of Misfueling on Exhaust Emissions 5
3 Densitometer Values from Whole Converter Radiographs 11
4 Converter Weights 13
5 Catalyst Specific Surface Area 15
6 Elemental Analysis of Noble Metals and Poisons in
Intentionally Leaded Catalysts 18
7 Mass of Metals and Poisons in Intentionally
Leaded Converters 24
8 Comparison of Noble Metals by Manufacturers 25
9 Correlation Among Elements Found on Catalysts 30
10 Percent Change in Emissions for Eight Vehicles
Operated on Leaded Fuel 32
11 Average XRF and BET Analysis Results for Catalyst
Systems on Eight Cars 32
12 Correlation Between Catalyst Elements and Emission
Changes 33
13 Summary Statistics for Emission Changes for Eight
Cars Operated on Leaded Fuel 34
ix
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SUMMARY
The purpose of this project was to provide the Environmental Protection
Agency (EPA) with information which could be used in conjunction with EPA
emission test data to evaluate the relationship between catalyst condition and
emission levels. The catalysts evaluated in this program had been intentionally
poisoned with known amounts of leaded gasoline. The catalysts represent four
different vehicle manufacturers from eight different vehicles with three-way
catalyst technology.
Ten catalysts were examined using several physical and chemical
procedures for poison accumulation, overheating, plugging, thermal
deterioration and noble metal loss. The analysis of each catalyst consists of
external visual inspection, whole converter radiographs, internal visual
inspection, weighing of catalysts, BET surface area analysis, elemental analysis
for noble metals and poisons, and scanning electron microscope examination of
the surface.
Whole converter radiographs (x-rays) of the converters were performed to
check for cracks, voids, meltdowns, and lead distribution prior to disassembly of
the converter.
The converters showed an interesting correlation between the
concentration of lead (measured by x-ray fluorescence) and the film negative
opacity using the whole converter radiographs. As the lead concentration in
each biscuit increased, the opacity of the radiographs decrease.
During disassembly, visual inspections were performed for evidence of
physical damage, plugging, overheating, and the evaluation of discoloration and
deposit patterns. Samples of the catalytic material were taken for BET surface
analysis, elemental analysis by x-ray fluorescence, and examination with a
scanning electron microscope. The results from all of the analyses for each
catalyst are presented for comparison purposes.
The elements quantified by x-ray fluorescence were phosphorus (P), sulfur
(S), calcium (Ca), manganese (Mn), zinc (Zn), lead (Pb), platinum (Pt), palladium
(Pd), nickel (Ni), and rhodium (Rh). In general, the Ni and Pb concentrations
were higher on the first biscuit and S concentration was higher on the second
biscuit. Most of the biscuits contained both Pt and Pd. Cerium (Ce), titanium
(Ti) and iron (Fe) were found in many of the converters.
The catalyst surface of the upstream biscuits when observed through a
scanning electron microscope had the appearance of very fine grains spread
evenly over the surfact. The downstream biscuits had the appearance of dried
cracked mud. All of the micrographs were taken at the magnification of X500.
A short statistical analysis was performed to examine the correlation
between the analytical results and/or the emission levels. The best linear
correlations, in terms of the analytical results only, were between Zn and P, Zn
and Ca, and Ni and S. the Ni/5 correlation was an increase relation (i.e. an
increase in S results in a decrease of Ni and vice versa). Another linear
xi
-------
correlation was conducted for the average weight percent of the elements in
each container, the percent change in the emissions, and the fuel lead put
through the vehicle. The fuel lead correlated with P and Zn, and the
hydrocarbons and oxides of nitrogen correlated with S. A moderate correlation
existed between CO and Pb. It is not possible to draw conclusions regarding any
relationship between the lead retained in the converters and the increase in
vehicle emission levels with the limited catalyst sample examined. The
evaluation of additional catalysts would be necessary to determine any
relationship between these variables.
xii
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I. INTRODUCTION
Since 1975, exhaust gas catalytic converter systems have been the
principal means of automotive pollution control. The catalytic activity of the
converter can be degraded by engine and emission control system malfunctions
and by the use of leaded fuel. This project examined a number of catalytic
converters in an effort to describe the physical condition of the catalytic
material after exposure to known amounts of leaded gasoline.
This examination included radiographs of whole monolithic catalysts for
cracks, voids, and meltdowns; visual inspection of the converters as they were
disassembled; and weighing of the catalytic material. Several physical and
chemical analytical procedures were performed to further define the condition
of the catalyst. These procedures included BET surface area, elemental
analysis by x-ray fluorescence, and surface examination using a scanning
electron microscope.
The purpose of this project was to provide the EPA with information on
the condition of each catalyst. This information included examination for
poison accumulation, overheating, plugging, thermal deterioration, and noble
metal loss. The EPA will use this information, together with the results from
emissions tests on the vehicles from which these converters were taken, in an
effort to correlate emission test results with catalyst condition and lead
loading. A description of each of the procedures is included in Appendix A.
For the purpose of identifying the converters analyzed in the program,
each converter will be designated by the three digit EPA vehicle number on the
vehicle from which the converter was removed. In the event of a dual
converter vehicle, the converters were also identified -1 and -2 after the three
digit vehicle number. No means were available to determine where the
converter was located on the vehicle (i.e. right bank or left bank of the engine);
therefore, these numbers are arbitrary. The term "biscuit" will be used to refer
to each individual piece of monolithic catalyst material in a converter. In the
case of two "biscuit" converters, the upstream biscuit was labeled "A" and the
downstream biscuit was labeled "B".
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IL BACKGROUND
The converters were obtained from EPA and were collected from four
different misfueling programs. Three of those programs were conducted by an
EPA contractor, Automotive Test Laboratory (ATL) in Ohio, and one was
conducted "in-house".(D Each program utilized a different method of
misfueling the vehicle. Table 1 identifies the converters selected for this
program and the source and type of misfueling. In all cases, the converters
were removed for future analysis and new converters were placed on the
vehicles.
TABLE 1. SELECTED CONVERTERS FROM EPA MISFUELING PROGRAMS
Vehicle
002
004
304*
307
309
310a
312
9M
Program
ATL #1
ATL #1
ATL #5
ATL //5
ATL #6
ATL # 5
ATL #6
In-House
MYR
81
81
82
83
83
83
82
83
MFR
Ford
VW
Ford
GM
Chrysler
Ford
GM
GM
Eng. Fam
1.6AP
BVW1.7V6
FF537F
CFM5.0V2
HDF8
DIG3.8V2
NDA4
DCR2.2V2
HAC3
DFM5.0V5
HLF8
CIG5.0V5
NBM2
DIG2.8V2
NNA9
Fuel
Lead
Grams
88.9
93.0
201.5
105.2
56.2
76.7
66.2
60.0
Approximate
# of tankfuls
of leaded fuel
10
10
12
12
4
4
4
4
aDual converters
*Numbers in parentheses refer to references at the end of this report.
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Test Programs
In the first program (ATL #1), the effect on emissions from misfueling
vehicles with 10 tankfuls of leaded fuel was investigated. Each vehicle met
several criteria:
1. 1981 with 25,000 miles or 1982 with 15,000 miles
2. Less than 0.05 g per gallon lead used previously
3. Tailpipe checked for lead-negative
4. Vehicles require only minor adjustments to manufacture
specification
5. No vehicle with emission levels more than 50% above FTP
certification standards
6. All mileage accumulated during the program on a track
All emission tests were performed with Indolene unleaded gasoline and the
emission tests were conducted after every two tanks. The leaded fuel for all
vehicles was to be from one source and have between 1.09 and 0.98 g lead per
gallon. Two converters were obtained from this program (Ford-002 and VW-
004).
The second program (ATL //5) involved misfueling during approximately
one out of every two tanks. The same criteria applied to this program with
these changes:
1. 1981-1983 model years
2. Closed-loop, three-way catalyst (with or without additional
oxidation catalyst) system
3. ^000 odometer miles or greater
k. No two engine families alike
5. All mileage accumulation performed during the program in normal
driving on public roads
6. Unleaded fuel for mileage accumulation from commercial sources.
Two converters were obtained from this program (Ford-30* and GM-307).
The third program (ATL #6) involved criteria similar to ATL //5 except
that the vehicles were misfueled approximately one out of every four tanks and
the mileage accumulation consisted of a one-hour road route at an average
speed of 32 mph. All unleaded fuel purchases were to be made at a designated
service station on the road route where the lead content of the station fuel tank
was checked at least once each week. Three converters were obtained from
this program (Chrysler-309, Ford-310, and GM-312).
-------
The fourth program was an EPA in-house intermittent misfueling
program. Criteria similar to the previous programs were used. The major
difference involved the casual or intermittent misfueling of the vehicle. Using
the composite city/highway fuel economy, the approximate mileage per tankful
was calculated. The vehicle was then misfueled after more than three tanks of
unleaded fuel were used on the basis of the mileage calculation. One converter
was provided for analysis from this program (GM-941).
Emission Results
Results of emission tests conducted during the four programs were
provided to SwRI by EPA. The initial emission test was conducted on each
vehicle before misfueling, and the final emission test was the last test after all
of the misfueling and mileage accumulation had been completed. Table 2 shows
the results of these tests on each vehicle. All emission tests in this table are
from a cold-start Federal Test Procedure (CFTP) using unleaded Indolene
gasoline. The emission trends are presented in Figures 1 through 3. In general,
all of the final emissions were higher than the initial values with exception of
the NOX for vehicles 304 and 309.
TABLE 2. EFFECT OF MISFUELING ON EXHAUST EMISSIONS
Total
Fuel CFTP Emissions
Vehicle Grams HC CO NOY
002 Initial 0.57 11.80 0.59
88.9 2.14 39.60 0.82
004 Initial 0.33 2.01 0.98
93.0 1.40 2.24 1.98
304 Initial 0.75 11.44 0.84
201.5 3.64 30.32 0.82
307 Initial 0.22 1.33 0.79
105.2 1.41 2.62 1.33
309 Initial 0.40 4.12 1.00
56.2 1.29 5.92 0.83
310 Initial 0.37 5.40 0.68
76.7 1.34 6.33 1.15
312 Initial 0.40 4.84 0.54
66.5 0.71 5.34 0.79
941 Initial 0.17 1.66 0.92
60.0 0.58 3.25 1.00
-------
4.0 -,
Initial
Final
CO
g
m
u
3.0 -
2.0 -
1.0 -
002
004
304
310
312
307 309
Vehicle Number
Figure 1. Initial and final FTP results from misfueled vehicles (hydrocarbons)
941
-------
Initial
Final
u
002
004
304
307
Vehicle Number
309
310
312
Figure 2. Initial and final FTP results from misfueled vehicles (carbon monoxide)
-------
Initial
Final
002
004
Figure 3.
304
307 309
Vehicle Number
310
312
941
Initial and final FTP results from misfueled vehicles (HOX)
-------
IIL WHOLE CONVERTER RADIOGRAPH
A whole converter radiograph was obtained for each converter. This
served two major purposes: to determine internal structural damage,
overheating, etc.; and to assist in opening the container without damaging the
biscuits. A description of the procedures used in conducting the analysis is
included in Appendix A, and the radiographs of each converter when lying flat
are shown in Appendix B.
In general, the radiographs do not provide a significant amount of
quantitative data. Cracks were observed in both biscuits of 307 and 312. A
large section of the front face of 312 was shown to be missing. This piece did
not appear to be lodged in another part of the container. A dark band was also
observed on the upstream edge of A biscuit for each converter. This is
presumably from a high concentration of lead deposition. Converters 002 and
309 also show a dark band on the upstream side of the B biscuit.
In an attempt to correlate these light and dark regions, a densitometer
was employed with the negatives. Eight locations each on the upstream and
downstream side of each biscuit were examined with the densitometer (See
Figure 4). On the photographic negative, a lower number indicates more lead
(i.e., less film exposure to the x-rays or more x-rays absorbed by lead). This
translates to a dark region in the positives shown in Appendix B. The results
from the densitometer are presented in Table 3. The film density is defined as
the logarithm of the opacity or the logarithm of the reciprocal of the
transmittance of the light through the film. Transmittance is defined as:
Transmittance = Transmitted light
Incident light
Opacity is defined as:
Opacity = 1_
Transmittance
and
Density = log Opacity = log I
Transmittance
The density of the image on the negative depends on the length of the
exposure, thickness of the container, energy of the x-rays, and the angle of the
converter with respect to the film. Figure 5 was plotted from the average
densitometer values taken from the upstream portion of each biscuit. In
general, the graph illustrates the correlation of the lighter areas from the
radiographs with the mass of lead in each whole biscuit obtained from the x-ray
fluorescence (i.e., the highest concentration of the lead deposits is located on
the upstream portion of each biscuit). The one converter that did not fit the
trend was the VW converter 004 (identified in Figure 5). This converter was
irradiated for a longer time because it had a much thicker container than the
other converters. As a result of the longer irradiation time and the thicker
container, the actual densitometer values for this converter will be different.
If the values are then normalized to account for these differences a linear
relationship between the film density and lead concentration should result.
-------
FLOW
!•&•!*&
Biscuit
A
Biscuit
B
Figure 4. Locations of densitometer readings
10
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TABLE 3. DENSITOMETER VALUES FROM WHOLE CONVERTER RADIOGRAPHS
Catalyst
No.
002
00*
301*- 1
304-2
307
309
310-1
310-2
312
9*1
Biscuit
No.
A-Front
A -Back
B-Front
B-Back
Front
Middle
Back
A-Front
A-Back
B-Front
B-Back
A-Front
A-Back
B-Front
B-Back
A-Front
A-Back
B-Front
B-Back
A-Front
A-Back
B-Front
B-Back
A-Front
A-Back
B-Front
B-Back
A-Front
A-Back
B-Front
B-Back
A-Front
A-Back
B-Front
B-Back
A-Front
A-Back
B-Front
B-Back
1
O.SO
0.93
1.07
1.05
1.14
1.02
1.05
0.93
1.03
0.90
1.10
0.70
1.21
1.23
1.32
1.02
1.01
0.9*
1.09
1.01
0.88
0.80
1.02
1.00
1.21
1.2*
1.16
0.9*
1.22
1.22
1.53
1.02
1.11
1.16
1.12
0.89
1.00
l.ll
1.0*
2
0.50
0.83
0.69
1.19
0.78
0.81
0.90
0.61
1.21
1.01
1.38
0.52
1.**
1.35
1.30
0.82
1.19
1.07
1.14
1.0*
0.98
0.69
1.06
0.90
1.25
1.37
1.21
0.92
1.28
l.*0
1.68
0.97
1.36
1.50
l.*8
0.69
1.22
1.2*
1.38
Film
3
O.*0
0.83
0.59
1.10
0.59
0.67
0.82
0.51
1.2*
1.39
1.61
0.50
1.39
1.23
1.25
0.6S
1.1*
1.0*
1.16
0.91
0.89
0.63
0.95
0.81
1.1*
l.*9
1.11
0.82
l.*8
1.30
1.71
0.87
l.*2
1.50
1.52
0.57
1.18
1.38
1.35
Density at Position
*
0.36
0.75
0.63
0.92
0.*9
0.63
0.81
0.50
1.12
1.25
1.39
0.52
1.50
1.25
1.27
0.61
1.16
1.03
1.09
0.89
0.97
0.58
0.93
0.80
1.09
1.52
1.10
0.78
1.27
l.*l
1.88
0.78
1.35
l.*7
1.57
0.53
1.05
l.*0
1.31
5
0.38
0.61
0.63
0.8*
0.56
0.57
0.75
0.*7
1.12
1.39
1.35
0.61
1.46
1.27
1.32
0.67
1.10
1.25
1.47
0.83
0.96
0.60
0.91
0.77
1.05
1.48
1.27
0.76
1.38
1.41
1.8*
0.8*
1.40
1.63
1.67
0.50
1.11
1.36
1.19
6
0.50
0.67
0.65
0.96
1.03
1.17
1.28
0.45
1.13
1.25
1.32
0.56
1.48
1.19
1.39
0.66
1.17
1.14
1.11
0.85
0.93
0.61
0.97
0.89
1.10
1.29
1.22
0.82
1.42
1.35
1.61
1.03
1.4*
1.44
1.41
0.56
1.20
1.28
1.20
7
0.72
0.93
0.68
1.09
—
0.47
1.27
1.35
1.27
0.66
1.39
1.01
1.32
0.73
1.1*
1.03
1.19
0.88
0.92
0.73
1.06
0.87
1.13
1.40
1.15
0.89
1.32
1.35
1.70
0.99
1.33
1.47
1.35
0.61
1.18
1.38
1.33
8
0.72
0.98
0.99
1.12
—
0.59
1.09
1.15
1.09
0.83
1.17
1.10
1.09
0.86
1.06
0.90
1.02
0.96
0.82
0.90
1.16
0.92
1.02
1.40
1.21
1.02
1.17
1.33
1.57
1.22
1.19
1.2*
1.20
0.70
1.06
1.23
1.26
Avp.
0.55
0.82
0.74
1.03
0.77
0.81
0.94
0.57
1.31
1.22
1.31
0.61
1.38
1.20
1.27
0.76
1.12
1.05
1.16
0.92
0.92
0.69
1.01
0.87
1.12
1.40
1.18
0.87
1.32
1.35
1.69
0.97
1.33
1.43
1.42
0.63
1.13
1.30
1.26
Pb. g
12.762
8.351
21.448
11.243
5.905
13.09*
5.998
15.201
10.665
7.552
11.071
S.*04
4.519
8.025
3.084
10.807
4.934
17.201
3.848
11
-------
30
25
20
C
O
o
fi
o
o
T)
(fl
ID
10
VW Converter
LEGEND
A Biscuit
B Biscuit
I
I
0.2
0.4
0.6 0.8 1.0
Densitometer Values
1.2
1.4
1.6
Figure 5. Plot of densitometer values versus lead concentration per biscuit
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IV. VISUAL INSPECTION AND WEIGHING
Each converter was photographed both externally and internally. The
photographs of all the converters are shown in Appendix C. In general, the
external and internal views for each manufacturer's converters are similar.
The weights of the converters were determined in various stages. All
converters were shipped to SwRI with the mounting brackets and heat shields
intact except for 004, 310-1, and 310-2. Each converter was weighed with and
without the mounting brackets and heat shields. Once the containers were
opened, the individual biscuits were reweighed. All these weights are presented
in Table 4.
TABLE 4. CONVERTER WEIGHTS
Whole Converter Biscuits
Converter
Number
002
004
304-1
304-2
307
309
310-1
310-2
312
941
With Mounting
Brackets, Ib
10.76
11.68
11.88
11.95
10.51
11.95
11.75
Without Mounting
Brackets, Ib
7.18
5.80
8.97
8.95
10.93
9.86
8.85
8.95
10.83
10.67
Upstream-A,
R
402.6
936.6
493.1
471.0
894.2
1110.6
390.9
393.4
831.3
945.1
Downstream-B,
R
372.8
~
444.0
451.0
725.5
477.2
451.9
411.2
715.1
726.1
In general, the weights for each biscuit from individual manufacturers are
very similar. Both biscuits in Ford converters weigh approximately 400 g. In
the case of GM converters, the upstream biscuit is more than 100 g heavier
than the downstream biscuit. With Chrysler converters, the upstream biscuit is
more than twice as heavy. The VW converter was the only single-biscuit
converter in this study. No comparisons were made in the converter weights
between clean, unused converters and the intentionally leaded converters from
this program.
Three converters showed internal structure damage to the substrate
material upon opening the container. These converters were 307, 310-2 and
13
-------
312. Two of the three GM converters (307 and 312) were cracked perpendicular
to the flow of the exhaust. Each biscuit in each container was cracked almost
exactly in half. These converters were either damaged during the
manufacturing or possibly overheated during use. In addition, a large section
from the front face of the upstream biscuit was missing from 312. The damage
to 310-2 consisted of a section missing from the edge of the front face of the B
biscuit. No traces of the pieces were found for either of these converters, so it
was presumed that the pieces were missing at the time the converters were
installed by the vehicle manufacturer or lost upon removal from the vehicle.
All of the other converters were intact and showed no signs of overheating or
internal damage. The internal examination of each converter verified the
observation from the whole catalyst radiographs. Upon close inspection, all of
the converters consisted of square cells, with the exception of the Chrysler
converter, which had triangular cells. In general the upstream face of each
biscuit was darker in color (dark gray to black) than the downstream face of the
same biscuit. Only 002 and 941 showed any appreciable amount of plugging of
the upstream biscuit. Converters 002 and 004 were the lightest in color. These
two converters were from the program which misfueled vehicles continuously,
ATL #1.
14
-------
V. SURFACE AREA BY BET ANALYSIS
The specific surface area of each biscuit was determined by
Micromeritics Instrument Corporation using the BET method. A description of
the sampling and analysis procedure is presented in Appendix A. The computer
printouts and raw data provided by Micromeritics are presented in Appendix C.
In general, the specific surface areas for converters 002 and 00* were less
than the other converters with the exception of 309, 312, and the B biscuit of
304-2. Converters 002 and 00* were misfueled with 10 tankfuls of leaded fuel
and did not have a chance to "burn off" the deposits with any unleaded fuel
between misfuelings. Converter 312 was one of the converters that had a
number of structural fractures perpendicular to the flow of the exhaust. Each
biscuit was cracked to tow almost equal pieces. The cracks, combined with the
low specific surface area, may indicate that this catalyst had been overheated.
All of the other converters had a specific surface area greater than 10 m^/g.
The overheating of the converter could also be verified by a technique call x-
ray diffraction. This technique determines the change in alummina crystal
structure caused by overheating. In many uses the overheating of the catalyst
lowers the surface area of a catalyst.
The specific surface area data for each converter are presented in Table 5
and illustrated in Figure 6. Two of the three GM converters had the highest
surface area (307 and 9*1) but the lowest surface area was also a GM (312). No
data were available to draw conclusions about the change in surface area due to
lead deposition in comparison with clean, unused converters. The effective
surface area for gamma alumina is typically on the order of 100-200 m2/g.(2)
The total surface area of a biscuit depends on the volume (size) of the biscuit,
the cell size of the biscuit and the thickness of the wash coat.
TABLE 5. CATALYST SPECIFIC SURFACE AREA
Biscuit Surface Area
Number Specific, m^/g Total, m^
002-A 9.6 3,856
002-B *.* 1,6*0
00* 6,0 5,620
30*-1-A 10.3 5,079
30*-1-B 13.6 6,038
30*-2-A 12.7 5,982
30*-2-B *.* 1,98*
307-A 22.9 20,*77
307-B 19.2 13,930
309-A 7.7 8,552
309-B 5.* 2,577
310-1-A 18.2 7,11*
310-1-B 17.5 7,908
310-2-A 16.1 6,33*
310-2-B 16.1 6,620
312-A 1.5 1,2*2
312-B 5.5 3,933
9*1-A 18.* 17,390
9*1-B 2*.l 17,*99
15
-------
25.0 -I
20.0
CN
E
0)
u
15.0 ~
.3 io-o
O
0)
5.0 ~
002
A Biscuit
B Biscuit
004
304-1 304-2 307 309
Converter Number
310-1
310-2
312
941
Figure 6. Specific surface areas of misfueled converters
-------
VI. ELEMENTAL ANALYSIS BY X-RAY FLUORESCENCE
One half of each biscuit was ground into a homogeneous sample for
analysis by x-ray fluorescence. The procedures used to take and analyze the
samples are given in Appendix A. The elements of concern included phosphorus
(P), sulfur (S), calcium (Ca), manganese (Mn), zinc (Zn), lead (Pb), platinum (Pt),
palladium (Pd), and rhodium (Rh). Nickel (Ni) was added to the list when high
concentrations were observed. The elements P, S, Ca, Mn, Zn and Pb are
present in the converters as poisons and contaminants. These elements are
derived from engine wear, dirt deposits, oil, fuel, etc. The noble metals (Pt,
Pd, and Rh) are the catalyst metals which perform the function of "cleaning up"
the exhaust. Nickel is also a metal which exhances the catalytic activity. One
example which has been observed is the decrease in ammonia formation due to
the addition of nickel to the cataiyst.(3,4) Aluminum and silicon are major
constituents of the substrate but were not quantitatively determined.
The weight percent of each element was determined by the analytical
procedure. The results of the analyses are presented in Table 6. The levels for
Mn and Rh in the samples were below the detection limits of the procedure.
Figures 7 through 11 illustrate the weight percent values for S, Pb, Ni, Pt, and
Pd. In general, the S concentration was higher on the second biscuit, while the
Ni and Pb concentrations were greater on the first. The exceptions included
the Chrysler converter (309), which had a higher weight percent of Pb on the
second biscuit, and converter 941, which had a higher weight percent S on the
first biscuit. Platinum and palladium were found in all of the biscuits except
the Chrysler (309), which had only Pt in biscuit A and only Pd in biscuit B. The
Chrysler converter (309) and the VW converter (OOf) did not contain any Ni.
The weight of each element in the biscuit can be determined by multiplying the
weight percent by the weight of each biscuit and dividing by 100. These values
are presented in Table 7, which shows the weight of each element in each
individual biscuit.
Table 8 shows a comparison of the noble metals and Ni by the vehicle
makes. Each manufacturer used about the same amount of nickel in the various
catalysts, but the Pt/Pd/Rh ratios are different for each vehicle.^' This
difference is probably related to the engine size and type of emission control
for each particular vehicle. The ratios of Pt to Pd in the misfueled converters
were very much different from those reported by the manufacturer. The reason
for this difference is not known. The minimum detection limit for Rh is 0.01
weight percent. Since Rh is added to converters in concentrations at or below
the detection limit, it becomes difficult to determine the sample
concentrations. The presence of large amounts of Pb attenuates the f luoresced
x-rays which also interferes with the detection of Rh.
17
-------
TABLE 6. ELEMENTAL ANALYSIS OF NOBLE METALS AND POISONS IN
INTENTIONALLY LEADED CATALYSTS
Biscuit
Number
002-A
002-B
004
304-1-A
304-1-B
304-2-A
304-2-B
307-A
307-B
309-A
309-B
310-1-A
310-1-B
310-2-A
310-2-B
3 12- A
312-B
941-A
941-B
detection
limit
Elements, wt. %
P
0.07
#
0.22
0.18
0.04
0.28
trace
*
*
*
*
0.05
*
trace
*
*
trace
*
*
0.03
S
0.24
1.81
1.46
0.82
1.14
0.65
1.13
1.00
1.55
0.79
1.22
0.82
1.36
0.86
1.05
0.50
0.82
1.19
0.85
0.03
Ca
0.01
0.01
0.03
0.02
0.02
0.02
0.02
*
trace
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.01
*
trace
0.007
Mn
*a
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
0.005
Ni
1.84
0.08
*
2.00
0.10
2.10
0.10
1.80
trace
*
trace
2.41
0.31
2.22
0.26
1.88
0.03
1.45
*
0.01
Zn
traceb
*
0.03
0.02
trace
0.03
trace
*
*
*
*
trace
*
trace
*
trace
trace
*
*
0.01
Pb
3.17
2.24
2.29
2.28
1.33
2.78
1.33
1.70
1.47
0.68
2.32
2.15
1.00
2.04
0.75
1.30
0.69
1.82
0.53
0.01
Pt
0.08
0.14
0.15
0.16
0.15
0.14
0.13
0.14
0.18
0.15
*
0.39
0.17
0.34
0.15
trace
0.30
0.10
0.18
0.02
Pd
0.04
0.19
0.07
trace
0.28
trace
0.24
0.09
0.13
*
0.64
0.28
0.08
0.33
0.20
0.20
0.20
0.08
0.24
0.02
Rh
*
*
*
*
*
*
*
*
*
*
*
#
*
*
*
*
*
*
*
0.01
a*Element concentration below detection limit
bElement concentration at detection limit
18
-------
A biscuit
B biscuit
C
OJ
U
0.5-
002
I
004
304-1 304.2 307
Converter Number
309
310-1
310-2
312
941
Figure 7. Weight percent sulfur
-------
3.5 -I
A Biscuit
B Biscuit
D
002
304-1
304-2 307 309
Converter Number
310-1
310-2
312
941
Figure 8. Weight percent lead
-------
A biscuit
B biscuit
2.5
2.0
0)
,x
c
flj
u
^
OJ
a
•H
0)
002
004
304-]
304-2 307
Converter Number
310-1
310-2
312
941
Figure 9. Weight percent nickel
-------
A biscuit
B biscuit
0.4 -.
0.3 -
NJ
N>
R 0.2 -
ft
0.1 -
002
004
304-1 304-2 307 309
Converter Number
310-1
310-1
941
Figure 10. Weight percent platinum
-------
0.7-1
0.6 ~
A Biscuit
B Biscuit
0.5
N3 Cn
CO -H
002
004 304-1 304-2
307 309
310-1 310-2
312
941
Converter Number
Figure 11. Weight percent palladium
-------
TABLE 7. MASS IN GRAMS OF METALS AND POISONS IN INTENTIONALLY LEADED CONVERTERS
NJ
ONVERTER
002
004
304-1
304-2
307
309
310-1
310-2
312
941
i ID
A
R
A
A
B
A
P
A
R
A
R
A
B
A
B
A
B
A
R
P
.282
0.000
2.061
.888
.178
1.319
.135*
0.000
0.000
0.000
0.000
.195
0.000
.118*
0.000
0.000
.215*
0.000
0.000
S
.966
6.748
13.674
4.043
5.062
3.062
5.096
8.942
1 1.245
8.774
5.822
3.205
6. 146
3.383
4.318
4.157
5.864
11.247
6.172
CA
.040
.037
.281
.099
.089
.094
.090
0.000
.051*
.222
.095
.078
.090
.079
.082
.166
.072
0.000
.051*
Nl
7.408
.298
0.000
9.862
.444
9.891
.451
16.096
.073*
0.000
.048*
9.421
1.401
8.733
1 .069
15.628
.215
13.704
0.000
ZN
.040*
0.000
.281
.099
.044*
.141
.045*
0.000
0.000
0.000
0.000
.039*
0.000
.039*
0.000
.083*
.072*
0.000
0.000
PB
12.762
8.351
21 .448
11 .243
5.905
13.094
5.998
15.201
10.665
7.552
1 1 .071
8.404
4.519
8.025
3.084
10.807
4.934
17.201
3.848
PT
.322
.522
1.405
.789
.666
.659
.586
1.252
1.306
1 .666
0.000
1.525
.768
1.338
.617
.166
2.145
.945
1.307
PD
.161
.708
.656
.099*
1.243
.094*
1.082
.805
.943
0.000
3.054
1.095
.362
1.298
.822
1.663
1.430
.756
1.743
* TRACE QUANTITY CALCULATED FROM MINIMUM DETECTION LIMIT
-------
TABLE 8. COMPARISON OF NOBLE METALS BY MANUFACTURER
Concentration, g/biscuit Manufacturers
Noble Metals* Noble Metal Ratios
Converter Biscuit Make Ni Pt Pd Pt Pd Rh
002 Ford 7.41 0.32 0.16 5 1
0.30 0.52 0.71 5 2
304-1 Ford 9.86 0.79 0.10 5 1
0.44 0.67 1.24 3 2
304-2 Ford 9.89 0.66 0.09 5 1
0.45 0.59 1.08 3 2
310-1 Ford 9.42 1.53 1.10 12.2 1
1.40 0.77 0.36 3 2
310-2 8.73 1.34 1.30 12.2 1
1.07 0.62 0.82 3 2
307 GM 16.10 1.25 0.81 5 2 1
0.07 1.31 0.94 7 1
312 GM 15.63 0.17 1.66 3 3 1
0.22 2.15 1.43 8 1
941 GM 13.70 0.95 0.76 5 2 1
0.00 1.31 1.74 5 2
309 Chrysler 0.00 1.67 0.00 10 1
0.05 0.00 3.05 Pdonly
004 VW 0.00 1.41 0.66 5 1
*Rh concentration below the detection limit for the analytical procedure
Several other elements were determined qualitatively. Cerium (Ce),
titanium (Ti), and iron (Fe) were found in all of the converters. The exceptions
to this were the B biscuits from the GM converters (307, 312, and 941), which
did not contain Ce, and the B biscuit of the Chrysler converter (309), which did
not contain Ce or Ti. Titanium was probably present in the converters as a
whitening agent (an agent to enhance the aesthetic appearance of the ceramic
substrate)'^/or as an impurity of the cordierite substrate, and Ce was added to
inhibit the conversion of gamma-alumina (higher surface area) to alpha-alumina
(lower surface area) at the elevated temperatures experienced within the
converter/7) The Fe was present from the engine and exhaust system (i.e., rust
and engine wear products).
25
-------
VII. SCANNING ELECTRON MICROSCOPE
The surfaces of each biscuit were examined with the use of a scanning
electron microscope (SEM). A one cubic-centimeter piece was taken from the
front face of each biscuit. The internal surfaces of the individual cells from
each biscuit were examined for indications of lead deposits and other
indications of changes to the catalyst surfaces. Photographs of a typical
surface were taken and are included in Appendix E. All examinations and
photographs were taken at a magnification of X500. This magnification was
selected because the interesting structures could be examined without severely
limiting the field of view.
A typical example of what is probably a lead deposit on the surface is
shown in Figure 12. The deposits covering the surface of the catalyst have the
appearance of very fine grains spread evenly over the surface. Very few large
pores were observed. The physical structures for all of the A biscuits were
quite similar in appearance. The appearances of the surface for the B biscuits
were also similar, but different from the A biscuits. These had the appearance
of dried, cracked mud with the exception of two of the GM converters (307 and
941), which were unique in surface structure, and the Chrysler converter (309),
which was the converter with the highest lead concentration on the B biscuit.
Converter 307 also had a high lead and sulfur content on the B biscuit (10.67 g
lead or 1.^7 weight percent and 11.25 g sulfur or 1.55 weight percent). The
physical appearance of the B biscuit from the Ford converter (002) was very
similar to the A biscuits (fine grains), except that a number of cracks were still
visible. Some of the cracks appeared to be partially filled with the same
material that covered the surface. For dual catalyst vehicles, the physical
appearances of the individual biscuits were quite similar. The surface appeared
very smooth, with deep cracks and a number of large, randomly-dispersed
particles of unknown composition on the surface.
Figure 12. Typical example of catalyst surface from misfueled
vehicle (GM-vehicle 307)
'
-------
ANALYSIS OF TEST RESULTS
The results of the analytical procedures performed on the ten catalysts
evaluated during this project are most useful if they can be correlated with
changes in emission levels of the vehicles on which the catalysts were installed.
These catalysts were from vehicles involved in several different EPA studies,
and represented only a portion of the vehicles involved in each study. While the
catalysts did come from different studies, the studies all involved the
intentional use of leaded fuel in a catalyst vehicle. EPA furnished SwRI with
the vehicle emission test results and amount of fuel lead that was used in each
vehicle.
There are two types of statistical analysis that can be done on the
analytical procedure results from this study. One is a correlation study among
the results from the various analytical procedures. The second analysis is a
correlation between the analytical procedure results and both the fuel lead used
and the changes in vehicle emission levels.
Correlation Matrix of Analytical Procedure Results
As an initial step to determine if any correlation exists between the levels
of the various elements found on the catalyst, a correlation matrix of pairwise
regressions was obtained using the BMDP statistical computer program.
Included in the matrix were the values for each catalyst of percent by weight of
eight of the elements from the XRF analysis, plus the specific surface area in
m*/g from the BET analysis. This matrix is shown in Table 9. In the matrix, a
value of 1.0 indicates a perfect linear relationship. A negative value indicates
an inverse relationship. The highest value in the matrix is for the zinc and
phosphorus correlation. This is not surprising since a zinc and phosphorus
compound, zinc dialkyldithiophosphate, is an engine oil additive. The zinc and
calcium correlation, while much lower than the zinc-phosphorus correlation, is
also the result of both zinc and calcium being included in engine oil additives.
The second highest correlation coefficient is for nickel and sulfur. This
coefficient is negative, indicating that as nickel increased the sulfur level
decreases. The reason for this correlation is not immediately evident. As was
pointed out in a previous section of this report, nickel was found in the first
biscuit of each two-biscuit catalyst, except the catalyst from vehicle 309. The
amount of nickel in these first biscuits, on the order of two percent by weight,
is too large to be a result of engine wear. Since these systems were all three-
way (oxidation and reduction) catalysts, the nickel is presumed to be included in
the first biscuit as a reduction catalyst. The highest sulfur levels were in the
second biscuit, except for the catalyst from vehicle 9M. In a previous SwRI
study of oxidation catalysts conducted for EPA/8) sulfur levels were generally
higher in the first biscuit. Thus, while the sulfur level being higher in the
second biscuit appears to be a characteristic of three-way catalyst systems
with an oxidation catalyst as the second biscuit, it is difficult to ascribe a
cause-and-effect relationship to the correlation of nickel and sulfur levels. It is
interesting that there is only a slight negative correlation between lead and
surface area (labeled SSA in Table 9). One of the ways lead has been
29
-------
TABLE 9. CORRELATION AMONG ELEMENTS FOUND ON CATALYSTS
CA
Nl
ZN
PB
PT
PD
SSA
p
S
CA
N I
ZN
PB
PT
PD
SSA
1
2
3
4
5
6
7
8
9
1.0000
-.1842
.4507
.3137
.9380
.5601
.0344
-.3859
-.1756
1 .0000
-.0355
-.5919
-.2607
-.1186
-.0215
.1642
.0401
1.0000
-.0677
.5548
.0896
.0522
.1507
-.4760
1.0000
.3372
.5457
.2094
-.2024
.1952
1 .0000
.4975
.1053
-.2830
-.3241
1 .0000
-.1408
-.0367
-.1787
1.0000
-.0091
.3604
1 .0000
-.1234
1.0000
-------
hypothesized to poison catalysts is by reducing the surface area. No good
examples were available from this group of converters where lead poisoned the
catalyst without changing the surface area.
There are only two other correlation coefficients above 0.50. These
correlations are between lead and phosphorus and lead and nickel. Again, the
reason for these correlations is not obvious. These relationships may warrant
further study, but such investigation is beyond the scope of this project.
Correlation Matrix for Analytical Results from the Catalysts and
Vehicle Emissions
The EPA has furnished the results of the emission tests on the vehicles
from which the catalysts in this project were taken. The emission test results
were for FTP tests both before using leaded fuel and at the end of the vehicle
operation on leaded fuel. The percent change in each of the FTP emissions was
calculated. These values are shown in Table 10. The emission changes could
have been expressed in grams/mile. However, percent change was chosen in an
attempt to normalize the data, because of the large differences in the initial
CO emissions between cars (see Table 2). Since the emission results are for a
vehicle, if correlations to catalyst condition are desired, the various catalyst
parameters must be recalculated in terms of a single number for all biscuits and
catalysts associated with each vehicle. These recalculated values represent an
overall average level for the engine-catalyst system, and are shown in Table
11.
The overall catalyst parameters and the emission changes as well as the
amount of fuel lead put through each vehicle were used to generate another
correlation matrix. This matrix is shown in Table 12. As would be expected,
the highest correlation coefficient is for the lead retained in the catalyst and
the fuel lead put through vehicle, labeled GPB in Table 12. Thus, any other
variable that correlates well with one of these parameters will correlate well
with the other also. This can be seen in correlations between fuel lead and
phosphorus and between fuel lead and zinc. It is hypothesized that these
correlations are the result of the fuel lead scavengers also scavenging the zinc
additive from the oil, with subsequent deposition of the zinc and phosphorus on
the catalyst.
The correlation between zinc and phosphorus has been explained above.
The negative correlation between surface area and zinc and calcium, and to a
lesser extent, phosphorus and lead, probably results from some plugging of the
catalyst surface by these elements.
Elements such as platinum, palladium, and nickel which are part of the
catalyst when new, would decrease in weight percent as a catalyst increased in
weight due to deposits, particularly lead. The lead retained on the catalysts
examined increased catalyst weight approximately one to three percent. Thus,
for any element whose weight did not change over the test period, there would
be a negative correlation with lead. There is a strong negative correlation
between palladium and lead, and a much lower negative correlation between
platinum and lead. Nickel shows a slight negative correlation only with lead
31
-------
TABLE 10. PERCENT CHANGE IN EMISSIONS FOR EIGHT VEHICLES
OPERATED ON LEADED FUEL
Vehicle
No.
002
004
304
307
309
310
312
941
Study
No.
ATL #1
ATL //I
ATL #5
ATL #5
ATL //6
ATL #6
ATL //6
EPA In-House
Percent Change
HC
275.4
324.2
385.3
540.9
222.5
262.2
77.5
241.2
After Operation on
CO
235.6
11.4
164.4
97.0
43.7
17.2
10.3
95.8
Leaded Fuel
NOy
39.0
102.0
-2.3
68.4
-17.0
69.1
46.3
8.7
TABLE 11. AVERAGE XRF AND BET ANALYSIS RESULTS FOR CATALYST
SYSTEMS ON EIGHT CARS
Car
No.
002
004
304
307
309
310
312
941
Total Wt.
of Cat.
Material.^
775.4
936.6
1859.1
1619.7
1587.8
1647.4
1546.4
1671.2
Percent by Weight
P
0.04
0.22
0.14
0.00
0.00
0.02
0.04
0.00
S
1.00
1.50
0.90
1.20
0.90
1.00
0.60
1.00
Ca
0.01
0.03
0.02
0.00
0.02
0.02
0.10
0.00
Ni
1.00
0.00
1.10
1.00
0.00
1.30
1.00
0.80
Zn
0.04
0.03
0.02
0.00
0.00
0.01
0.01
0.00
Pb
2.70
2.30
1.90
1.60
1.20
1.50
1.00
1.30
Pt
0.11
0.15
0.14
0.16
0.10
0.26
0.15
0.14
<
Pd
0.10
0.07
0.13
0.11
0.19
0.20
0.20
0.10
Specific
Surface Area
m2/e
7.10
6.00
10.26
21.24
7.01
16.98
3.35
20.83
32
-------
TABLE 12.
CORRELATION BETWEEN CATALYST ELEMENTS AND EMISSION CHANGES
CA
Co
00
p
s
CA
N I
ZN
PR
PT
PD
SSA
HC
CO
NOX
GPP
CO
NOX
GPB
11
12
13
Nl
ZN
PB
PT
PD
SSA
HC
1
2
3
4
6
7
8
9
10
1 1
12
13
1 .0000
.5167
.1398
-.3557
.5947
.5214
-.0429
-.4655
-.4548
.1383
-.0894
.3968
.6566
1.0000
-.5426
-.4306
.2817
.5635
.0896
-.7333
.2360
.6140
-.0559
.6001
.3961
1 .0000
.0320
.0187
-.4066
.0359
.5120
-.6335
-.6748
-.4857
.1359
-.2188
1 .0000
-.0620
-.0416
.5097
.2257
.3986
.0987
.3494
.0303
.0528
1.0000
.8904
-.2662
-.4921
-.5638
-.0165
.4945
.3047
.8660
1.0000
-.1823
-.6874
-.2021
.3812
.6148
.3377
.9121
1.0000
.3370
.4244
.0643
-.4402
.5158
-.2364
1.0000
-.1854
-.5366
-.4430
-.2866
-.6127
^
1.0000
.5461
.0706
.0324
-.3138
ID
I .0000
.3375
.2216
.4145
CO
11
1 .0000
-.3518
.6342
NOX
12
GPB
13
1.0000
.2277
1.0000
-------
retained in the catalyst, but not fuel lead. However, it is known that not all
catalysts contained the same weight percent of nickel, a prerequisite for a
correlation of this kind. If it is assumed that all catalysts started with the
same weight percent of palladium, but not the same weight percent of
platinum, then catalyst weight gain could explain the high negative correlation
between lead and palladium.
There are other correlations that might warrant further study: sulfur
correlates reasonably well with phosphorus, calcium, and palladium. Calcium
and palladium, as well as nickel and platinum correlate moderately well.
However, investigation of these relationships is beyond the scope of this
project.
A discussion of the correlation of emission changes has purposely been
left until last. All vehicle emissions increased after being operated on leaded
fuel, except for NOX from vehicles 30* and 309. Thus, it would be reasonable
to expect good correlations between emissions and lead. Only CO shows even a
moderate correlation with lead. NOX and HC both correlate best with sulfur.
HC also has a moderate negative correlation with calcium and palladium. The
moderate positive correlation between HC and surface area is puzzling since
emissions would be expected to increase as surface area decreased. It must be
kept in mind that the emission values used were percent changes from baseline.
Of all the elements quantified, only lead could be presumed to be zero at the
baseline test. Therefore, correlations with elements other than lead may have
little meaning. Also, the correlation matrix is for linear relationships. Non-
linear relationships may not show high linear correlation coefficients. For this
reason, the relationships between change in emissions and lead retained on the
catalyst were examined in greater detail.
Effect of Catalyst Lead Levels on Vehicle Emissions
As mentioned above, all emissions on all vehicles increased after being
driven using leaded fuel, except for NOX emissions from vehicles 30* and 309.
The average percent increases were 291 percent for HC, 8* percent for CO, and
39 percent for NOX. The minimum, maximum, mean, standard deviation and
coefficient of variation of the percent changes in emissions are listed in
Table 13.
TABLE 13. SUMMARY STATISTICS FOR EMISSION CHANGES
FOR EIGHT CARS OPERATED ON LEADED FUEL
Percent Change in Emission Coefficient
Emission Minimum Maximum Mean S.D. of Variation
HC 77.5 5*0.9 291.1 134.3 *6.1%
CO 10.3 235.6 8*.* 81.5 96.6%
NOX -17.0 102.0 39.3 *0.6 103.3%
Since the eight vehicles whose emissions are included in Table 10
represent only a part of the vehicles used in the leaded fuel projects, the means
34
-------
given in Table 13 should be compared with the means from all the vehicles to
ensure that this subgroup is representative of the entire group of vehicles. The
emission results from all of the vehicles in the leaded fuel studies are not
available to SwRI at this time.
The large coefficient of variation indicates that the percent change in
emissions is a function of one or more parameters that vary from vehicle to
vehicle. An obvious parameter is the amount of lead retained in the catalyst.
To prevent the differences in catalyst size from confusing the results, retained
lead was expressed in terms of percent by weight for the total catalyst system.
The correlation matrix had shown that only CO demonstrated even a moderate
linear correlation with weight percent of lead. Plots of the percent changes in
emissions as a function of weight percent of lead retained in each catalyst are
shown in Figures 13, 1*, and 15 for HC, CO, and NOX, respectively. It is
difficult to see any trends, either linear or non-linear, in these plots. The
changes in emissions must therefore result from a number of other factors
along with retained lead.
The catalysts examined were from eight cars, representing four different
manufacturers and eight different engines. It is possible that each engine and
catalyst combination has its own relationship between catalyst lead and
emissions. If more catalysts were examined so that there would be a number of
data points for each engine, an analysis of variance could be performed to
determine if the change in emissions was a function of engine model.
Unfortunately, the current data set is not sufficient for an analysis of variance.
Thus, it is not possible from the information available at SwRI to determine the
reason for the large variation in emissions changes.
Catalyst Lead as a Function of Fueling Schedule
There were four different schemes used to put leaded fuel into the
vehicles whose catalysts were evaluated during this project. It was hoped that
the results of the catalyst analyses could be used to show what effect, if any,
the fueling scheme had on the amount of lead retained in the catalyst. If it is
assumed that the catalysts were all sized similarly for the engines on which
they were installed, and that engine thermal efficiency is close to the same
value for all engines, then the rate at which the lead was passed through a
catalyst, in terms of grams/minute per cubic foot of catalyst, should be
approximately the same for all vehicles. To alleviate the need to assume that
the catalysts were sized similarly, the grams of fuel lead were divided by the
weight in grams of each catalyst. For vehicles 30^ and 310, which were dual
catalyst vehicles, one half of the total lead used in the vehicle was assumed to
pass through each catalyst. This variable, grams of fuel lead per gram of
catalyst on a per catalyst basis, is a variation of the variable, grams of fuel
lead per gram of catalyst on a per vehicle basis, that was used in the
correlation matrix, and showed a high correlation between fuel lead and lead
retained. The relationship between fuel lead and lead retained on a per catalyst
basis is plotted as Figure 16. The different leaded fuel fueling schemes are
shown in the figure by different symbols. Note that the values of the fuel lead
parameter for each fueling scheme tend to cluster together at different levels.
None of the values from the every-fourth-tankful fueling scheme have values as
high as the every-tankful or every-other-tankful fueling scheme.
35
-------
w
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to
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o
V-l
-o
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0)
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700
600
500
400
300
200
100
Study
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A ALT #6
* EPA
Leaded Fuel
Every tank
Every-other-tank
Every-fourth-tank
Variable
_L
1
1
1
0.5 1.0 1.5 2.0 2.5
Lead in Catalyst, Percent by Weight
3.0
Figure 13. Percent change in Hydrocarbons
36
-------
en
C
o
•H
CO
CO
•H
O
CJ
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•H
(fl
.C
O
4J
C
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Leaded Fuel
Every tank
Every-other-tank
Every-fourth-tank
Variable
300 r
250 -
200
150
100
50
0.5 1 1.5 2 2.5
Lead in Catalyst, Percent by Weight
Figure 14. Percent change in CO emissions
37
-------
200
£ 150
o
•H
to
(0
•H
Q)
*100
o
2
C
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-------
Study Leaded Fuel
ALT #1 Every tank
ALT #5 Every-other tank
ALT #6 Every-fourth-tank
EPA Variable
40 i-
4J
U)
flj
-P
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u
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A
20
10
I
I
I
I
I
0.02
0.04 0.06 0.08 0.10
Grams of Fuel Lead/Grams of Catalyst
0.12
Figure 16. Percent of fuel lead consumed/grams of catalyst
39
-------
Thus, it is not possible to separate fueling scheme effects from effects
caused by the amount of lead. In other words, it is not possible to determine if
the higher lead retention seen in the ATL #6 vehicles for example, is caused by
the fueling scheme or the fact that less lead (on a per gram of catalyst basis)
was put through these vehicles, or a combination of these two factors. Since
there are additional vehicles that were operated under the leaded fuel test
programs, it might be possible to select additional catalysts for evaluation in a
future program, so that there would be sufficient data spread to determine the
relationship between amount of lead, fueling scheme, and lead retained in the
catalyst.
40
-------
REFERENCES
1. Michael, R.B. "Misfueling of Three-Way Catalyst Vehicles," Society of
automotive Engines, SAE 841354, 1984.
2. Demmler, A.W. Jr., "Automotive Catalysis," Automotive Engineering,
March 1977.
3. Goodell, P.O., Kane, R.H., and Tuffnell, G.W., "Copper-Chromium-Nickel
Alloys for NOX Automotive Emission Control Catalysts," SAE Paper No.
760318 presented at Automotive Engineering Congress and Exposition,
Detroit, Michigan, February 1976.
4. Klimisch, R.L. and Taylor, K.C., "Ammonia Intermediary as a Basis for
Catalyst Selection for Nitric Oxide Reduction," Env. Sci. Tech., Vol. 7,
1973.
5. Personal communication, R. Bruce Michael, Branch Technical
Representative, Environmental Protection Agency, June 1984.
6. Personal communication, James G. Barbee, Southwest Research Institute,
May 1984.
7. "Lanthology," Chemical and Engineering News, June 11, 1984.
8. Ingalls, M.N., "Catalyst Evaluation Testing of Used Catalysts," Draft
Final for EPA, Contract No. 68-03-3162, Work Assignment 10, May 1984.
9. Brunauer, S. Emmett, P.H., and Teller, E., Journal of American Chemical
society, 60, 309, 1938.
41
-------
APPENDIX A
SAMPLING AND ANALYSIS PROCEDURES
A. Radiograph of Whole Monolith Converters
B. Disassembly of Whole Converters
C. Sample Preparation and Distribution
D. Surface Area by BET Analysis
E. Elemental Analysis by X-Ray Fluorescence
F. Examination by Scanning Electron Microscope
G. Photographs of Converter Bisquits
-------
SAMPLING AND ANALYSIS PROCEDURES
For this project, the catalytic converters to be examined were received
completely intact, i.e., as removed from an automobile. The catalysts had to
be removed from the protective housing before the samples could be taken.
The methods used to remove the catalytic material from the converter
container and to divide the material into samples for analysis are explained in
this section.
A. Radiograph of Whole Monolith Converters
From previous work, SwRI had found that radiographs (x-rays) of whole
monolith converters could identify cracks, substrate meltdown, blowout and
other structural failures, prior to disassembling the converter. This knowledge
is needed to prevent inadvertent disturbance of these problem areas during the
disassembly process. The radiograph can also be used as a means of
determining lead deposition without opening the container.
The radiographic inspection of the catalysts was performed by the Quality
Assurance Systems and Engineering Division at SwRI. This division conducts
worldwide inspection of nuclear power plants, boilers and pipelines. The same
standards and procedures used in radiographic inspection of welded joints in
non-nuclear components such as pressure vessels and piping were used in
radiographing the monolith catalysts.
To obtain the radiographs, the converter was placed in the bottom of a
small (approximately 3 feet by 3 feet by 3 feet) lead lined chamber. The x-ray
source was an x-ray generator tube at the top of the chamber. The film was
placed directly under the converter (see Figure A-l). Initially, several
exposures were made at different radiation outputs (i.e., different voltage
inputs to the x-ray tube) to determine the optimum voltage setting and time of
exposure for the type converter being radiographed. Two exposures of each
converter were taken (one along the flat surface of the catalyst material and
one perpendicular to it). The SwRI Radiographic Review Records for each
individual catalyst inspected under this project are included in Appendix B.
This record lists the x-ray tube voltage and current, exposure time, and other
pertinent data and conditions. A representative radiograph of each converter
lying flat with respect to the film is presented in Appendix B. Appendix B also
contains the applicable portion of the SwRI Division 17 Operating Procedure for
Radiographic Inspections. This operating procedure was followed for this
project.
B. Disassembly of Whole Converters
Before the catalytic material could be divided into samples, the converter
container had to be removed. This was accomplished by:
1. Cutting the end pieces from each converter container about one half
inch from the face of the catalyst (See Figure A-2). The proper
cutting location was determined from an inspection of the whole
converter x-ray radiograph.
A-2
-------
x-ray source
Converter
Image
Catalytic
Converter
Film
Figure A-l. Schematic representation of whole converter x-ray
A-3
-------
Figure A-2. Cutting end pieces from container
Figure A-3. Grinding Seam Weld
A-4
-------
Surface Area
5ampIs
3EM Sancie
procedure for monolith
A-5
-------
2. Grinding off the longitudinal seam weld. Each end of the converter
container was taped to reduce the chance of damaging the catalytic
material and preventing metal filings and other debris from entering
the converter container during the grinding process. (See Figure
A-3)
3. Removing carefully one side of the converter container. Again at
this point, the whole converter x-ray radiographs were consulted to
identify which catalysts had fractures or other problems which
might be encountered during opening. The internal photographs
were then taken of each catalyst.
The exception to the above procedure was sample -00*. The VW catalyst
was slightly different from the other seven. After the two end pieces were
removed, the catalyst material was carefully pushed out of one end. This was
possible because of the structure design of this particular converter container.
As with the other converters, the x-ray radiographs were instrumental in
determining the best method to remove the catalyst material without damaging
the internal catalyst structure.
C. Sample Preparation and Distribution
Samples of the catalytic material were required for three different
analytical procedures. These procedures and the location of the samples taken
are presented in Table A-l. Each biscuit was quartered as shown in Figure A-4.
A7mmx7mm strip down the entire length was cut out of the center of
each biscuit. This sample was then broken into lengths about 2 to 3 cm long.
Sufficient pieces were required to give a total sample weight of more than 5
grams. These samples were labeled and sent to Micromeritics Instrument
Corporation for BET Surface Area analysis.
TABLE A-l. ANALYTICAL PROCEDURES AND SAMPLE DISTRIBUTION
Test Procedures Sample Location
BET Surface 7 mm x 7 mm strip down entire length of
Area (specific the biscuit
area in m^/g)
SEM + surface 1 cm cube from front face of B
x-ray fluorescence
(pore structure and
surface analysis
for noble metals
and poisons)
Bulk x-ray B and C ground up together and
fluorescence representative sample taken
(total noble metal
and poison concen-
trations)
A-6
-------
The sample for the SEM, a 1 cm cube, was taken from the upstream face
of the catalyst material. This method of sampling was chosen because the
whole catalysts X-ray radiographs showed that the heaviest lead deposition was
located in this area. Once the sample was prepared, it was sent to the U.S.
Army Fuels and Lubricants Research Laboratory (Division 02) at Southwest
Research Institute for analysis.
One front quarter and the rear quarter from the opposite side were
selected for bulk x-ray fluorescence. These quarters were combined in a
mortar and crushed by the pestle until a fine powder resulted. This method was
chosen to average the noble metal and catalyst poisons over the entire catalyst.
The resulting powder was sent the U.S. Army Fuels and Lubricants Research
Laboratory (Division 02) at Southwest Research Institute for subsequent
analysis.
D. Surface Area by BET Analysis
Automobile exhaust catalysts require large surface areas at the molecular
level to provide sufficient exposure of the exhaust gas to the actual catalytic
element. In automotive applications, the gamma form of alumina (A1203) is
universally used as the material on which the noble metal catalyst is deposited,
precisely because gamma alumina has a high surface area at the molecular
level. In a used catalyst, this surface area can be reduced as a result of
plugging by exhaust constituents, deposition of a catalyst poison, or by
overheating the alumina (above 1000°C), causing a change in the alumina
crystalline structure to the alpha alumina form. The alpha form of alumina has
a lower surface area and is stable at low temperatures. Thus, once formed, the
alumina retains the alpha structure even after cooling to normal catalyst
operating temperatures. Measurement of the surface area of a used catalyst
permits comparison with new catalysts to determine if there is still sufficient
surface area for adequate exposure of the exhaust gases to the noble metal
catalyst molecules.
Surface area is measured in terms of specific surface area (square meters
per gram) by the BET physical adsorption method. The initials B.E.T. are for
the three researchers, S. Brunauer, P.H. Emmett, and E. Teller, who first
proposed the theoretical basis for calculating the volume of gas adsorbed on a
surface in 1938.W The usual form of the equation resulting from that theory,
called the BET equation, for adsorption of a gas at a constant temperature is:
x =
v(l-x)
where:
vm = the volume required to cover the entire surface with a
layer of the gas one molecule thick
v = the volume of the gas actually adsorbed on the surface
C = a dimensionless constant greater than one, and
dependent on temperature only
x = the ratio of the pressure of the gas in the container to
the saturation pressure of the gas, referred to as the
relative pressure, P/P0
A-7
-------
A plot of x/v(l-x) versus x, for various values of x is a straight line
between x = 0.05 and x = 0.3. From the slope, S, and the intercept, I, of this
straight line, both vm and C can be determined, as follows:
and
S+l I
Thus, if x and v are known, vm, the volume of gas to cover the surface with a
layer one molecule thick can be calculated. The total surface area of the solid
is then calculated from the equation:
A = N0vm
where:
A = surface area of sample
N0 = Avogadro's number
= cross-sectional area of adsorbed molecule
There are a number of procedural methods and apparatus designs to infer
v, the total volume adsorbed, at various measured values of x, the relative
pressure ratio. Basically they fall into two classes: gravimetric and
volumetric. Both methods use the BET equation above. They differ in that the
gravimetric method measures the weight gain of the sample after adsorbing the
nitrogen gas, while the volumetric method infers the amount of nitrogen
adsorbed on the sample by Pv relationships. One example of a gravimetric
technique is the ASTM "Standard Test Method for Surface Area of Catalysts,"
ASTM D3663-78. The procedure used in this project utilized a volumetric
technique.
Since SwRI does not have the necessary equipment to perform the BET
analysis, this work was subcontracted to Micromeritics Instrument Company,
which manufactures equipment for BET analysis and provides a laboratory
service using their equipment. The Micromeritics Digisorb 2600, a
microcomputer controlled BET apparatus, was used to determine the specific
surface area of all samples examined for this project. This instrument uses
mixtures of nitrogen and helium gas cooled to liquid nitrogen temperature.
Nitrogen will determine the area of the surface with any cracks or pores larger
than the diameter of diatomic nitrogen. Since most of the exhaust gases are
higher molecular weight than nitrogen, the reported surface area will be
slightly higher than the surface area where catalysis takes place, this
technique is the "state-of-the-are" technology. The degree of accuracy for this
analytical procedure is about 1 m^/g. The printout of the Digisorb 2600,
showing the BET slope, intercept, C, and vm for each of the catalyst samples
are included in Appendix D.
E. Elemental Analysis by X-Ray Fluorescence
The ability of a catalytic converter to perform as designed can be
adversely affected by certain elements that can be present in engine exhaust.
One of the major "poisons" of automotive catalysts is lead. All gasoline, even
that labeled "unleaded," contains some lead, so lead may even be present in
A-8
-------
catalysts that have been installed on vehicles which have never used leaded
gasoline. Other elements that are deleterious to catalyst operation are: sulfur
(S), phosphorus (P), manganese (Mn), calcium (Ca), and zinc (Zn). In addition,
converter operation can be adversely affected if there is a loss of the actual
noble metal catalyst itself from the converter substrate. To determine the
extent of poisons and the amount of noble metal catalyst in the converter, a
method of determining small quantities of various elements is required. For
elemental analyses, this project used x-ray fluorescence (XRF) spectrometry
techniques, also referred to as energy dispersive x-ray spectrometry (EDS).
XRF is both a qualitative (element identification) and quantitative (amount of
element) procedure.
The basic principle of XRF is that all elements will emit (fluoresce) x-
rays when bombarded by high energy photons (x-rays or gamma rays). The
energy level of the emitted x-rays in electron volts identifies the element. The
reason for this can be seen by examining what happens to an atom when
bombarded by photons.
Most of the photons impinging on an atom interact with the orbital
electrons of the target atom in what may be considered as non-specific
interactions, and result in little or no disturbance of the orbital electrons.
However, some interactions result in the ejection of electrons from their orbits.
The resulting vacancies, or holes, represent high energy, unstable states. If
these orbital vacancies are in the innermost shells, electrons from outer shells
cascade to fill them, resulting in a lower energy, more stable state. The energy
released by the process produces x-rays. Each of the transitions which occur
leads to the emission of x-ray energy at levels which are characteristic of the
target element and the transition involved. This process is shown schematically
in Figure A-5. By measuring the energy of the x-rays emitted, the element can
be identified. By counting the number of x-rays at that energy level, the
amount of the element can be determined by comparison to a standard. While
the theory is simple, practical application requires a suitable detector and a
computer to process the signal. A suitable detector was developed in the mid-
1960's, and the development of the microprocessor in the 1970's made XRF
equipment a laboratory reality.
For this project, the XRF analysis was performed by the Army Fuels and
Lubricants Laboratory, operated by SwRI for the U.S. Army. The equipment
used was an EXAM 902 detector together with an EDAX 707B analyzer, both
manufactured by EDAX International, Inc. A photograph of the system is shown
in Figure A-6. A schematic of the EDAX system is shown in Figure A-7.
One half of the catalyst material was ground into a course homogeneous
powder with a large mortar and pestle. A portion of the sample was then
ground into a very fine powder, mixed with an organic binder, placed in an
aluminum cup, and pressed into a small briquette approximately 1 1/4 inches in
diameter and 3/16 inches thick. The sample briquette is placed in the EXAM
sample holder, the sample chamber purged with helium, and the x-ray
bombardment begun. The stepwise procedure is listed in Table A-2. The run
continues until a total of 40,000 counts (total of all energy levels) have been
accumulated. This results in a determination of element quantity within
approximately 2.5 percent. The counts at energy levels corresponding to the
A-9
-------
Figure A-5. X-ray energy emitted by an atom that
has lost electrons in the inner shells
A-10
-------
Figure A-6. EDAX/EXAM system
A-ll
-------
Figure A-7. Schematic of EDAX/EXAM system operation
A-12
-------
energy levels given off by the various elements sought are printed out by the
computer. The energy spectrum from 1.28 to 11.02 KeV for each biscuit are
included in Appendix D. The counts per second from the individual energy
"lines" for each element in the sample are used to calculate the percent by
weight from a regression equation developed from several runs of different
concentrations of standards of each element. In this project, the percent by
weight was obtained for the following elements: sulfur, phosphorus, calcium,
manganese, zinc, nickel, lead, platinum, palladium, and rhodium.
TABLE A-2. STEP WISE PROCEDURES FOR ELEMENTAL ANALYSIS OF
AUTOMOTIVE CATALYST SAMPLES BY XRF
1. Grind weighed amount of sample with 10 percent Somar-Mix powder
added until a very fine, homogeneous powder is obtained.
2. Fill aluminum cap (Somar-Cap) with blended powder.
3. Press into pellet using hydraulic press.
4. Analyze samples using the energy dispersive x-ray system. Run analysis
to 40,000 counts, total.
a. equipment: EXAM 902 detector
EDAX 707B analyzer
b. conditions for elements S, P, Ca, Mn, Zn, Pb and Pt:
Silver x-ray source tube
3 minute purge with helium
20 Kv voltage
64 a current
c. conditions for elements Pd and Rh:
Gold x-ray source tube
3 minute purge with helium
29 Kv voltage
8 a current
5. Enter counts per second over background obtained for each element in a
sample into the XRF regression programs, using coefficients obtained
from multipoint analysis of standards.
6. Standards are run using procedure steps 1 and 4 above. Standards are
prepared by weighing out pure oxide forms of each element in a matrix of
20 percent aluminum oxide (to approximate the catalyst base material)
and Somar-Mix briquetting material.
The repeatability of the analytical system was determined with a series of
five repeat runs on a sample of known initial concentrations for the various
elements. This sample was blended with clean catalyst substrate material
A-13
-------
(alumina) obtained from W. R. Grace to simulate as close as possible the
conditions of a catalyst sample. The results of the repeatability experiment are
presented in Table A-3. The standard deviation of the five repeat runs was less
than 1 percent except for the elements platinum and sulfur. Sulfur was the
worst with a standard deviation of 0.041. The percent change of the mean
values for the five repeat runs to the actual concentration in the sample was
below 5 percent except for sulfur with -14.2 percent. This was probably due to
the overlap of energy levels when lead and sulfur are present in the same
sample.
TABLE A-3. REPEATABILITY EXPERIMENT FOR X-RAY FLUORESCENCE
Repeat Runs, wt. % Standard Actual Percent
Element 1 2 3 4 5 Mean Deviation Cone. Change
P 0.265 0.268 0.264 0.273 0.256 0.265 0.006 0.27 -1.9
S 0.303 0.226 0.217 0.292 0.290 0.266 0.041 0.31 -14.2
Ca 0.048 0.054 0.051 0.052 0.046 0.050 0.003 0.05 0.0
Mn 0.381 0.394 0.393 0.380 0.379 0.385 0.007 0.38 1.3
Ni 0.247 0.258 0.258 0.253 0.244 0.252 0.006 0.25 0.8
Zn 0.082 0.083 0.085 0.083 0.081 0.083 0.001 0.08 3.8
Pb 0.177 0.181 0.194 0.182 0.170 0.181 0.009 0.18 0.6
Pt 0.298 0.335 0.309 0.312 0.315 0.314 0.013 0.30 4.7
F. Examination by Scanning Electron Microscope
The ability of a catalytic converter to function correctly is very much
dependent on the microscopic topography of the catalyst substrate. A scanning
electron microscope (SEM) was used to examine this topography. The scanning
electron microscope is simple in principle, but complex in execution.
Interpretation of results for the most part, follows from observations made with
the naked eye or optical microscopes. Thus, it is not incorrect to say that the
SEM is an extension of the human eye; all that one is doing is increasing the
magnification and resolution of the eye. The SEM bombards the sample with
electrons rather than with visible light. When using electrons rather than
visible light, two advantages occur: a wavelength much shorter than visible
light is generated and the source is nearly all the same wavelength. Shorter
wavelengths permit higher resolution and monochromatic radiation permits
simpler lens design. The electrons are focused by either electrostatic or
electromagnetic lenses. The lenses are arranged in a typical SEM column as
shown in Figure A-8. Control of the intensity, wavelength and penetration of
the electron beam gives a flexibility to the SEM for which there is no parallel in
optical microscopy. This flexibility does add to the complexity of operation of
the SEM, however.
The specimen illuminated by the electron beam both scatters and absorbs
the electrons. The absorbed energy is reemitted as x-ray, secondary electrons,
and auger electrons. Figure A-9 illustrates this process. Surface topography
contrast is usually determined by use of secondary electrons, those very low
energy electrons which can penetrate only a small amount of material, thus
originating close to the surface. Secondary electron detectors are usually
A-14
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Electron source
Spray aperture
1 First lens
J(condenser)
Column liner
Stigmator coil
Scan coil
Final lens
(objective)
Scan coil
Objective aperture
Scanning electron
beam
Camera
/ V
Cathode ray
display tube
(visual)
Secondary collector
Cathode ray
display tube
(camera)
Specimen
Video
Amplifier
Figure A-8 . Schematic of scanning electron microscope
-------
Primary
iHctron team
X-rays
Saccrwary jno
Aug.tr tltctrons
10 to 50 Angstrom-
limit of secondary tltetrons
About 2000 Angstroms -
limit at arimary eitctrons
^- Eaual tnergy
dissioation profilM
Figure A-9. Forms of emitted energy from a
specimen in a SEM
A-16
-------
photomultiplier tubes located to the side of the sample as shown in Figure A-8.
Because alumina is a good insulator, when the electron beam strikes the
catalyst sample for any period of time, a static charge is built up. This static
charges completely "washes out" any detail in the cathode ray tube display. To
prevent static charge buildups, after the sample had been mounted on an SEM
sample holder, the sample and sample holder were coated with a thin layer
(several molecular layers thick) of gold by vapor deposition, to ground the
sample.
An AMR Corporation, Model AMR 1200 scanning electron microscope was
used to examine the catalyst samples from this project. Figure A-10 is a
photograph of the AMR 1200. This SEM is equipped with an automatic filament
control. Operator control is needed only to select one of the three acceleration
voltages available (5, 15, or 30 kV). The operator can also select one of three
final aperatures for control of depth of focus, incident current and resolution.
For this project, an acceleration voltage of 30 kv was used. The smallest (100
micron) final aperature was used for best visual resolution. A sample tilt angle
of 30° was generally used. Appendix F contains micrographs of typical surfaces
for each of the catalysts.
A-17
-------
Figure A-10.
Photograph of AMR Corporation, Model AHR1200
scanning electron microscope
A-18
-------
002-A !:=::::::::
00 2-B §£:=:,.
JUjjiiHiJIIHII!! Hi::.
Figure A-ll. Front face view of 002
A-19
-------
Figure A-12. Front face view of 004
A-20
-------
Figure A-13. Front face view of 304-1
A-21
-------
304-2-A
304-2-B
Figure A-14. Front face view of 304-2
A-22
-------
Figure A-15. Side view of 307
A-23
-------
Figure A-16. Front face view of 307
A-24
-------
Figure A-17. Front face view of 309
A-25
-------
Figure A-18. Front face view of 310-1
A-26
-------
Figure A-19. Side View of 310-2
A-27
-------
310-2-Ai
-IO-2-B,
Figure A-20. Front face view of 310-2
A-28
-------
Figure A-21. Side View of 312
A-29
-------
312
k
Figure A-22. Front face view of 312
A-30
-------
No. 941
Figure A-23. Front face view of 941
A-31
-------
APPENDIX B
RADIOGRAPHIC RECORDS AND RADIOGRAPHS OF WHOLE
MONOLITH CONVERTERS
-------
SOUTHWEST RESEARCH INSTITUTE
DIVISION 17
OPSHAT1NG PROCEDURE ?*8* L °f L5
OP-17-40-001
Revision L
July 1982
RADIOSRAPETC INSPECTION OF
NON-NUCLEAR COMPONENTS
1. PURPOSE
1.1 This procedure describes the requirements for shop or field radio-
graphic examination of welded joints in non-nuclear pressure ves-
sels, piping, nozzles, and similar configurations. This procedure
compiles with the minimum requirements of the ASME Boiler and
Pressure Vessel Code, Sections 7 and Till, 1980 Edition, plus
addenda through Winter 1981.
1.2 This procedure shall be applicable to welds containing consumable
inserts, back-up rings, or strips where radiography is required by
specification, procedure, code, or contracted agreement.
2. REFERENCE
2.1 ASME Boiler and Pressure 7essel Code, Section 7, Articles 2, 1980
Edition plus addenda through Winter 1981.
2.2 When the requirements of this procedure and ASME Section 7 aeet or
exceed the requirements of other codes or standards, including but
not limited to ASME Section VIII, Division 1 and 2, HA7SHIPS
0900-006-9010, American Welding Society AWS Dl.l, American Bureau of
Shipping, and American Petroleum Institute API 1104, the acceptance
criteria may be included in this procedure as an appendix.
2.3 Any special requirements necessary to meet the referenced code or
standard may be included in the appropriate appendix and will become
a part of this procedure for radlographic examination of such
components.
3. PERSONNEL
3.1 All personnel performing radiographic examinations shall be
qualified in accordance with ASNT SNT-TC-LA.
RESPONSIBILITY
4.1 The Director of the Department of Research and Development within
the Quality Assurance Systems and Engineering Division shall be
responsible for the initiation of che procedure.
B-2
3T TaATt I TSHNICU. **vf* icurs! ;cqNiz*#7 ZO&Z'z* .CAT; : *s
• ."•=-, I 7/.,._ I ^'Z+R****^*^ - 17/52.1 /sSA-^S
S3 - »o -ia
V
-------
SOUTHWEST RESEARCH INSTITUTE
DIVISION 17
i OPERATING PROCEDURE
6.2
6.3
6.4
„ -6-5
OP-17-40-00I
Revision 1
July 1982
Pag* 3 of 13
6.1.4 Fila brand or type and number of films in cassette.
6.1.5 Type and thickneaa of intenaifylng screens and filters.
6.1.6 Blocking or masking techniques, if used.
6.1.7 Minimum source-to-fila distance (SFD).
6.1.3 Sketch showing exposure geometry.
6.1.9 Description of or reference to the welding procedure, where
applicable.
Radiographs demonstrating the expoaure techniques shall be
maintained and kept on file.
In cases where the production radiograph is used as the radiographic
procedure qualification, the radiographic fila shall be filed in
accordance with the contract requirements.
An exposure technique shall be established for each component
radiographed. A new technique shall be established for the
following changes:
6.4.1 Bach different type of radiation source used; i.e., the use
of different X-ray voltages or a change in type of isotope.
6.4.2 A change to a faster fila.
6.4.3 The use of fewer or thinner lead screens.
6.4.4 Each change in basic exposure geometry; i.e., single wall,
double wall, elliptical expoaure, step-weld joint, etc.
The applicable exposure techniques shall be referenced on the
Radiographic Interpretation Report of each weld radiographed.
Figure 1 is a typical Radiographic Interpretation Report Fora.
7.0 MATERIAL THICKNESS AMD
This procedure covers the material thickness range from 0.2 to 6.0
inches, unless specifically prohibited.
B-3
'.VHJTTSJ4 3T I OATt I TtDlNICW.
I OATS
:'CAT3 I JS
strut
- M-4
-------
SOUTHWEST RESEARCH INSTITUTE
DIVISION 17
OPERATING PROCEDURE
OP-L7-40-00I
Revision 1
July 1982
Page 5 of 15
12.2
13. FILM
14.
Radiograph* shall be made of completed velds In accordance with this
procedure. However, this does act preclude the use of radiography
at other stages of fabrication such as partially completed welds or
welds during repair operations.
Types 1 and 2 Radiographlc Film, such as Eastman Kodak M, I, AA, or
equivalent, shall be used; the type to be used is dependent on the
part being radiographed.
SCREENS
14.1 A front and a back lead intensifying screen shall be used in all
exposures above 120 K7 and for all isotope exposures. When neces-
sary, lead screens nay be used for exposure at or below 120 £7.
Fluorescent screens shall not be used.
15. FILM AND SOURCE PLACEMENT
15.1 Film cassettes shall be loaded with one film or two films with "sand
wich" construction of lead screen and film. Screen thicknesses
shall be appropriate for the energy level of the radiation source.
15.2 The film cassette shall be as close to the surface of the area of
inspection as practicable.
15.3 The cassette shall be firmly fixed and maintained to the surface of
the component during exposure.
15.4 The source shall be free of movement during exposure of film.
16. EXPOSURE
16.1 The exposure time shall be such as to produce a film density in
accordance with Section 7, Paragraph T-234, and shall, in no case,
be less than 2.6 for composite viewing or exceed 4.0. The density
shall be evaluated by using an ASA density comparison strip or a
densitometer.
16.2 The geometric unsharpness of the resultant radlographic image shall
not exceed the requirements of ASME Section 7, Paragraph T-251, when
required by the referencing Code.
X
16.3 A lead symbol "3" is Co be used as a back scatter check; it shall be
attached to the back side of the cassette in accordance with Section
7, Paragraph T-235. 3-4
"IN 3Y
3ATt
asvf* lOATti
ISC73K
S3
7/92-1
7/ZZ
twin
«M— o
-------
SOUTHWEST RESEARCH INSTITUTE
DIVISION 17
\ OPERATING PROCEDURE
OP-I7-40-001
Revision 1
July 1982
Pag* 7 of 15
21. RZZIAMISATION ATCZR REPAIRS
21.1 Welds showing unacceptable defects shall be repaired in accordance
with the welding repair procedure and then reexaained by che sane
radiographic technique and procedure as was uaed originally. All
resulting fila records shall be permanently identified as subsequent
repair radiographs and retained as a permanent part of the record.
22. RECORDS
22.1 Radiographic filas and records shall be filed by the Project Manager
for the period required by contract unless otherwise agreed to by
the interested parties. Exposure conditions shall be written on an
accompanying fora essentially the sane as the one shown in
Figure B-l of this procedure* An accurate sketch of the radio-
graphic setup shall be presented at the time of film interpretation.
,„„,
-------
SOUTHWEST RESEARCH INSTITUTE
DIVISION 17
i OPERATING PROCEDURE
OP-17-40-001
Revision 1
July 1982
Page 9 of 15
SCUTHWtST ««31AKOI INSTTPUTl
I At
I ' I
1
FIGURE 1. SOUTHWEST RESEARCH INSTITUTE
RADIOGSAPHIC REVIEW RECORD
B-6
3Y
i OATS i
••o
-------
SOUTHWEST RESEARCH INSTITUTE
RADIOGRAPHIC REVIEW RECORD
Sponsor £>/tf,
Weld I.D.
System
Project No.^T?- 77
Material x^TV^wrT
Date 3-
Date Rt.J3 -
Weld Thickness
Shooting: Single Wall,
Source Size
X-Ray K.V._
Film Evaluation:
One Wall on Film.
Curies_
"M.A. "
Shim
Double Wall
SFD
_Pipe Size
Penetrameter
Film Type
Time
FS/SS
S/D
-------
'SOUTHWEST RESEARCH INSTITUTE
RADIOGRAPHIC REVIEW RECORD
Sponsor !D/lJ. TTT
Sy»tem_
Project No.
Weld I.D.
Weld Thickness
Shootings Single Wall
Source Size
X-Ray K.V.
-------
SOUTHWEST RESEARCH INSTITUTE
RADIOGRAPHIC REVIEW RECORD
Sponsor Dj
-------
SOUTHWEST RESEARCH INSTITUTE
- RADIOGRAPHIC REVIEW RECORD
Page_/of.
Sponsor_
Weld I.D.
Weld Thickness
System
Project No.^g-
Material £47X4 K? 1~
Shim
Date Rt. -3 -
Shooting: Single Wall_
Source Size
X-Ray K.V. .
_Curies_
"M.A. "
_DoubleWall_
SFD
Pipe Size
Penetrameter
Film Type
Time
FS/SS
S/D
SFD
"* Time s
Film Evaluation: Reading: Single Filnr
One Wall on Film
Double Film
Both Walls on Film
Sketch Showing Setup
Radiographer
SNT-TC-IALevel.
Ass't Radiographer
SNT-TC-IA Level_
Reviewed By
SNT-TC-IA Level
Applicable Code.
Ttchniqu* Dud
Sourc*
Sourc* •
NOTE: T-3 may also be used for plate
Procedure Used
Film
Ident.
COMMENTS
Area of I merest.
Penetrameter
Difference
/J7
B-10
(=orm SwRI NOT-BO-1, Rev. 1
-------
SOUTHWEST RESEARCH INSTITUTE
RADIOGRAPH1C REVIEW RECORD
PagejLof(_
2> ft)'. 777".
System
Weld I.D.
Weld Thickness
Shooting: Single Wall
Sourer Size
X-Ray K.V.
Film Evaluation: Reading: Single Ftlm_
On* Wall on Film_
Double Film
Both Walls on Film
Sketch Showing Setup
Radiographer^
Taehniqu* Ui*d
SNT-TC-IA Level
Ass't Radiographer
SNT-TC-IA Level_
Reviewed By
SNT-TC-I A Level.
Applicable Code _
Source
Source
Sourci •
NOTE: T-3 may also be used for plate
Procedure Use
Film
(dent.
&
I
o
COMMENTS
Area of Interest
Penetrameter
Difference .
//?/ //f /,/¥/./£. /.la /.I7 //V /.^
9* J.0? //*
B-ll
Form SwRI NOT-RO-1. Rev. 1
-------
SOUTHWEST RESEARCH INSTITUTE
RADIOGRAPHIC REVIEW RECORD
Page_/of /
System
Sponsor
Weld I.D.
Weld Thickness
Shooting: Single Wall,
Source Size
X-Ray K.V._
Film Evaluation:
On*Walton Rim
Project No.^T?- ~7T?^~// 7
Date ^ -?-
. Date Rt. 3-7-
Curies
~M.A. "
Shim
Double Wall
SFD
_J»ipeSize
Penetrameter
Type
Time
FS/SS
SFD -32.
Time
Reading: Single Film
Double Film
Both Walls on Film £
Sketch Showing Setup
Radiographer
SNT-TC-IA Level.
A»'t Radiographer_
SNT-TC-IA Level
Reviewed Bv
SNT-TC-IA Level.
Applicable Code.
Ttehniqu* UiMi
) —
*,
Soure
Soure*
Sourc* •
NOTE: T-3 may also be used for plate
Procedure Used
Film
Ident.
Q
1
'3T
ec.
Z
'*«
o
w
O
Q.
• -•
r a
| Linear Indication |
n.i
1
CO
a
J Overgrind
| Crater Crack ]
| Crack(s) |
| Tungsten |
UL
q
J
0.°
q
| Undercut (IDOD)!
fl
I
/}
k
f
c
3
CQ
fl
f
,6
r
COMMENTS
Penetrameter
Diffprpnrp ..... ,,. ._ .
>7*/5
/^i /^ .9JT.93 .9/ .9? ;, c".
,$o .&6f ,~?3 .^
. £,
-------
SOUTHWEST RESEARCH INSTITUTE.
RADIOGRAPHIC REVIEW RECORD
Sponsor Q / /.
Weld I.D. 3>#-/
Weld Thickness
Shooting: Single Wall
Source Size Cviries_
X-Ray K.V.
System
Project NoX£?-
Date
Date Rt.
Shim
Double Wall_
SFD
Pipe Size
Penetrameter
Film
FS/SS
S/D
Tim*
SFD
Film Evaluation:
One Wall on Film
Reading: Single Film
Double Film
Both Walls on Film
Sketch Showing Setup
Radiograph
SNT-TC-IA
Ass't Radio
SNT-TC-IA
Reviewed E
NT-TC-IA
\pplicabla C
Film
Ident.
<8
er /^^/ ^^^ Jffj&^s ^^^j Ttchniqu* Used / ** ?• i
Level
graph*
Level
y 6
l£ ^Soure.
„ ^ //^\ /^^S°ur/^\
^ "'[ * ) ( ' « ) ( « )
^ ^^^: \ \ y \^ ^/ v_y
-• f Source — J
:od
.£
»
O
r Indication
/A?37
/J< /?7 /^y AT2. /^/ /I 5? /«9 X^^
/. ^7
fjf, /J/ /.// //fl /I? /->i X/<- X^/
/./7
-------
SOUTHWEST RESEARCH INSTITUTE
RADIOGRAPH1C REVIEW RECORD
Page.
&L-
Sponsor £>//. JuT"
System
Project No.
-~73"$ ^'
Weld I.D. 2
Weld Thickness
Shooting: Single Wall_
Source Size
X-Ray K.V._
Film Evaluation;
On* Wall on Film
Material
Shim
Curie*.
~M.A. "
Double Wall__
SFD
£_Pipe Size
_Penetrameter
~ Film
Time
SFD
Time
Reading: Single Film_
Double Film
Both Walls on Film
Sketch Showing Setup
Radiographer
SNT-TC-IA Level.
Ass't Radiographer,
SNT-TC-IA
Reviewed By
SNT-TC-IA Level.
Applicable Code _
Ttehniqu* U*«d
Film
Source •
NOTE: T-3 may also be used for plate
Procedure Used t&/**—/'?- »-£> -<#<&/
Sourc*
Film
Ident.
V)
o
u
U
CD
COMMENTS
Density Average.
Area of Interest.
Penetrameter
Difference .
L
j_
B-14
-otm SwRI NDT-RO-1. Rev. 1'
-------
SOUTHWEST RESEARCH INSTITUTE
RADIOGRAPHIC REVIEW RECORD
System
Sponsor
Weldl.D. 2
Weld Thickness
Shooting: Single Wall_
Source Sii»
X-Ray K.V.
Film Evaluation:
One Wall on Film
Project No.
Material
Date
OateRt.
Pipe Size
Curie»_
~M.A. "
Shim
Double Wall
SFD
Penetrameter
FS/SS
Film Type i
Time
S/D
77XT
Reading; Single Film_
Double Film
Both Walts on Film
Sketch Showing Setup
Radiographer^
Twhniqu* U»«d
SNT-TC-IA Level
Ass't Radiographer
SNT-TC-IA Level_
Reviewed By
SNT-TC-IA Level.
"*T*
Soure*
Film
Source •
NOTE: T-3 may also be used for plate
Procedure Used
&
COMMENTS
Area of I nterest.
Penetrameter
Difference
/.ii
xir
/J>j> /./?
&• <4i&tv
-------
SOUTHWEST RESEARCH INSTITUTE
RADIOGRAPH1C REVIEW RECORD
Sponsor £>/(/. ZZZ"
System
Date
Project
Weld I.D.
DateRt. J?
Pipe Size
Weld Thickness '
=f
&<4
t
Shooting; Single Wall
Source Size
X-Ray K.V. / 5
Film Evaluation:
One Wall on Film
Shim
_^,
/^S
Double Wall
Curies
S<2 M.A. -V
Reading:
Single
SFD ^
Film ,__
SFD
f ^ ff
Both
Time x-f
Double
Walls on Film
Penetrameter _^J^,
Film Type /<^^
Time
T/^*f^
-------
INLET
OUTLET
Figure B-l. Whole catalyst x-ray of 002
B-17
[
-------
INLET
OUTLET
Figure 8-2. Whole Catalyst x-ray of 004
B-18
-------
INLET
OUTLET
Figure B-3. Whole catalyst x-ray of 304-1
B-19
-------
INLET
OUTLET
Figure B-4. Whole catalyst x-ray of 304-2
B-20
-------
TNT FT
OUTLET
Figure B-5. Whole catalyst x-rav of 307
B-21
-------
TNT.KT
OUTLET
Figure B-6. Whole catalyst x-ray of,309
B-22
-------
TNLET
OUTLET
Figure B-7. Whole catalyst x-ray of 310-1
B-23
-------
TNI,FT
OUTLET
Figure B-8. Whole catalyst x-ray of 310-2
B-24
-------
INLET
OUTLET
Figure B-9. Whole catalyst x-ray of 312
B-25
-------
INLET
OUTLET
Figure B-10. Whole catalyst x-ray of 941
B-26
-------
APPENDIX C
SURFACE AREA BY BET ANALYSIS
-------
MCROMERITIC3 INSTRUMENT CORPORATION
DIGISCS3 2SOC V2.C2
101
PAGE
3-JTHWEST RSCH, OC2-A, MAL# 850-46
•ATICN 1' STARTED 4/ 4/84 8:30
NITROGEN
COMPLETED 4/ 4/S4 12112
ADSORPTION ISOTHERM
15i.5430 CC
P/PO
ES'JILIBRATION INTERVAL: 20 SECS
VOL INCREMENT: 100.000 CC/G STP
VOL ADSORBED
(CC/G AT STP)
0.0547
O.C73S
0. 11 36
0.1 5S7
0.2000
2 . OSSO
2.2045
2.3733
2.53E3
2.SS22
ICS INSTRUMENT CORPORATION
DIGISORB 2600 V2.02
101
SOUTHWEST RSCH, 002-A, MAL# B50-4S NITROGEN
3TATION 1 STARTED 4/ 4/84 8Z30 COMPLETED 4/. 4/84 12I12
PAGE 2
SPECIFIC SURFACE AREA
BET SURFACE AREA!
SLOPE:
INTERCEPT:
c:
VM:
3.6385 +/-
0.448156 +/-
0.003483 +/-
123.4422
2.2141 CC
0.0188 SG M/G
0.000874
0.000117
RELATIVE PRESSURE RANGE: 0.05GO TO 0.2ICO
C-2
-------
ivT CORPORATION
DIG! SORB 2EOO V2.0
PAGE
STATION 2
KSCH, CG2-B, MAL# £51-47
STARTED 4/ 4/54 3:30
NITROGEN
COMPLETED 4/ 4/84 12:55
£ WEIGHT:
ADSORPTION ISOTHERM
5.0730 G
150.8245 CC
P/PO
EGUILISRATICN INTERVAL: 20 SECS
MAX VOL INCREMENT: ico.ooo CC/G STF
VOL ADSORBED
(CC/G AT STP)
0.052S
0.0789
0.1200
0.1 539
0.2001
0.3E57
1.0310
1.1083
1.1757
1.2371
"ROMERITICS INSTRUMENT CORPORATION
DIGISOR3 2600 V2.02
101
TA3E 2
SOUTHWEST RSCH, 002-B, «AL# 851-47
STATION 2
STARTED 4/ 4/84 8130
NITROGEN
COMPLETED''. 4/ 4/84 12:53
SPECIFIC SURFACE AREA
BET SURFACE AREA:
SLOPE:
INTERCEPT:
c:
VM:
4.4178 +/-
O.S7864S +/-
~ 0.00573S +/-
171.'7993
1.0148 CC
0.0165 SQ M/G
0.003652
0.000487
RELATIVE PRESSURE RANGE: 0.0500 TO 0.2100
C-3
-------
ICS INSTRUMENT CORPORATION
DI31SD.73 2300 V2.02 PAG"
101
;'JTH«'ECT RESEARCH 004 «AL #082-44 NITROGEN
:ATION 2 STARTED 4/10/94 ic:4a COMPLETED 4/10/34 is: 3
ADSORPTION ISOTHERM
toPLE WEIGHT: 4.5440 G EQUILIBRATION INTERVAL: 20 SECS
?EE SPACE: is2.54i7.cc MAX VOL INCREMENT: 100.000 cc/c STF
P/PO VOL ADSORBED
CCC/G AT STP)
0.054S 1.2SS5
0.0800 1.378S
0.1198 1.4831
0.1538 1.5733
0.1S33 1.6703
MICROMERITiCS INSTRUMENT CORPORATION
DIGISORB 2SOO V2.02 PAGE f
101 .
.'GUTHUEST RESEARCH 004 MAL #882-44 , NITROGEN
STATION 2 STARTED 4/10/84 10U8 ^COMPLETEC 4/10/84 151 3
SPECIFIC SURFACE AREA
BET SURFACE AREA: 5.9878 +/- 0.0032 SQ M/G
SLOPE: o.72i78i +/- 0.001113
INTERCEPT: ^ 0.005234 +/- o.000143
C: 138.8938
WM: 1.3755 cc
RELATIVE PRESSURE RANGE'. 0.0500 TO 0.2100
C-4
-------
ITICS INSTRUMENT CORPORATION
DIGISORB 2BCO V2.G2
PAGE
:UTK*i£ST SSCKr 3-04-1 -A, KAL* 852-48
rATION 3 STARTED 4/ 4/84 8:30
NITROGEN
COMPLETED 4/ 4/B4 13157
LS WEIGHT:
ADSORPTION ISOTHERM
4.7710 G
P/PO
EQUILIBRATION INTERVAL: 20 SECS
;*AX VOL INCREMENT: :oo.ooo CC/G ST?
VOL ADSORBED
-------
MCROrilRITICS INSTRUMENT CORPORATION
DIGISCRE 2SCO V2.02
101
idLTHWEST ,?£CH, 3C4-1-B» MAL# 853-254 NITROGEN
•TATICN 4 STARTED 4/ 4/84 8.'30 COMPLETED 4/ 4/34 14:58
:A,V,?LE WEIGHT!
r3E:i SPACE:
ADSORPTION ISOTHERM
4.3110 3
,-\ «^
».' U
134.267
P/PO
EQUILIBRATION INTERVAL: 20 SECS
MAX VGL INCSEXENT: IOO.OCG cc/a ST?
VOL ADSORBED
(CC/G AT STP)
0.0533
0 . 07SS
0.11S7
0.1 5S7
0.2000
2.9311
2.11S2
3.37BS
3.5S57
3.803S
MICROMERITICS INSTRUMENT CORPORATION
DIGISCRB 2BOO V2.02
101
2CUTHWEST RSCH, 304-1-6, MAL# 853-254 NITROGEN
STATION 4 STARTED 4/ 4/84 8130 COMPLETED 47 4/84 14159
PAGE 2
SPECIFIC SURFACE AREA-
BET SURFACE AREA:
SLOPE:
INTERCEPT:
c:
13.6433 +/-
0.316734 +/-
0.002338 +/-
138.4876
3.1341 CC
0.0177 SQ M/D
0.000411
0.000055
RELATIVE PRESSURE RANGE! 0.0500 TO 0.2100
06
-------
MCROMERITICS INSTRUMENT CORPORATION
DIGISQRE 2GCO V2.02
101
PAGE
-JLTHWEST RSCK, 3Q4-2-A, MAL# 654-255
STATION 5 .STARTED 4/ 4/84 8130
NITROGEN
COMPLETED 4/ 4/84 IS.' 5
WEIGHT:
PACE::
ADSORPTION ISOTHERM
4.2520 G
T5.334C CC
P/PO
EQUILIBRATION INTERVAL: 20 SECS
MAX VOL INCREMENT: 100.000 CC/G STP
VCL ADSORBED
(CC/Q AT STP)
0.054S
'^i i^ *^ O 1?
v • v y *j C
0.11S5
0.15S7
0.1998
2.8971
2.2S05
3.1153
3.32S1
3.5340
I CROMERI TICS INSTRUMENT CORPORATION
DIGISQRB 2600 V2.02
101
PAGE 2
SOUTHWEST RSCH. 304-2-A, 1»,AL# 854-255
TATION 5
STARTED 4/ 4/84 8130
NITROGEN
COMPLETED 4/ 4/84 1ST 5
SPECIFIC SURFACE AREA
BET SURFACE AREA:
SLOPE:
INTERCEPT:
c:
VM:
'.2.7364 +/-
0.338786 +/-
0.003005 +/-
13.7332
2.3258 CC
0.0274 SQ M/G
0.000723
0.000037
RELATIVE PRESSURE RANGE: 0.0500 TO 0.2100
C-7
-------
MCSOftcRITICS INSTRUMENT CORFG3ATICN
DIGISORE 2SOC VI.02
iOi
2GL7;-i,.I2T RSC'ri, 304-2-B. KAL* 355-2-B NITROGEN
STATION 1 STARTED 4/ 4/34 17:47 COMPLETED 4/ 4/34 20:54
' *" iir— rr»u"r*
^c * c i LI n i .
ADSORPTION ISOTHERM
5.074C G
« '•r /> <-\ ^ *n ••• f^ '^
A w> <«<. a J
-------
NICROMERITICS INSTRUMENT CORPORATION
DIGISORB 2SOO V2.02
101
PAGE
'-OUTHWEST RSCK, 307-A, MAL# 866-44
STATION 4 STARTED 4/ 5/84 16:26
COMPLETED
NITROGEN
4/ 6/84 6: 8
WEIGHT:
SPACE:
ADSORPTION ISOTHERM
4.9430 G
254.1124 CC
P/PO
EQUILIBRATION INTERVAL: 20 SECS
MAX VOL INCREMENT: 100.000 CC/G STP
VOL ADSORBED
(CC/G AT STP)
0.0543
0.0300
0.1192
0.1535
0.1988
4.8073
5.155S
5.5845
5 . 3652
6.3316
MICROMERITICS INSTRUMENT CORPORATION
DIGISORB 2600 V2.02
101
oCUTHWEST RSCH, 307-w, MAL#
STATION 4 STARTED 4/ 5/84- 'Ȥ:**
PAGE 2
NITROGEN
618
BET SURFACE AREA
SLOPE:
INTERCEPT:
c:
24.«S84 '
0.188712 *•/
0.001730 t/
110.1035
5.2310 CC
&.0314 SO M/G
0.000260
0.000033
RELATIVE PRESSURE RANGE: 0.0500 TO 0.2100
C-9
-------
2600 V2.C2
_ • f. . . w
EST 3ECH, 307-3, riAi_# .8G7-46
N 1 aTARTcD 4/ S/84 11153
NITROGEN
COMPLETED 4/ 3/84 15:37
ADSORPTION ISOTHERM
-r . ^T'.i '_•!
152.142S CC
P/PC
! »SOA^*'^lv' »»Li^r~i"-«t<»t - •-»,•. ,-**— ^^ /-
1_ 1 SivH I i _il\ . N i C.iTV>-ii- . ._ .• bc.CS
MAX VGL IN-CLEMENT: 100.000 CC/G ST?
VOL ADSOR3ED
(CC/G AT STP)
/^ '% er T"»
0 . C7SS
C.I132
0. 1535
0.2CC2
4.0113
4.3202
4.GB10
5.0094
5.3077
"»'OhcRITICS INSTRUKcNT CORPOHATIJK
DIGISORB 2300 V2.02
101
PAGE 2
STATION 1
STARTCD
BS7-4£
/ s/a4 11:53
COMPLETED 4/ s/84 15:37
SPECIFIC SURFACE AREA
BET SURFACE AREA!
SLOPE:
INTERCEPT:
c:
VM:
19.1663 +/•
0.22506S +/-
0.002063 +/-
110.1095
4.4028 CC
0.0448 SQ M/Q
O.O0052B
0.000070
RELATIVE PRESSURE RANGE: 0.0500 TO 0.2100
C-10
-------
ITICS INSTRUMENT CORPORATION
DIGlSuRS 2SOC V'2.02
101
37ATICK 2
•2CH, 20E-A, rtALtf 358-47
STARTED 4/ S/84 11153
COMPLETED 4/ S/84 16132
E HEIGHT:
SPACE:
ADSORPTION ISOTHERM
4.8500 0
51.0773 CC
P/PC
EQUILIBRATION INTERVAL'.
MAX VSL INCREMENT: ic
VOL. rt.u
(CC/Q AT STP)
20 SECS
c CC/G STF
0.0540
0.0733
0.1138
0.1538
0.2002
1.S573
1 .7818
1.3020
2.0243
2.1353
INSTRUMENT CORPORATION
DIGI SORB 2SOC V2.02
101
SC'JTHUEST RSCH, 30S-A, KAL# 8S8-47 NITRC3EN
STATION 2 STARTED 4/ S/84 li:53 COMPLETED 4/ S/94 1BI22
SPECIFIC SURFACE AREA
BET SURFACE AREA!
SLOPE:
INTERCEPT:
c:
7.6527 •*-/•
0.5S4935 +/•
0.003903 +/-
145.5101
1.7580 CC
0.0213 SQ M/G
0.001571
0.000210
RELATIVE PRESSURE *A,%GE: O.CSOO TG 0.2100
C-ll
-------
MICRCMER:TICS INSTRUMENT CGRPCRATIGN
DIGIS2RB 2BOO V2.C2 r-A32
^ n 4
J. V .1
.-.uTHWE" 3SC;-:, 3CS-E. XAL# BSS-^2 . ' NITROGEN
TATIGN 2 STARTED 4/ S/G4 11153 COMPLETED 4/ 3/B4 17129
ADSORPTION ISOTHERM
AMP'.E WEIGHT: 4.S380 o SGUILIBRATION INTERVAL: 20 SECS
'•:i=. SPACE: 154.4223 cc MAX VGL INCREMENT: 100.000 CC/G STP
P/PO VOL ADSORBED
(CC/G AT STP)
0.054B
C.073S
0. 1137
0.15S4
C.1SSS
1.1 £39
1.2417
1.2355
1.4244
1.43S7
INSTRUMENT CORPORATION
DIQISORB 2SOO V2.02 PAGE 2
101
30UTHWEST RSCH, 309-B, MAL# 869-48 NITROGEN
STATION 3 STARTED 4/ 6/04 11IS3 COMPLETED 4/ B/B4 17:29
SPECIFIC SURFACE AREA
BET SURFACE AREA: 5.3861 +/- 0.0219 SQ M/G
SLOPE: 0.802473 +/- 0.003252
INTERCEPT: o.005751.+/- 0.000435
C: - 1.40.5249
VM: 1.2373 cc
RELATIVE PRESSURE RANGE: 0.0500 TO 0.2100
C-12
-------
3 10-1 -A,
.* 2SC-2E5
NITROGEN
COMPLETED 4/H/B4 20:57
SPECIFIC SURFACE AREA
BET SURFACE AREA:
SLQFE:
INTERCEPT:
18.177E +/
0.237613 +/
O.OOISB3 +/
0.044E S3 M/G
0.000585
C.000073
4.1757 CC
RELATIVE PRESSURE RANGE: 0.0500 TO 0.2100
MICROMERITICS INSTRUMENT.CORPORATION
DIGISORB 2600 M2.O?.
J01
PAGE
3TAT1SN 2
31C-1-A, KAL# 880-2B5
3TAf
-------
DIGISGR3 ZSOO VZ.CZ
101
RS"Hr 31C-1-S, tfAL# 879-2S4
STARTED 4/11/84 15:33 COMPLETED 4/11/84 13:37
ADSORPTION ISOTHERM
WEIGHT: 5.0350 G EQUILIBRATION INTERVAL: 20 SECS
,r;?ii£ SPACE: i?i.SB77 cc MAX VOL INCREMENT: 100.000 CC/G STP
P/PO VOL ADSORBED
(CC/G AT STP)
0.053B
o.oeoo
0.1194
0.1597
0.2002
3.7117
3.9809
4.3012
4.5873
4.8538
MICROMERITICS INSTRUMENT CORPORATION
DIGISORB 2GOO V2.02 PAGE f
101
-CuTHWEET RSCH, 310-1-Br MAL# 87S-264 . NITROGEN
STATION 1 STARTED 4/11/84 15:33 COMPLETED 4/11/84 13:37
SPECIFIC SURFACE ARFA
BET SURFACE AREA.' 17.4618 */- 0.03G2 SQ M/G
SLOPE: o.247286.+/- 0.000512
INTERCEPT: 0.002013 +/-' o.oo'joss
C: 123.8594
"M: . 4.0113 cc :
RELATIVE PRESSURE RANGE: 0.0500 TO 0.2100
014
-------
RSCHr 310-2-A, «AL# 87S-2SB NITROGEN
STARTED 4/ 3/84 BC S COMPLETED 4/10/84 4.'35
ADSORPTION ISOTHERM
.., . ;• >,£.3HT: 5.17SO G EiililLIBRATIGN It4T£RVAL: 20 3ECS
"" -- — --; 153.572^ CC MAX VOL INCREMENT: 1GO.GOG CC/G STP
P/PO VOL ADSORBED
(CC/G AT STP)
0 . 0543
0.0787
0.1135
0.1597
0.2003
3.4327
3.6533
3.SB23
4.2238
4.4B66
MICRQKERITICS INSTRUMENT CORPORATION
DIGISCRB 2SOO V2.02 PAGE 2
101
T RSCK, 2iO-2-A, MAL# S7S-25E . NITRCGEN
5 STARTED 4/ 9/84 8: 6 . COMPLETED 4/10/84 4135
SPECIFIC SURFACE AREA
BET SURFACE AREA! '16.0555. »•/- 0.0356 SQ M/G
SLOPE: O.ZBBOIO +/- o.ooosas
INTERCEPT: 0.002125 +/- o, 000073
C: 127.5810
UM: 3.6882 CC
RELATIVE PRESSURE RANGE: 0.0500 TO 0..2100
C-15
-------
,'•'• " C^Ortc.'t 7"!" ICS INSTRUMENT C
'>.'
iMKi_-.r SO 1— -1OO i< A ' • ^'-n-l>
STARTED 4/11/84 15:32 COMPLETED 4/li/S4 22:10
WEIGHT:
SPACE:
AD SDR ?T ION I
5.07*0 o
153.4321 cc
P/PO
EQUILIBRATION INTERVAL: 20 SECS
MAX MOL INCREMENT: 100.000 cc/o STP
VOL ADSC.78ED
-------
-A, KAL# E7C-25C
rA^TID 4/ S/S4 11133
NITRQ3EN'
COMPLETED 4/ 6/S4 1SI25
ADSG^PTIQN ISOTHERM
. w O . „ i .. '.» U 4.
iZa'u ILI£f?AT ICN INTERVAL I 20 3EC3
V* ^L*' i i ^» V\*^O ^ *vf ^ v -P* • * ,^ ^ /\ .% i% r^ ^ » « •«" ^ ^»
"ft,-, vuk- j.NoiTwr!eN i . iOs.-.OvO uC/ u air
r/PC
VOL AD£Ci?BED
-------
^3?t FCit ATICr\
»"*, C *. W V '-' V *i • L' te
1C:;
NITROGEN
i:52 CCMPLSTED */ B/S4 18:13
ADSCRPTI3N ISOTHERM
•:..::2;: G ESUILISRATICN I^TESVAL: iv sees
15I.2S77 CC ^AX VCL INCREMENT: 10-0.000 CC/G £'
P/PO VGL ADSORBED
(CC/G AT STP)
C.CS4B
0 . 07S7
0 . 1 1 9E
0.1 5SS
0.133S
1 . i 73i
1.2537
1.3595
1.4527
1.5334
INSTRUMENT CORPORATION
DIGISOr?S 230C V2.02 PAGE -
312-s, MAL# 871-255 NITROGEN
STARTED 4/ B/E4 1K53 COMPLETED 4/ 6/84 13: 13
SPECITIC SURFACE AREA
SET SURFACE AREA: 5.5139 •«•/- 0.0175 SG M/G
SLOPE: 0.782325 +/- 0. 002483
INTERCEPT: O.OOS307 +/- 0.000332
C: 125.0492
VK: 1.2680 cc
RELATIVE PRESSURE RANGE: C.05.00 TO 0.2100
C-18
-------
^IT!CS INSTRUMENT CORPORATISM
•>IGIS3R£ 230;: -.'2.02 PAGE
.-A, «AL# 856-2S5 NITRCGEN
STAr.TEC- 4/ 4/34 17:4-7 COMPLETED 4/ 4/84 22'. S
ADSORPTION ISOTHERM
G IGUILISRATIutt IMTE3VAL: 20 SECS
cc MAX VOL INCREMENT: icc.coo CC/G STF
P/FO VCL ADSORBED
(CC/G AT STP)
C . 053E
0.0 736
c. iisi
0.1534
0.2000
3. 3917
4.1738
4.5141
4.8244
5.1109
' "ROhESITICS INSTRUMENT CORPORATION
DIGISOR3 2BOO V2.02 PAGE 2
101
1-A, «AL# E5S-2S5 NITRCGEM
STARTED 4/ 4/84 17:47 COMPLETED 4/ 4/84 221 3
SPECIFIC SURFACE AREA '
. .,
SET SURFACE AREA: IB. 4213 +/- :6;O382 SO M/G
SLOPE: 0.234284 /+/- 0;000486
INTERCEPT: 0.002030 +/- o.ooooes
C: 118.4289
t.-'M: 4,2317 CC
RELATIVE PRESSURE RANGE: 0.0500 TO 0.2100 .
C-19
-------
r-,:t:RDiv.ERiT:cs INSTRUMENT CORPORATION.
DIGI5.3S2 2300 V2.C2
f i*.Ai_# 857-235 NITROGEN
RTED 4/ 4/84 17:47 COMPLETED */ ^/s« 23:35
ADSORPTION ISOTHERM
3.i.2SO C?. SSUILIBRATICN INTERVAL: 20 SECS
. 44oo cc MAX UCL INCREMENT: ico.coo CC/G STF
11 /PO VOL ADSORBED
(CC/G AT STP)
0.0547
0.0736
0.11SB
0.1 5S5
0.2003
5.0SS7
5.449G
5.8996
6.3072
6.6735
M"C?0«ERITICS INSTRUMENT CORPORATION
DIGISORB 2600 V2.02 pAGE -,
101
-;:^C = ~ Rrr:-:, 3-"-:-B, ^AL# 857-266 NITROGEN
V.r:ON 2 STARTED 4/ 4/84 17:47 COMPLETED 4/ 4/84 23:35
SPECIFIC SURFACE AREA
BET SURFACE AREA.' 24.0838 +/- 0.0561 SQ M/Q
SLOPE: 0.179184 t/- O.OO0417
INTERCEPT: o.ooises +/- o.oooose
C: 115.2632.
V«: 5.5324 CC
RELATIVE PRCSSURE RANGE! 0.0500 TG 0.2100
C-20
-------
CDJ micromeritics*
Liquid Chromatography Instruments/Particle Technology Instruments
April 11, 1984
Mr. Robert E. Panick
Southwest Research Institute
6220 Culebra
San Antonio, Texas 78284
Reference: Your Purchase Order #29318
Micromeritica' File #110723-044-MSP
Your Purchase Order #30660
Micromeritics' File #110605-034-MSP
Dear Mr. Fanick:
The Materials Analysis Laboratory has analyzed your samples on our Digi-
Sorb 2600. Enclosed are data sheets of the results.
Summary of the results:
Sample
Identification
Monolith Catalyst
P.O. #29318
#1
n
#3
#4
#5
#6
P.O.
fl
#2
#3
#4
#5
#6
#7
* #8
312-A
312-B
307-A
307-B
309-A
309-B
#30660
941-A
941-B
002-A
002-B
304-1-A
304-1-B
304-2-A
304-2-B
Specific Surface Area
(m2/g)
1.5
5.5
22.9
19.2
7.7
5.4
18.4
24.1
9.6
4.4
10.3
13.6
12.7
4.4
If you have questions, or if we can better serve you, please contact us.
Sincerely,
Pat McCann, Manager
Materials Analysis
Represented by:
Richard Geary
6907 Leandra Drive
Houston, Texas 77083
INSTRUMENT CORPORATION
5680 Goahen Springs Road • Norcroas. Georgia 30093 USA Telephone (404) 448-8282 • International Telex: 682 7018
-------
OBI micromeritics*
Liquid Chromatography Instruments/Particle Technology Instalments
April 17, 1984
Mr. Robert F. Fanick
Southwest Research Institute
6220 Culebra
San Antonio, TX 78284
Reference: Your Purchase Order #30664
Micromeritics1 File //110722-044-MSP
Dear Mr. Fanick:
The Materials Analysis Laboratory has analyzed your samples on our Digi-
Sorb 2600. Enclosed are data sheets of the results.
Summary of the results:
Sample Specific Surface Area
Identification _ (m2/g) _
Monolith Catalyst
310-1-A 18.2
310- 1-B 17.5
310-2-A 16.1
310-2-B 16.1
004 6.0
If you have questions, or if we can better serve you, please contact us.
Sincerely, Represented by:
v, v vC\ ( Richard Geary
,.\ v\,-.\.., -------
6907 Leandra Drlve
Pat McCann, Manager Houston, TX 77083
Materials Analysis Laboratory (713) 784-1148
P.S. Completing the enclosed Sample Submission Form will simplify our pro-
cedures and will result in decreasing the overall turnaround time of
your samples. We appreciate your returning the completed form with
your samples.
MICROMERITICS INSTRUMENT CORPORATION
6680 Goahen Springs Road » Norcroas, Georgia 30093 USA Telephone (404) 448-8282 • International Tetex: 662 701 a"
'C-22"
-------
APPENDIX D
ELEMENTAL ANALYSIS BY X-RAY FLUORESCENCE
-------
I- S
122SS
Figure D-l. Elemental analysis of catalyst 002-A
;:DA t-'u^ —o
11.02 KEV
Figure D-2. Elemental analysis of catalyst 002-B
D-2
-------
3X 004
1.28
11,02 KEV.
Figure D-3. Elemental analysis of catalyst 004
D-3
-------
3X 304-1-A
1.28 - 11.02 KEV.
Figure D-4. Elemental analysis of catalyst 304-1-A
3X 304-1-B
1.28 - 11.02 KEV.
Al
Figure D-5. Elemental analysis of catalyst 304-1-B
D-4
-------
BX 304-2-A
1.28 - 11.02 KEV.
FS
122S*
Figure D-6. Elemental analysis of catalyst 304-2-A
11.02 KEV
I- 'i
122*8
Figure D-7. Elemental analysis of catalyst 304-2-B
D-5
-------
3A 307—A
1.28 - 11.02 KEV.
F8
122*8
Figure D-8. Elemental analysis of catalyst 307-A
hi X o
1 . 28
- 11.02 KEV.
I- '-:
O £ 3 7
Pi.
Figure D-9. Elemental analysis of catalyst 307-B
D-6
-------
)2 KEV
pC;
1223S
OO3£
—•*
O £ '3 7
Figure D-10. Elemental analysis of catalyst 309-A
Figure D'-ll. Elemental analysis of catalyst 309-B
D-7
-------
FS
122::"?
1.28 - 11.02 KEV
Figure D-12. Elemental analysis of catalyst 310-1-A
Figure D-13. Elemental analysis of catalyst 310-1-B
D-8
-------
F :-:
122:38
Figure D-14. Elemental analysis of catalyst 310-2-A
"O
11.02 KEV
h S
U O 3 cj
";i
o £ s>
Figure D-15. Elemental analysis of catalyst 310-2-B
D-9
-------
,•••% \ / —r .1 /-> f\
o A -jJ. ^~i-i
1.28 -11.02 KEV
F'S
Figure D-16. Elemental analysis of catalyst 312-A
Six 312;--Ei
1.28 - 11.02 KEV.
F'S
1-". -". .-i i"i
iii. OO
Figure D-17. Elemental analysis of catalyst 312-B
D-10
-------
SX 941-
1.28
11.02 KEV.
FS
12283
Figure D-18. Elemental analysis of catalyst 941-A
f". \. f\ -'I -t T"
O A 7 4 1 — b
1.26 - 11.02 KEV.
FS
O O 3 £
O Z S"7
Figure D-19. Elemental analysis of catalyst 941-B
D-ll
-------
APPENDIX E
MICROGRAPHS FROM SCANNING ELECTRON MICROSCOPE
-------
Figure E-l. Micrograph of 002-A (500X)
Figure E-2. Microgrpah of 002-B (500X)
E-2
-------
Figure E-3. Micrograph of 004 (500X)
E-3
-------
Figure E-4. Micrograph of 304-1-A (500X)
Figure E-5. Micrograph of
E-4
-------
Figure E-6. Micrograph of 304-2-A (500X)
Figure E-7. Micrograph of 304-2-B (500X)
E-5
-------
Figure E-8. Micrograph of 307-A (500X)
Figure E-9. Micrograph of 307-B (500X)
E-6
-------
Figure E-10. Micrograph of 309-A (500X)
Figure E-ll. Micrograph of 309-B (500X)
E-7
-------
Figure E-12. Micrograph of 310-1-A (500X)
Figure E-13. Micrograph of 310-1-B (500X)
-------
Figure E-14. Micrograph of 310-2-A (500X)
Figure E-15. Micrograph of 310-2-B (500X)
E-9
-------
"IP*-" ^«i^V»«-Jfc
v* *** > - *.%^-*T
a^SS "v
•^rygtocis,
«»•»••
^u^
Figure E-16. Micrograph of 312-A (500X)
Figure E-17. Micrograph of 312-B (500X)
E-10
-------
Figure E-18. Micrograph of 941-A (500X)
Figure E-19. Micrograph of 941-B (500X)
E-ll
-------
TECHNICAL REPORT DATA
(Please read Inunctions on the reverse before completing)
1. REPORT NO. 2.
EPA 460/3-84-007
4. TITLE AND SUBTITLE
Lead-Poisoned Catalyst Evaluation
7. AUTHOR(S)
E. Robert Fanick
Melvin N. Ingalls
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Southwest Research Institute
Department of Emissions Research
6220 Culebra Road
San Antonio. Texas 78284
12. SPONSORING AGENCY NAME AND ADDRESS
Environmental Protection Agency
2565 Plymouth Road
Ann Arbor, Michigan 48105
15. SUPPLEMENTARY NOTES
3. RECIPIENT'S ACCESSION-NO.
6. REPORT DATE
August 1985
6. PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION REPORT NO.
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-03-3162
13. TYPE OF REPORT AND PERIOD COVERED
Final (Feb. 1984 - June 1984
14. SPONSORING AGENCY CODE
16. ABSTRACT
Ten catalyst from eight vehicles representing four vehicle manufacturers
were examined using several physical and chemical procedures for poison accumu-
lation, overheating, plugging, thermal deterioration, and noble metal loss.
The analysis of each converter consisted of visual inspection, whole converter
radiographs BET surface area, elemental analysis, and scanning electron micro-
scope examination of surface. Correlations between the "on-vehicle" emissions
and the analytical results were conducted.
17. KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS b.lDENTIF
Air Pollution Catal
Exhaust Emissions inten
Motor Vehicles catal
poise
catal
18. DISTRIBUTION STATEMENT ' ' 19. SECUR
Ilnr' la
Release Unlimited 20.secuR
Uncla
ERS/OPEN ENDED TERMS C. COSATI Field/GlOUp
yst, lead poisoned
itionally leaded
yst, leaded fuel,
>n accumulation
yst deterioration
T Y CLASS (This Report) 21 . NO. OF PAGES
3-sHf-fpH 115
TY CLASS (This page) 22. PRICE
ssif ied
EPA Form 2220-1 (B-73)
------- |