本田財団レポート №102
第２３回本田賞授与式 記念講演（2002 年 11 月 15 日）

自動車排気の触媒による浄化
ジョンソン・マッセイ社
カタリティック・システムズ部門 副社長

バリー J. クーパー博士

The Catalytic Control of Motor Vehicle Emissions
Commemorative Lecture at the Twenty-Third Honda Prize Awarding
Ceremony on the 15th November 2002 in Tokyo

Doctor Barry J.Cooper
Vice President,Catalytic Systems Division
Johson Matthey

財団法人

本田財団

バリー J. クーパー博士
ジョンソン・マッセイ社
カタリティック・システムズ部門 副社長

Barry John Cooper
Vice President, Catalytic Systems Division
Johson Matthey■略歴1942 年
1964 年
1966 年
1976 年
1964〜77 年
1977〜79 年
1979 年〜現在

英国 ベッドフォードシャー州ルートンで生まれる
ルートン・カレッジ・オブ・テクノロジーでＢ
Ｓ学士号を取得
インペリアル・カレッジ化学技術工学部で修士号取得
ロンドン大学で博士号取得
ジョンソン・マッセイＰＬＣテクノロジー・センター（英国）に勤務
トロンドハイム大学応用化学部付属 SINTEF 研究所（ノルウェー）に勤務
ジョンソン・マッセイ INC（米国）に勤務
主任サイエンティスト、開発マネジャー、技術部長、技術担当副社長を経て、現在、Diesel
Emission Control System 担当副社長■受賞歴：
1980 年
自動車排気制御用３元触媒の開発により、Fellowshipof Engineering（現王立工学アカデミー）の MacRobertAward を受賞（英）1990 年
SAE(Society of Automotive Engineering)技術文献への顕著な貢献を認められ、同会の Arch T. Colwell 功
労賞を受賞（米）1992 年
SAE フェローに選出（米）1994 年
先進の自動車排気制御用３元触媒の開発により、
Honda Supplier Award for Technology Developmentを開発チームリーダーとして受賞
2000 年
貴金属科学への顕著な貢献により、International
Precious Metals Institute から Henry J. Albert メダルを受賞（米）2000 年
CRT（連続再生式トラップ）方式のディーゼル有害微粒子除去システムの発明・開発に対して、二度目のMacRobert Award を受賞（英）2000 年
自動車排気制御の先進技術に対して、Manufacturersof Emission Control Association から特別功労賞を受賞（米）2001 年
ガソリンエンジン排気制御委員会議長としての功績に対して,特別功労賞を受賞（米）■Personal History
1942
Born in Luton, Bedfordshire, England
1964
B.Sc. in Luton College of Technology, England
1966
Diploma of Imperial College in Chemical
Engineering at Imperial College, London
1976
Ph.D. at London University
1964-77 Employed in Johnson Matthey Plc., Technology
Center, England
1977-79 Employed in SINTEF, Department of Applied
Chemistry at University of Trondheim, Norway
1979Employed in Johnson Matthey Inc., U.S.A. as
Principal Scientist, Development Manager,
Technical Director, Vice President (Technology),
now Vice President of Diesel Emission Control
Systems■Awards:
1980 The MacRobert Award for the development ofThree-Way Catalysts for Automotive Emission
Control from the Fellowship of Engineering, now theRoyal Academy of Engineering, UK
The Arch T. Colwell Merit Award from the Society ofAutomotive Engineers, USA for outstanding
contribution to SAE technical literature
1992 Elected to SAE Fellow from the Society of Automotive
Engineers
1994 Team Leader for the Honda Supplier Award forTechnology Development for advanced Three-Way
Emission Control Catalysts
2000 The Henry J. Albert Award for significant contribution
to research advancing the use of Precious Metals fromthe International Precious Metal Institute, USA
2000 The MacRobert Award from the Royal Academy ofEngineering, UK. for the development of theContinuously Regenerating Trap for control of Diesel
Particulate Emissions
2000 The Manufacuturers of Emission Control Association
Award for Outstanding Contributions in thedevelopment of Advanced Motor Vehicle Emission
Control Technology
2001 The Special Achievement Award from the
Manufacturers of Emission Control Association inrecognition of Leadership as Chairman of the Gasoline
Engine Emission Control Committee

The Catalytic Control of Motor Vehicle Emissions

Commemorative Lecture at the Twenty-Third Honda Prize Awarding
Ceremony on the 15th November 2002 in Tokyo

Doctor Barry J.Cooper
Vice President,Catalytic Systems Division
Johson Matthey

30

Good Evening ladies and gentlemen.
Minasama Konnichiwa
I am here this evening as the proud recipient of the Honda Prize to tell you about thecontributions I have made to the development of Catalytic Convertors - those magic boxesin the exhaust pipe of your car that have done so much to make the air cleaner for us all.
But first I would like to start by acknowledging key people who have brought me here thisevening
My sincere thanks go of course to the Honda Foundation for electing me as this year’s
prizewinner and to Mr. Kawashima for his kind welcome to my wife and I.
I would also like to personally thank staves for their kind support in preparing me for the
prize ceremony.
I would like to thank the Directors of Johnson Matthey and I would also like to recognize
particular colleagues at Johnson Matthey with who I have worked with in my 30 years ofdeveloping catalytic emission control systems.
They are Gary Acres, Brian Cooper, David Evans and Dennis Webster who started Johnson
Matthey’s first program in catalytic emission control for motor vehicles in 1970. I would
also like to acknowledge Jim Thoss, Pelham Hawker and Par Jones They were mycolleagues in the development and commercialization of our Continuously Regenerating
Trap system for control of diesel particulate emissions in the 1990’s.
I indebted to Sir Alec Broers and Britain’s Royal Academy of Engineering for nominating
me for this prize.
Particular thanks go to Mr. Tadayoshi Hayashi of Honda and Dr. Hideaki Muraki ofJohnson Matthey who solicited independent letters of support for my nomination from
Professor Misono and Professor Daisho.
Thanks also to my old friend Professor Trimm who is here all the way from Australia. He
welcomed me as a fresh PhD student and taught me what a catalyst is when I was very
very young.

31

触媒コンバータ

Figure 1
My talk today is all about cleaning up the air by removing exhaust emissions from motor
vehicles using catalytic convertors. This is a device that converts harmful gases in theexhaust of your car to clean nitrogen water and carbon dioxide.
If you drive a car ---- you have one of these highly effective devices which are so beneficial to
our environment in the exhaust pipe of your car.
The Honda Company truly follows the advocacy of the Honda Foundation, and its founder,
Mr. Soichiro Honda in developing products that are of benefit to human civilization. These
products are geared towards harmony with both the environment and surrounding humanactivities.

空気をきれいにするホンダエンジン

Figure 2

32

The Honda organization is synonymous with the production of very high quality,
environmentally friendly vehicles. Indeed, the latest vehicles produced by Honda are
powered by engines that are the lowest emitters of pollutant gases in the world. They meetor exceed the most stringent emission legislation in the world.
The ability of motor vehicles today to produce virtually zero exhaust emissions is due to thedevelopment of sophisticated catalysts and engine control systems. This enables over 98%
of exhaust pollutants emitted from the engine to be removed by catalytic means.
But first lets turn the clock back to the 1960s…….
In the 1960’s a vehicle without any emission control devices would emit over 100 grams ofpollutant for every mile driven.
This meant that all the motor vehicles in America would emit over over 120 million tonnesof exhaust pollutants every year. That is equal to 14 tonnes of pollution over every square
kilometer of land area.
Fortunately, today exhaust emissions are much lower as a result of technological advancesand government enforced regulations. Today’s emission levels are 98% lower at just over 2
million tonnes or 0.3 tonnes per square kilometer.

Emission Standards
排気規制値

United States (g/mile)
Year

HC

CO

NOx

Pre-Control

9

90

3.1

1.50
1.5
0.41
0.41
0.25
0.25
0.125
0.075
0.04
0.04
0.01

15
15
7
3.4
3.4
3.4
3.4
3.4
1.7
1.7
1.0

3.1
2
2
1
0.4
0.4
0.4
0.2
0.2
0.5
0.02

1975
1977
1980
1981-U.S.
1994-U.S.
1993-Calif
1994-TLEV
1997-TLEV
1997-2003 ULEV
2004 ULEV2
2004 SULEV2

Japan (g/Km)
CO
max

Year

HC
m ax

mean

NOx
m ax

m ean

m ean

1976

2. 7

2.1

0.39

0.25

0. 84

0.6

1991

2. 7

2.1

0.39

0.25

0. 48

0.25

2002

1.27

0.67

0.17

0.08

0. 17

0.08

Figure 333This slide shows how emission legislation has moved from 1975 through to today for theUnited States and Japan.
Vehicles are now capable of meeting these stringent standards. And Catalytic Convertors
are the reason they do.
My purpose here tonight you how I was involved in making this happen.
My role in this story started in the Johnson Matthey Laboratories in 1970.
So welcome to my story…….

Figure 4
Actually the tale begins in the 1950’s when Photo-chemical smog - the brown haze we see inthe air - was becoming a persistent problem in the Los Angeles basin. It was also later seenin Tokyo and other large cities.
Research by Professor Haagen-Smit in California showed that the smog was due to areaction between nitrogen oxides and hydrocarbons in the air.
Measurements showed that cars were responsible for 70% of the hydrocarbon emissions and
60% of the nitrogen oxide emissions in the air.
These observations were responsible for the strict legislation to control emissions frommotor vehicles. Legislation to control these emissions occurred at almost the same time in
the United States in 1975, and in Japan in 1976.

34

The severity of this new legislation required a new approach to the control of emissions.
Catalytic devices were shown to have great promise in the race to lower emissions.
The challenges to make catalytic convertors work were formidable. My presentation aims toshow you how some of the key challenges were overcome. And how work in the Johnson
Matthey laboratories has made a significant contribution to this challenge.
So how do Catalytic Convertors work?
To understand this lets look at what a catalyst is,
Lets look inside the convertor
and lets look at the chemical reactions that occur over a catalyst….

The classic definition of a catalyst is a substance that can speed up a chemical reaction
withoutt itself being used up.
withouIn exhaust emission control, we remove pollutants by a chemical reaction on a solid catalyst
surface.
The path of the reaction is altered by the presence of the catalytic surface. This happens by
the formation of surface chemicalchemical compounds - the pollutants stick to the surface and react.
Now let us look inside the catalytic convertor and find out more about this catalyst…….

Catalytic Convertor H2O
触媒コンバータ

CO2
N2

Catalyst
触媒

HC
CO

NOx

Figure 535Here we see a picture of a catalytic convertor in the upper left of the slide. You can clearlysee how the catalyst is contained inside the steel can of the catalytic convertor.
Microscope pictures inside the catalyst are shown on the right.
The top right picture shows the channels through which the exhaust gas flows.
The middle picture shows the particles of catalyst coated on the channel walls.
The bottom right picture shows a high magnification picture of the crystallites inside theseparticles.
The catalytic coating contains platinum group metals. These are typically platinum,
palladium or rhodium. These metals drive the catalytic process, and the reactions takeplace on the surface of tiny metal crystals in the catalyst coating.
Later we will explore this micro structural world and lookat catalyst design.

But first what are the catalytic reactions??? Let us look at some chemistry…….

Emission Control Reactions
排気浄化反応Pollutants:
汚染物質：

Carbon Monoxide CO
一酸化炭素

Hydrocarbon HC
炭化水素

Nitrogen Oxide NO
窒素酸化物

Oxidation

Reduction

酸化反応

還元反応

2CO + O2

2CO2

2NO +2CO

2CO2 + N2

HC +O2CO2 + H2O

NO + HC

CO2 + H2O + N2

Figure 6
Emission control reactions are really quite simple. They can be divided into oxidation
reactions and reduction reactions.
The pollutants from a gasoline engine are the poisonous gas carbon monoxide together withhydrocarbons from unburnt fuel.These are formed by incomplete combustion of gasoline.

36

In addition a third pollutant nitrogen oxide is also formed from nitrogen and oxygen athigh temperature in the combustion chamber of the engine.
The reactions that occur under oxidizing conditions are the reaction of carbon monoxidewith oxygen to produce carbon dioxide, and the reaction of hydrocarbon with oxygen to
produce carbon dioxide and water.
Nitrogen Oxide is removed by a reduction reaction with carbon monoxide and hydrocarbon
to produce nitrogen.
Having looked at what a cataytic convertor is, and how it works, lets go back to the 1970s
and the first experiments
In 1970 the big problem for a catalytic convertor was the high emissions that occur when acar is started from cold. The catalyst needs to reach its operating temperature or so-called
light-off temperature before it starts to work.

浄化率(%)
浄化率(%)

酸化触媒の昇温特性

Loff vs Base Metal

白金触媒
改良白金
触媒

卑金属触媒

温度（℃）

Figure 7
Our first experiments focused on lowering the light-off temperature of the catalyst so thatthe catalyst would work better under cold conditions.
This slide duplicates some of the early test results reported in our first research report on
design of catalysts for exhaust emission control. The vertical axis shows conversion, and thehorizontal axis is temperature.

37

The results show that a platinum catalyst has a lower light-off temperature than a basemetal catalyst.
However, we discovered that we could lower the platinum catalyst light-off temperature
further by promoting the platinum catalyst by other platinum group metals,

The promoted catalyst was also found to be very effective for controlling nitrogen oxide
emissions.
The promoted catalyst used rhodium in addition to platinum.
米国特許

Figure 8
The discovery was filed as a patent in November 1971, and the patent was granted in April
1976 as US Patent number 3,951,860
The catalyst was subsequently tested on a vehicle according to the new 1970 US Test
procedure. This test was difficult to pass as it incorporated a cold start, and so it was areal challenge for the new catalyst system.
So what is this test…….
The US vehicle emission test was developed in the early 1970’s based on driving in the Los
Angeles area.

38

Transient test cycles were developed to get realistic vehicle emission measurements basedon driving patterns around Los Angeles
US Test Procedure (FTP)(Phases 1 and 2)
米国排気測定走行モード
8070

車速(mile/hr)

60
50
40
30
20
10
0
0

100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400

時間（秒）Figure 9
The US test procedure is shown in this slide, where vehicle speed is plotted against time of
the test. A vehicle must be driven following this speed trace while emissions are collectedfrom the exhaust of the car.
Similar, but not identical, tests are now in place in Japan and in Europe.
The test is carried out by placing a vehicle on a dynamometer. The vehicle is driven while
following the speed trace on a monitor placed alongside the vehicle.
First Johnson Matthey Test Car
最初のジョンソン・マッセイの実験車輌

Figure 1039This historic slide from the 1970’s shows Johnson Matthey’s first test car undergoing tests
with the new platinum/rhodium catalyst in our laboratory in Royston, England.
After developing the platinum/rhodium catalyst Johnson Matthey contracted RicardoEngineering in England to carry out a 25,000 mile (40,000km) durability trial.
Johnson Matthey’s First Durability Test Vehicle
ジョンソン・マッセイの最初の耐久実験車輌

Figure 11
The car we used was a Chrysler Avenger and is shown in this slide.
Johnson Matthey,s successful 25,000-mile demonstration of the platinum/rhodium catalytic
catalytic converter in 1972 was highly acclaimed. It proved it was possible pass the level ofemissions in the new US 1970 Clean Air Act.
The results were presented at a hearing held by the United States Environmental
Protection Agency. The landmark results were widely reported as shown by the headlines
from British newspapers at that time.
At the same time our attention was focussing on high volume manufacture of monolithcatalysts for catalytic convertors. This, in itself, proved to be a substantial technicalchallenge.
The task was to coat ceramic monoliths containing a hundreds of small parallel channels
with high surface area catalytic materials efficiently and reproducibly.

40Washcoating Monolith Supports
モノリス担体への触媒担持

Figure 12
The technique adopted by Johnson Matthey was to washcoat the catalytic materials onto
monoliths using a waterfall technique. Here we see a ceramic monolith passing throughthe waterfall of catalyst material. Some really clever chemistry was required control theproperties of the coating during the process - but we will not go into that here.
The manufacturing process was successfully developed and entered into production in 1974
at Royston in the United Kingdom and Wayne, Pennsylvania in the United States.
Today Johnson Matthey has 9 production plants around the world producing emission
control catalysts.
Catalytic convertor systems continued to develop rapidly over the next five years…….
Conventional Oxidation Catalyst (COC)
酸化触媒システム
Ca. 1975

Figure 13
In 1975, the car companies adopted the conventional oxidation catalyst.
A single catalyst was used to control carbon monoxide and hydrocarbon emission. An Air
Pump was used to provide air in front of the catalytic converter for the oxidation process.
41

Dual Bed Convertor (DBC)
段触媒システムCa. 1978 2段触媒システム

Figure 14
In 1978, the dual-bed converter was introduced to obtain NOx control in addition to carbon
monoxide and hydrocarbon control. In this case, the engine was tuned rich and a converter
capable of reducing nitrogen oxides was placed in the exhaust stream. This was followed byan air pump and conventional oxidation catalyst.
Three Way Catalyst (TWC)
Ca. 1981
三元触媒システム

Figure 15
In 1981, the modern three-way catalyst came into effective use due to the development a
new technology - the oxygen sensor…... This sensor allowed the engineer to control theengine air fuel ratio very precisely…..
To understand the importance of air fuel ratio control we need to look at how the three-way
catalyst efficiency changes as air fuel ratio changes.

42

CATALYST EFFICIENCY vs.
ENGINE AIR-FUEL RATIO
触媒の浄化率とエンジンの空燃比

浄化率（％）

Conversion

NO

HC
CO

Excess Fuel

STOICHIOMETRIC
AIR-FUEL RATIO

燃料過剰

理論空燃比

Excess Air
空気過剰

Figure 16
This slide shows how the efficiency of three-way catalysts depends on control of air fuelratio into the engine. The vertical axis is conversion and the horizontal axis is air fuel ratio.
Optimum efficiency occurs where air and fuel into the engine are chemically balanced -theso called stoichiometric air fuel ratio. You can see at this point the catalyst efficiency is very
high for conversion of all three pollutants.
So if you control Air/Fuel into the engine the catalytic convertor works a lot better……..
Early Oxygen sensor
初期の酸素センサー

Figure 17
The device that made Air/Fuel control possible was the oxygen sensor. An early oxygen
sensor is shown in this slide.

43

The oxygen sensor is capable of detecting oxygen in the exhaust……..
When the Air Fuel ratio is rich oxygen in the exhaust is low. When it is lean oxygen is high.
The oxygen sensor is placed in the exhaust stream ahead of the three-way converter. It
detects the change in oxygen concentration across the stoichiometric by a change inelectrical potential from the oxygen sensor. Therefore the perfect point for operation of athree way catalyst can be found.
Now the race was on to improve performance at this critical air fuel ratio……...
In the late 1970’s and early 1980’s, three-way catalysts advanced substantially inperformance capability.
Advances were made due to the advent of oxygen storage materials. Under rich conditions
these materials release oxygen to promote Carbon Monoxide oxidation. Under leanconditions they promote nitrogen oxide reduction by storing oxygen.
One such oxygen storage material that is cerium dioxide, CeO2. This can be reduced to thelower valent oxide Ce2O3
Cooper et al. SAE 850128“Operational Criteria Affecting the Design of Three-Way Catalysts

Effect of Ce Promoter on a
Rhodium Three-Way Catalyst
ロジウム系三元触媒に及ぼすセリウムの効果% Conversion

100
90
80
70
60
50
40
30
20
10
0

CO (- Ce)NOX (-Ce)
CO (+Ce)NOX (+Ce)

0.96

0.97

0.98

0.99
1.00 1.01
Stoichiometric

1.02

1.03

1.04

Point

Air/Fuel Ratio

Figure 18
The effect of cerium promoters was clearly identified in our SAE paper 850128 titled“Operational Criteria Effecting the Design of Three-Way Catalysts”. A graph from thispaper is reproduced here in this slide. It shows the effect of cerium promoter on a threeway catalyst. Again we see a plot of conversion against air/fuel ratio.
44

The simple message here is that the Cerium Dioxide promoted catalyst in green has muchhigher activity for Carbon Monoxide and Nitrogen Oxide conversion than the unpromoted
catalyst in red.
The design of modern three-way catalysts is substantially more complex than catalyst
systems that were tested in the early 1970’s.
These new designs emerged after pioneering work in the Johnson Matthey laboratories led
to a deeper understanding of what happened to multi-metal catalysts such as platinum andrhodium in use.
An excellent example is given in our SAE Paper in 1977. In that paper we reported theanalysis of a severely sintered rhodium/platinum catalyst. Sintering is bad for catalyst

performance as it causes loss of catalyst activity.

Cooper et al SAE 770367

Analysis of Rh/Pt Catalysts
ロジウム/
ロジウム/白金 触媒の解析

Figure 19
In the micrograph on the left you can clearly see the sintered platinum crystallites. But
Energy Dispersive X-ray Analysis on the right revealed that the large sintered crystallites
of metal contained both platinum and rhodium

also
Application of a surface analysis technique called X-Ray Photo Electron Spectroscopy alsorevealed that the rhodium was concentrated at the surface of the platinum crystallite. Also
the rhodium on the surface was oxidized.
It raised the question of whether physical separation of platinum and rhodium would
improve catalyst performance.

45

Trials showed that catalysts where the two metals had been deliberately separated fromeach resulted in lower emissions.
THIS LED TO A WHOLE NEW CONCEPT - STRUCURAL DESIGN OF CATALYSTS……..
Catalyst structural design consisted of making multiple layers of catalysts with platinum
and rhodium in different layers.

Catalyst Structural Design
Combining Optimum Components
触媒構造の設計
最適成分の組み合わせ

Al2O3
Rh/Ce02
Pt/Al2O3
Al2O3

Figure 20
A schematic of such a catalyst is shown in this slide. It represents the corner of a monolithcatalyst cell in which the lower layer of catalytic materials contains platinum and alumina,
and the upper layer contains rhodium on cerium dioxide.
Lets see a microscope picture of this catalyst………..

46

MicroGraph

顕微鏡写真

Pt Distribution

Rh Distribution

Ce Distribution

白金の分布

ロジウムの分布

セリウムの分布

Figure 21
A electron microscope image of such a catalyst is shown in this slide.
The first picture at the top is the electron image showing an intersection of the monolith
substrate walls coated first with a dark coating layer followed by a light-coating layer.
The picture at the bottom left shows the platinum distribution and the bottom middle
picture shows the rhodium distribution. The platinum is clearly distributed in the lower
catalyst layer and the rhodium is distributed in the upper catalyst layer.
The picture at the bottom right shows the cerium dioxide distribution within the catalyst
The cerium dioxide is associated with the rhodium in the upper layer of the catalyst
The structural design target had been achieved! These catalysts came into use in the early

1990’s47

An even more complex example of sophisticated structural design for a tri-metal platinum,
palladium, rhodium catalyst was developed and patented in US Patent number 5,753,580.
This was patented by T. Hayashi and S. Kikuchi of Honda who are with us in the audience
tonight.

Honda Supplier Award
本田技研工業株式会社の優良感謝賞

Figure 22
This Patent was based on joint work with Johnson Matthey and Honda was gracious
enough to award Johnson Matthey the technology award shown in this slide in 1994.
Similar structural designs were used in the early 1990’s in palladium-only catalysts toovercome the limitations of using a single catalytic metal.

Structural Design of Pd only Catalysts
パラジウムだけの触媒設計

Pd/Al2O3
Al2O3
Pd/CeO2

Figure 23
A Schematic of such a catalyst is shown here where the lower layer contains Palladium on
cerium dioxide, and the upper layer contains Palladium on alumina.
48

The use of Palladium was driven by more stringent emission legislation coming from
California with the advent of the Low Emission Vehicle (LEV) regulations.
These regulations placed even more emphasis on cold-start performance and palladium wasfound to be uniquely suited to control hydrocarbon emissions under cold-start conditions.
So how did structural design help??
By use of structural design techniques we were able to obtain better performance of thepalladium catalyst under cold start conditions by lowering the catalyst light off
temperature.

Design Of Pd Catalysts
パラジムの触媒の設計

Light Off Temperature
昇温特性(%)

Conversion at 500 C (%)
500℃の浄化率 (%)

450
430
410
390

(Structured Pd Catalyst(Non Structured Pd Catalyst

100
95
90
85

370

80

350

75

330

70

310

65

290

60

270

55

250
HC

CO

NOx

50
HC

CO

NOx

層構造のパラジウム触媒
均一層のパラジウム触媒

Figure 24
The improvements in light-off temperature are shown in the left graph.
Also we were able to get higher conversion when the catalyst is hot, as shown in the rightgraph.
But these catalysts used a lot of palladium……....

49

パラジウムの値段

年

Figure 25
The use of palladium catalysts at high metal loadings became very common in the mid tolate 1990’s causing a large escalation in palladium price, peaking at the end of 2000.
This resulted in a significant increase in price of the catalytic converter. This was obviously
undesirable to the car manufacturer and to the vehicle buying public.
Significant pressures were placed on reducing the palladium use in catalytic converters toachieve cost-effective performance by substituting part of the palladium with low levels of
platinum and rhodium.

50But this had to be achieved against even tighter emission standards………..
Johnson Matthey has responded to this challenge with new catalyst designs containing
ultra-low levels of platinum group metals.

Ultra-Low PGM System
超低貴金属触媒システム
2000MY System

V8 EngineCCUF

9.7 g Pd

6.7 g
Pd + Rh

CC

UF

Future Ultra-Low PGM System

UFCC
V8 Engine

1.6 g
Pd+ Pt + Rh

0.15 g Rh

UF

CC

Figure 26
An example of such a design is shown in this slide.
This system is designed for a V-8 engine and consists of two close-coupled converters
labeled CC, followed by two under-floor converters labeled UF. This is a typical convertor
configuration for a V8 engine.
Here a 2000 model year system is compared to a future system containing catalysts at ultra
low levels of platinum group metals.
The new system represents an 84% reduction in platinum group metals in the close-coupledconverter and 98% reduction of platinum group metals in the under-floor convertor. This ofcourse results in substantial price reductions available to the customer.
The under floor converters contain less that 100 parts per million Rhodium – a virtually
undetectable amount.
BUT DO THEY WORK???? YES THEY DO!!!!

51

Ultra-Low PGM System beats LEV II after 50,000 mile aging
超低貴金属触媒システムは５万マイル耐久後、LEV-II規制値を凌駕する

HC

NOx

0.0 8

0.06

0.0 7
0.05

NOx (g/mi)

NMHC (g/m i)

0.0 6
0.0 5
0.0 4
0.0 3

0.04
0.03
0.02

0.0 2
0.01

0.0 1
0

0
LE V II
S tan d a rd

Ultra-L ow P GM
SystemLE V II
S ta n d ard

Ultra-L ow P G M
Sys tem

Figure 27
You can see in the yellow bars that tests of the ultra-low platinum group metal system haveshown that it beats the new California LEV2 standard.
It gives less than half the emissions that are allowed even after 50,000 miles aging

Principal Automotive Customers 2000
European

主要な自動車メーカー顧客 2000
North American

Japanese

Ford Group
Ford/Jaguar/AMAL
Ford
Ford/Mercury/Lincoln
VW Group
VW/Audi/SEAT/Skoda
Jeep
DaimlerChrysler
PSA Group
Peugeot/Citroen
Mitsubishi MMMA
ToyotaFiat Group
Fiat/Lancia/Alfa/Ferrari Honda
HAM
Fuji
Volvo Group
Volvo/NedCar/TWR
SuzukiCAMI
Mitsubishi
BMW Group
BMW/Rover/Land Rover Toyota
TABC
Suzuki
PorschePorscheFuji
SIA/Fuji
Mazda
ToyotaToyota-UK
NissanDaihatsu
Honda
Honda-UK
SuzukiMaruti/Magyar
South African
ASEAN
Rolls-Royce
Rolls-Royce/Bentley
MMC
ProtonFord Samcor
Renault
Renault
Honda HCMT
VW
VWSA
Aftermarket
ToyotaFord
South America
BMW PSACar Sound
Daihatsu MMC
Fiat
Ford
Fiat
Rover
Maremont
Renault VW
Daimler/Chrysler
Eastern
Daimler/Chrysler
Bosal
Peasa

Honda

Figure 28
I would now like to conclude this part of the presentation on gasoline vehicle catalysts
before moving on to talk about diesel catalysts.Technology advances such as these haveenabled Johnson Matthey to remain a leader in the market place.

52

Today all the major motor vehicle corporations around the world employ Johnson Matthey
catalysts in their convertor systems.

The new challenge is to develop convertor systems for diesel engines…….

Figure 29
We are all aware of the smoky exhaust of diesel engines and the annoyance it creates in ourcity environments

Diesel engine manufacturers have made substantial strides in reducing the smoke orparticulate emission from the engine through combustion system improvements.
But growing health concerns over diesel particulates have led to strict new legislation.
In the United States both the California Air Resources Board, and the Environmental
Protection Agency have declared Diesel Particulate a toxic substance.
But what is diesel particulate - often also called soot or smoke……..???

53

Schematic of Diesel Particles
ディーゼルパーティキュレートの模式図
Solid Carbon Spheres (0.01- 0.08 mm diameter)
固形炭素粒

Adsorbed Hydrocarbons
吸着炭化水素Liquid Condensed
Hydrocarbon Particles
凝縮液状炭化水素粒
Sulfate with Hydration
サルフェートFigure 30
Diesel particulate consists of a carbon core comprising solid carbon spheres which
agglomerate together to form a particle. These particles contain adsorbed hydrocarbons,
many of which are cancer causing and toxic.
The particulates are small enough to be breathed deep into the lungs where they cause
most damage.

For the past two decades, intense research has been conducted on filter systems, which arecapable of removing these particles from diesel exhaustHigh efficiency filters capable of eliminating 98% of the particulate have been developed.
ウォールフローフィルターFigure 31

54

The most well known of these is the wall flow filter manufactured by NGK in Japan andCorning in the United States.
The filter consists of a ceramic monolith with, alternate cells plugged, forcing the exhaust
flow through the wall. The particulate is trapped on the wall of the filter.
The major problem with filter materials is that they rapidly fill with diesel particulate andbecome clogged. This increases the back pressure across the filter and leads to poor engine
performance and ultimately engine failure.
Therefore, no diesel particulate filtration device can operate without the use of aregeneration system to remove the particulate from the filter.
Prior to 1989 various complicated regeneration methods had been used. These included
such approaches as electrical heaters or diesel fuel burners. Their purpose was to heat thefilter to high temperature and oxidize the carbon particulate.
Think of it like setting light to your charcoal barbecue grill!!
Johnson Matthey’s challenge was to develop a catalytic process for burning diesel
particulate that would operate under the low temperatures found in diesel exhaust.

Cooper-Thoss

SAE 890404
TABLE 4

Effect of Exhaust Components
On Particulate Combustion Rate
排気組成の煤燃焼温度に及ぼす効果

NO2 BURNS SOOT

TEST

N2
Balance

1
2
3
4
5
6
7
8
9
10

9
9
9
9
9
9
9
9
9
9

NO
400 ppm
9
9
9
9
9
9

O2
12%

H20
4.5%

RATE
“H20/hr

9

0
10
32
0
30
64
28
4
0
0

9
9
9
9

9
9

9
9
9

9 Indicates component present

Figure 32
In 1989 we reported a breakthrough in SAE paper 890404.
In that paper, my co-author, Jim Thoss, and I reported that the combustion of diesel
particulate could be reduced to from 600ºC to 250º C by using Nitrogen Dioxide NO2 in theexhaust.

55

The key results are shown in this slide in red. When NO and oxygen were passed over aplatinum catalyst NO2 was formed and the rate of particulate (Soot) burning substantially
increased.
The next challenge was to develop a catalytic convertor to produce NO2 together with afilter system to collect the particulate.

CRTTMでのNO2の反応ﾌﾛｰｽﾙｰﾓﾉﾘｽ
ｳｫｰﾙﾌﾛｰﾌｨﾙﾀｰ

Figure 33
It was found by experiment that it was more effective to place the platinum NO2 generating
catalyst, shown in the left on this slide, in front of the filter shown on the right.
By placing the catalyst in front of the filter, the NO2 is forced to flow through theparticulate bed creating a higher rate of reaction to burn the particulate.

56

米国特許

Figure 34
This famous design was patented in February 1990 as US patent 4,902,487.

CRT® Layout Diagram
CRT® の構造

Figure 35
The convertor design that introduced into commercial use is shown in this slide. It was
introduced 1995 and named the Continuously Regenerating Trap or CRT system.

The picture shows the convertor design for a heavy duty diesel engine.
The catalyst to generate NO2 is shown in the front section. The wall flow filter is shown in
the rear section.

57

Figure 36
The first use occurred in Gothenburg, Sweden. Subsequently, other major cities have opted
for the use of CRT system on public utility vehicles.
You can see the CRT installed on a tanker truck in the picture on the left. This truck has
traveled over 300,000 miles with no filter blockage.

Major Cities Employing CRT® Systems
CRT® システムを導入している主要都市
San Francisco
Los Angeles

San Diego

LondonBoston
New York
Washington

Paris

GothenBurg
Stockholm
Copenhagen
BerlinHong Kong
Tokyo

Figure 37
Today, some 35,000 CRT systems are in operation in major cities throughout the world
ranging from Los Angeles in the West to Tokyo in the East

We at Johnson Matthey are now working on the development of a combined catalytic filter
system and catalytic nitrogen oxide reduction system to simultaneously remove diesel
particulate and nitrogen oxides from diesel engines -----But that is another story…..

58

We are now up to date and it is time to conclude this presentation……..
I hope you have enjoyed my historical review. I have tried provide an insight into thetechnical challenges that have been overcome on the way to clean air.
The past 30 years in emission control have been exciting and I have been proud to play arole in this industry which has done so much to benefit our environment.
I could of course have not done it without the help and support of my colleagues at Johnson
Matthey.
Many others throughout the world have also significantly contributed. Many are goodfriends, some of who are with us in the audience today.
To those who I have worked with, I would like to say thank you.
To my competitors I would like to say thank you. You have stimulated us at Johnson
Matthey to make better more cost-effective products for the automotive industry.
To my customers, I am eternally grateful for your support over the years.
To my wife Ann I am even more grateful for your support over the years…..
But before I go let me show you one more slide…....
I would like to show you a cumulative plot of Johnson Matthey’s catalyst production from1975 through to today.
ジョンソン・マッセイが製造した累積触媒数と汚染物浄化量

500

4 500

450

4 000

400

3 500

350
M illio n s C ata lys ts

3 000
300
2 500
250
2 000
200
1 500
150
1 000

100

P o llu tan t C o n ve rted (M illio n Me tric T o n n e s

C u m u la t iv e p lo t o f c a ta ly s ts p ro d u c e d b y
J o h n s o n M a tth e y v s . P o llu t a n t C o n v e rte d1 9 7 4 -2 0 0 2

5 00

50
0

0
1974

1979

1984

1989

1994

1999

C um ula tive C ata lysts (M illio ns)
C um ula tive P o lluta nt C o nverte d (M illion M e tric T onnes )Figure 38
If you look at the bars in this plot you will see we are close to reaching the production ofhalf a billion catalysts for catalytic convertors.
59

The line is an estimation of how many tons of pollution those catalysts have removed fromthe world’s atmosphere.
Amazingly, those catalysts have removed 4 Billion Tons of pollution from the atmospheresince the inception of our business.

Now, that is ECO Technology!

Figure 39
I am proud to be part of an Industry, which has so substantially benefited our environmentand has made the world healthier for us, our children and our grandchildren
Thank you very much, indeed, ladies and gentlemen for listening to my story this evening.
And thank you once again to the Honda Foundation for honoring me with this award. I am
truly most grateful.

Honto--ni Arigatou Gozaimashta,
Minasama Hontomata,Yoh--na May
May--I-yo Aru Show Wo Itadaki,
Kono Yoh
Honda Foundation Ni Kansha Itashimass.

60