Emission Control by Catalytic Converter, Jeevan B MJeevan B M
A catalytic converter is an emissions control device that converts toxic gases and pollutants in exhaust gas to less toxic pollutants. The catalytic converter was invented by Eugene Houdry, a French mechanical engineer and expert in catalytic oil refining. In the catalytic converter, there are two different types of catalyst at work, a reduction catalyst and an oxidation catalyst.
As we know air pollution is big challenge for the world
The air pollution due to automobile is 70% of total pollution of air pollution.
We have several way for controlling automobile pollution.
The most effective way is by using catalytic converter in automobile
In short catalytic converter are used to convert the harmful gas to harmless gas
Combustible engines releases so many harmful pollutants and with the use of catalytic converters this harmful pollutants are reduced to less harmful ones.
Emission Control by Catalytic Converter, Jeevan B MJeevan B M
A catalytic converter is an emissions control device that converts toxic gases and pollutants in exhaust gas to less toxic pollutants. The catalytic converter was invented by Eugene Houdry, a French mechanical engineer and expert in catalytic oil refining. In the catalytic converter, there are two different types of catalyst at work, a reduction catalyst and an oxidation catalyst.
As we know air pollution is big challenge for the world
The air pollution due to automobile is 70% of total pollution of air pollution.
We have several way for controlling automobile pollution.
The most effective way is by using catalytic converter in automobile
In short catalytic converter are used to convert the harmful gas to harmless gas
Combustible engines releases so many harmful pollutants and with the use of catalytic converters this harmful pollutants are reduced to less harmful ones.
A major part of the air pollution caused is due to the vehicular emission which is increasing at an alarming rate. The different types of vehicles like car, bus, truck etc. contribute a way as well as play a dominant duty in increasing air pollution. These vehicles find its running source mainly form the extracts of fossil fuels like petrol, diesel. The fuels undergo combustion to generate energy so as to support the vehicle for duty. The incomplete combustion of the fuels in the engine paves a way for production of products like the carbon monoxide, hydrocarbons and particulate matters. A high emission level is therefore a proved result. For the purpose of forcing the fuel to have efficient combustion and for reduction of the emission levels for reducing air pollution a wide range of processes are applicable. These include improvising engine design, fuel pre-treatment etc. Among these wide ranges of options available catalytic converter is found to be a better way for establishing an efficient combustion in the controller engine of the vehicle. Usage of noble group metal is an effective way for effective combustion like the platinum group metal serves way good for reducing the exhausts. With the help of secondary measures efficiency of the engine is improved as well. The techniques are still under development as because there are some limitations of the catalytic converters which are needed to be dealt with but the application of this technique has better achievement points as well.
In response to an increasing push for clean diesel emissions, medium and heavy duty diesel-powered trucks have adopted complex exhaust or emission aftertreatment systems.
These systems treat post-combustion gases after they leave the engine, reducing environmental impact without sacrificing power or performance.
Selective Catalytic Reduction (SCR) is an advanced active emissions control technology system that injects a liquid-reductant agent through a special catalyst into the exhaust stream of a diesel engine. The reductant source is usually automotive-grade urea, otherwise known as Diesel Exhaust Fluid (DEF). The DEF sets off a chemical reaction that converts nitrogen oxides into nitrogen, water and tiny amounts of carbon dioxide (CO2), natural components of the air we breathe, which is then expelled through the vehicle tailpipe.
SCR technology is designed to permit nitrogen oxide (NOx) reduction reactions to take place in an oxidizing atmosphere. It is called "selective" because it reduces levels of NOx using ammonia as a reductant within a catalyst system. The chemical reaction is known as "reduction" where the DEF is the reducing agent that reacts with NOx to convert the pollutants into nitrogen, water and tiny amounts of CO2. The DEF can be rapidly broken down to produce the oxidizing ammonia in the exhaust stream. SCR technology alone can achieve NOx reductions up to 90 percent
Biodiesel production in middle east opportunities and challenges jordan as ex...Ibrahim Farouk
Biodiesel production in middle east opportunities and challenges jordan as example jec edama 3rd nov. 2015
feel free to call us at info@biorotterdam.com
Selective catalytic reduction (scr) is use to control pollustion by vechical. SCR is connected to exhaust pipe of engine.In that ppt i give information about pollutent creat by engine and how to control pollutent. compare BS3, BS4 vehicle on base pollution.how amount of pollutant create and how to control is also mention
This is a presentation on the emission norms present in India i.e Bharat Stage and in Europe i.e Euro. it also has a comparison between the two as well as a timeline of the two.
A major part of the air pollution caused is due to the vehicular emission which is increasing at an alarming rate. The different types of vehicles like car, bus, truck etc. contribute a way as well as play a dominant duty in increasing air pollution. These vehicles find its running source mainly form the extracts of fossil fuels like petrol, diesel. The fuels undergo combustion to generate energy so as to support the vehicle for duty. The incomplete combustion of the fuels in the engine paves a way for production of products like the carbon monoxide, hydrocarbons and particulate matters. A high emission level is therefore a proved result. For the purpose of forcing the fuel to have efficient combustion and for reduction of the emission levels for reducing air pollution a wide range of processes are applicable. These include improvising engine design, fuel pre-treatment etc. Among these wide ranges of options available catalytic converter is found to be a better way for establishing an efficient combustion in the controller engine of the vehicle. Usage of noble group metal is an effective way for effective combustion like the platinum group metal serves way good for reducing the exhausts. With the help of secondary measures efficiency of the engine is improved as well. The techniques are still under development as because there are some limitations of the catalytic converters which are needed to be dealt with but the application of this technique has better achievement points as well.
In response to an increasing push for clean diesel emissions, medium and heavy duty diesel-powered trucks have adopted complex exhaust or emission aftertreatment systems.
These systems treat post-combustion gases after they leave the engine, reducing environmental impact without sacrificing power or performance.
Selective Catalytic Reduction (SCR) is an advanced active emissions control technology system that injects a liquid-reductant agent through a special catalyst into the exhaust stream of a diesel engine. The reductant source is usually automotive-grade urea, otherwise known as Diesel Exhaust Fluid (DEF). The DEF sets off a chemical reaction that converts nitrogen oxides into nitrogen, water and tiny amounts of carbon dioxide (CO2), natural components of the air we breathe, which is then expelled through the vehicle tailpipe.
SCR technology is designed to permit nitrogen oxide (NOx) reduction reactions to take place in an oxidizing atmosphere. It is called "selective" because it reduces levels of NOx using ammonia as a reductant within a catalyst system. The chemical reaction is known as "reduction" where the DEF is the reducing agent that reacts with NOx to convert the pollutants into nitrogen, water and tiny amounts of CO2. The DEF can be rapidly broken down to produce the oxidizing ammonia in the exhaust stream. SCR technology alone can achieve NOx reductions up to 90 percent
Biodiesel production in middle east opportunities and challenges jordan as ex...Ibrahim Farouk
Biodiesel production in middle east opportunities and challenges jordan as example jec edama 3rd nov. 2015
feel free to call us at info@biorotterdam.com
Selective catalytic reduction (scr) is use to control pollustion by vechical. SCR is connected to exhaust pipe of engine.In that ppt i give information about pollutent creat by engine and how to control pollutent. compare BS3, BS4 vehicle on base pollution.how amount of pollutant create and how to control is also mention
This is a presentation on the emission norms present in India i.e Bharat Stage and in Europe i.e Euro. it also has a comparison between the two as well as a timeline of the two.
Design and Development of Catalytic Converter for Reduction of Pollution by U...YogeshIJTSRD
The use of fossil fuels in automobiles mainly HC, CO and NOX which produce harmful green house gases. The main objective of catalytic converter is to reduce and control effect of harmful pollutants by converting toxic CO and NOX to non toxic CO2and H2O. CFD analysis is done in the present study of catalytic converter by taking three different materials for the make of catalytic converter such as stainless steel, Grey cast iron and aluminum at the time by varying different fluids such as methane, ethane and nitrogen at varying speeds of 2000 and2500R.P.M. V. Saran Tej | M. Rakesh Kumar | N. Satya Sandeep | N. Sai "Design and Development of Catalytic Converter for Reduction of Pollution by Using Transient and CFD Analysis" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-5 , August 2021, URL: https://www.ijtsrd.com/papers/ijtsrd43784.pdf Paper URL: https://www.ijtsrd.com/engineering/mechanical-engineering/43784/design-and-development-of-catalytic-converter-for-reduction-of-pollution-by-using-transient-and-cfd-analysis/v-saran-tej
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Exhaust analysis of four stroke single cylinder diesel engine using copper ba...ijsrd.com
Exhaust emissions of much concern are Hydrocarbon (HC), Carbon Monoxide (CO) and Nitrogen Oxide (NOx) from the automotive vehicles. Catalytic converter oxidizes harmful CO and HC emission to CO2 and H2O in the exhaust system and thus the emission is controlled. There are several types of problems associated with noble metal based catalytic converter. These factors encourage for the possible application of non-noble metal based material such as copper as a catalyst, which may by proper improvements be able to show the desired activity and can also offer better durability characteristics due to its poison resistant nature. The present work is aimed at using copper as a catalyst for catalytic converter. Wire mesh copper catalytic converter is developed for a volume of 1.54 m3. The experiment is carried out on four stroke single cylinder CI engine. The optimum values of exhaust emissions found at full load are HC (126 ppm), CO (0.03 %). By using copper based catalytic converter it is found that HC is reduced by 33 % and CO by 66 % at full load.
Emission Characteristics and Performance of Catalytic Converter A Reviewijtsrd
In recent years, several strategies such as fuel treatment, engine modification, EGR and catalytic converter have been introduced to control emissions from vehicles. Catalytic converter equipment is efficient and commonly used. Catalytic converters reduce emissions of carbon monoxide, hydrocarbons, nitrogen oxides and particulate matter from internal combustion engines and allow more strict pollution standards to be met. In this study paper different methods and strategies to increase efficiency of catalytic converter is discussed. The efficiency of the catalytic converter is updated according to literature survey improvements in design, shape and content. The hexagonal monolith shape was found to have better mechanical efficiency than the square shape. Catalytic converters based on nickel have cut HC by 40 percent and CO by 35 percent. Nobel metals are toxic and costly, so we can use non noble metals such as Cu, Ag, Au, Fe, etc. Ashish Kumar Soni "Emission Characteristics and Performance of Catalytic Converter: A Review" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-1 , December 2020, URL: https://www.ijtsrd.com/papers/ijtsrd38176.pdf Paper URL : https://www.ijtsrd.com/engineering/mechanical-engineering/38176/emission-characteristics-and-performance-of-catalytic-converter-a-review/ashish-kumar-soni
The concept of Photo catalysis is being incorporated into catalytic converter to increase the efficiency as well
as to reduce the production cost. Conventional converters make use of surface catalyst process using noble
metals like palladium and rhodium. Our concept works based on photo catalytic reactions by Titanium dioxide
and Zinc oxide thereby reducing the NOx emissions and CO emissions. Development of this proposal will reduce
the fabrication cost of catalytic converter as well as lay seeds of foundation for the future of photocatalytic
converters.
Catalytic Converter Made of Non-noble Material for an Automobileijsrd.com
This paper is reports on the review of catalytic converter made of non - noble material for an automobile. The converter made of the noble material is highly efficient but there is some major problem associated with these converters. First problem is the cost of the catalytic converter increased due to high cost of the noble material. Second problem is that they are operated at the higher temperature. Third problem is that the noble material is rarely available in earth crust and hence they are exhausted one day. Due to above problem associated with the noble material there is some option required for the noble material which is easily available at the lower cost. The non - noble material (Copper, Nickel, Zinc etc.) is perfect for the use into the catalytic converter instead of the noble material as they are easily available at low cost and operated at lower temperature than the noble material.
Three basic methods used to control engine emissions:
1)Engineering of combustion process -advances in fuel injectors, oxygen sensors, and on-board computers.
2) Optimizing the choice of operating parameters -two Nox control measures that have been used in automobile engines are spark retard and EGR.
3) After treatment devices in the exhaust system -catalytic converter.
What Exactly Is The Common Rail Direct Injection System & How Does It WorkMotor Cars International
Learn about Common Rail Direct Injection (CRDi) - the revolutionary technology that has made diesel engines more efficient. Explore its workings, advantages like enhanced fuel efficiency and increased power output, along with drawbacks such as complexity and higher initial cost. Compare CRDi with traditional diesel engines and discover why it's the preferred choice for modern engines.
Why Is Your BMW X3 Hood Not Responding To Release CommandsDart Auto
Experiencing difficulty opening your BMW X3's hood? This guide explores potential issues like mechanical obstruction, hood release mechanism failure, electrical problems, and emergency release malfunctions. Troubleshooting tips include basic checks, clearing obstructions, applying pressure, and using the emergency release.
In this presentation, we have discussed a very important feature of BMW X5 cars… the Comfort Access. Things that can significantly limit its functionality. And things that you can try to restore the functionality of such a convenient feature of your vehicle.
5 Warning Signs Your BMW's Intelligent Battery Sensor Needs AttentionBertini's German Motors
IBS monitors and manages your BMW’s battery performance. If it malfunctions, you will have to deal with an array of electrical issues in your vehicle. Recognize warning signs like dimming headlights, frequent battery replacements, and electrical malfunctions to address potential IBS issues promptly.
"Trans Failsafe Prog" on your BMW X5 indicates potential transmission issues requiring immediate action. This safety feature activates in response to abnormalities like low fluid levels, leaks, faulty sensors, electrical or mechanical failures, and overheating.
What Does the PARKTRONIC Inoperative, See Owner's Manual Message Mean for You...Autohaus Service and Sales
Learn what "PARKTRONIC Inoperative, See Owner's Manual" means for your Mercedes-Benz. This message indicates a malfunction in the parking assistance system, potentially due to sensor issues or electrical faults. Prompt attention is crucial to ensure safety and functionality. Follow steps outlined for diagnosis and repair in the owner's manual.
𝘼𝙣𝙩𝙞𝙦𝙪𝙚 𝙋𝙡𝙖𝙨𝙩𝙞𝙘 𝙏𝙧𝙖𝙙𝙚𝙧𝙨 𝙞𝙨 𝙫𝙚𝙧𝙮 𝙛𝙖𝙢𝙤𝙪𝙨 𝙛𝙤𝙧 𝙢𝙖𝙣𝙪𝙛𝙖𝙘𝙩𝙪𝙧𝙞𝙣𝙜 𝙩𝙝𝙚𝙞𝙧 𝙥𝙧𝙤𝙙𝙪𝙘𝙩𝙨. 𝙒𝙚 𝙝𝙖𝙫𝙚 𝙖𝙡𝙡 𝙩𝙝𝙚 𝙥𝙡𝙖𝙨𝙩𝙞𝙘 𝙜𝙧𝙖𝙣𝙪𝙡𝙚𝙨 𝙪𝙨𝙚𝙙 𝙞𝙣 𝙖𝙪𝙩𝙤𝙢𝙤𝙩𝙞𝙫𝙚 𝙖𝙣𝙙 𝙖𝙪𝙩𝙤 𝙥𝙖𝙧𝙩𝙨 𝙖𝙣𝙙 𝙖𝙡𝙡 𝙩𝙝𝙚 𝙛𝙖𝙢𝙤𝙪𝙨 𝙘𝙤𝙢𝙥𝙖𝙣𝙞𝙚𝙨 𝙗𝙪𝙮 𝙩𝙝𝙚 𝙜𝙧𝙖𝙣𝙪𝙡𝙚𝙨 𝙛𝙧𝙤𝙢 𝙪𝙨.
Over the 10 years, we have gained a strong foothold in the market due to our range's high quality, competitive prices, and time-lined delivery schedules.
Symptoms like intermittent starting and key recognition errors signal potential problems with your Mercedes’ EIS. Use diagnostic steps like error code checks and spare key tests. Professional diagnosis and solutions like EIS replacement ensure safe driving. Consult a qualified technician for accurate diagnosis and repair.
What Does the Active Steering Malfunction Warning Mean for Your BMWTanner Motors
Discover the reasons why your BMW’s Active Steering malfunction warning might come on. From electrical glitches to mechanical failures and software anomalies, addressing these promptly with professional inspection and maintenance ensures continued safety and performance on the road, maintaining the integrity of your driving experience.
Things to remember while upgrading the brakes of your carjennifermiller8137
Upgrading the brakes of your car? Keep these things in mind before doing so. Additionally, start using an OBD 2 GPS tracker so that you never miss a vehicle maintenance appointment. On top of this, a car GPS tracker will also let you master good driving habits that will let you increase the operational life of your car’s brakes.
Core technology of Hyundai Motor Group's EV platform 'E-GMP'Hyundai Motor Group
What’s the force behind Hyundai Motor Group's EV performance and quality?
Maximized driving performance and quick charging time through high-density battery pack and fast charging technology and applicable to various vehicle types!
Discover more about Hyundai Motor Group’s EV platform ‘E-GMP’!
Comprehensive program for Agricultural Finance, the Automotive Sector, and Empowerment . We will define the full scope and provide a detailed two-week plan for identifying strategic partners in each area within Limpopo, including target areas.:
1. Agricultural : Supporting Primary and Secondary Agriculture
• Scope: Provide support solutions to enhance agricultural productivity and sustainability.
• Target Areas: Polokwane, Tzaneen, Thohoyandou, Makhado, and Giyani.
2. Automotive Sector: Partnerships with Mechanics and Panel Beater Shops
• Scope: Develop collaborations with automotive service providers to improve service quality and business operations.
• Target Areas: Polokwane, Lephalale, Mokopane, Phalaborwa, and Bela-Bela.
3. Empowerment : Focusing on Women Empowerment
• Scope: Provide business support support and training to women-owned businesses, promoting economic inclusion.
• Target Areas: Polokwane, Thohoyandou, Musina, Burgersfort, and Louis Trichardt.
We will also prioritize Industrial Economic Zone areas and their priorities.
Sign up on https://profilesmes.online/welcome/
To be eligible:
1. You must have a registered business and operate in Limpopo
2. Generate revenue
3. Sectors : Agriculture ( primary and secondary) and Automative
Women and Youth are encouraged to apply even if you don't fall in those sectors.
3. INTRODUCTION
There are four possible cases of atmospheric pollution from the automobile. Without
emission control, a carburettor and fuel tank emit fuel vapour. The crankcase emits blow
by gases and fuel vapour, and the tailpipe emits exhaust gases that contain pollutants.
The pollutants are hydrocarbons (HC), carbon monoxide (CO), and nitrogen gases (NOx).
These air pollutants are harmful to plants and animals, including human being.
The need to control engine emissions was recognized as early as 1909. Due to the more
stringent rules and emission standards, automotive manufacturers begun to develop a
treatment device for exhaust gases known as catalytic convertor for their vehicle models.
4.
5. CATALYTIC CONVERTER
The catalyst convertor converts the
harmful pollutants in the exhaust
gases into harmless gases. It is
located in the exhaust system and all
exhaust gas must flow through it. The
catalyst is a material in catalyst
converter that causes a chemical
change without being a part of the
chemical reaction. The result in
exhaust gas leaving the catalyst
converter contains less HC, CO, NOx .
6. TYPES OF CATALYTIC
CONVERTER
1. The oxidization catalytic converter :-The
oxidation catalyst is the second stage of catalyst
converter. It reduces the unburned hydrocarbon
and carbon monoxide by burning (oxidizing) them
over a platinum palladium catalyst.
HC + O₂ → CO₂ + H₂O
2CO + O₂ → 2CO₂
7. 2. The reduction catalytic converter :-
The reduction catalyst is the first stage of the catalytic
converter. It uses platinum and rhodium to reduce
nitrogen oxide emissions.
2NO → N2 +O2
3. The three-way catalytic converter (TWC):-
TWCs have the advantages of performing the oxidation of CO, HC and the reduction of
nitrogen oxides (NOx) simultaneously. Noble metals used as the active phase in TWCs. Pd
are generally used.
The major reactions are the oxidation of CO and HC and reduction of NOx. Also, water
gas shift and steam reforming reaction occur.
8. 2CO + O2 → 2CO2
Oxidation HC + O2 → CO2 + H2O
Reduction/three-ways 2CO + 2NO → 2CO2 + N2
HC + NO → CO2 + H2O + N2
Water gas shifting CO + H2O → CO2 + H2
Steam reforming HC + H2O → CO2 + H2
9. Component of catalytic converter:-
a) Catalyst:-
These include oxides of base metals e.g. copper, chromium, nickel, cobalt etc. and the
noble metals platinum (Pt), palladium (Pd) and rhodium (Rh). Base metal oxides
although found to be effective at higher temperature but they sinter and deactivate
when subjected to high-end exhaust gas temperature of conventional SI (Spark-
Ignition) engine operation.
10. b) Substrate or support:-
i) Pellets :- The first catalytic converters of passenger cars in early 1970s used a bed of
spherical ceramic pellets. These are also known as packed bed catalytic converter. The spherical
pellets made of γ-alumina (γ – Al2O3). The material of pellets is selected to have a high
mechanical strength against crush and abrasion.
ii) Monolith:-In our daily practice a monolith is a ceramic block consisting of a large number of
small straight and parallel channels. A special mixture of clay binders and additives is pushed
through a sophisticated dye to create the monolith structure.
iii) Washcoat: -A thin layer of inorganic oxides known as wash coat is applied to the cells in
monolith structure to increase effective surface area for dispersion of active catalyst that
increase its contact with the reacting gases.
11. iv) Air to fuel ratio :- Conversion efficiency of NO, CO and HC as a function of the air - fuel
in a three way catalytic converter. There is a narrow range of air - fuel ratio near
stoichiometry in which high conversion efficiencies for all three pollutants are achieved.
12.
13. EFFECT OF COLD START EMISSION ON THE
EFFICIENCY OF CATALYTIC CONVERTER :-
While a catalytic converter is running under the ideal
operating conditions, it is very successful at purifying exhaust:
collecting and eliminating 97% of toxins including
hydrocarbons, nitrogen oxides, and carbon monoxide. But the
issue of cold-start emissions is that automobiles do not always
meet these conditions. An obvious solution to prevent cold-start
emissions would be to make the engine hotter, as fast as
possible.
14. LIMITATION:-
1) In the exhaust stream with temperatures up to 1000 °C the metal in
the catalyst is prone to deactivation by sintering, leading to a reduction
in surface area and hence catalytic activity.
2) Platinum used as catalyst have high cost and also vaporized at high
temperature.
3) Palladium also used as catalyst with the platinum having less ability of
absorption and desorption of oxygen.
4) Three – way catalytic converter CO2, which is also harmful for the
environment.
15. MODIFICATION IN CATALYTIC CONVERTER:-
1) Replacement of Platinum and Palladium:-
Due to high cost we can use another material as catalyst in
catalytic converter We can use Perovskite Oxide(CaTiO3) due to low
costs, high thermal stability, better redox properties.
2) Development of four – way catalytic converter:-
In this converter we use high alunimium content Zeolite which
absorb all the CO2 produced in three – way catalytic converter.
16. APPLICATION OF CATALYTIC CONVERTER :-
1) A catalytic converter is a device used to reduce the toxicity of emissions
from an internal combustion engine.
2) Catalytic converters are most commonly used in motor vehicle exhaust
systems.
3) Catalytic converters are also used on generator sets, forklifts , mining
equipment, trucks , buses, trains, and other engine-equipped machines
4) A catalytic converter provides an environment for a chemical reaction
wherein toxic combustion by-products are converted to less-toxic
substances.
17. CONCLUSION
Three-way catalyst with stoichiometric engine control systems remain the state of art
method for simultaneously controlling hydrocarbon, CO and NOx emissions from
vehicle. Due to high cost of platinum and operating limitation platinum based catalytic
converter motivates the investigators of alternative catalyst material, which have low
coast and provide high efficiency. catalytic converter is best option for reducing the
pollutant. It is essential for investigation and modification in catalytic to increase the
efficiency of catalytic converter.
18. REFERENCES
1) P. Pundir, Engine emissions pollutant Formation and Advances in Control
Technology, Narosa Publishing house, New Delhi, Chapter 1, pp. 1-10.
2) auto.howstuffworks.com/catalytic-converter.htm
3)www.wikipedia.com
4) http://www.easterncatalytic.com/education/tech-tips/catalyst-basics-platinum-
palladium-and-rhodium-%E2%80%93-key-ingredients-that-make-converters-
tick/