from The Open University
Alternatively you can skip the navigation by pressing 'Enter'.
Life: Creatures of the DeepThursday, 11th February 2016 10:00 - Eden EdenLife under the waves. Read more: Life: Creatures of the Deep
The London Markets: The Fruit And Veg Market: Inside New SpitafieldsAvailable until Sunday, 13th March 2016 00:40The fruit and veg trade in England was once a closed world dominated by traditional British costermonger families.... Read more: The London Markets: The Fruit And Veg Market: Inside New Spitafields
The Bottom Line: Winter 2015-16: Customer ServiceAvailable for over a year
Thinking Allowed 2016: Consumerism, Work-life balanceAvailable for over a year
More or Less: E-cigs, politics, school and birthdaysAvailable for over a year
OpenLearn Live: 10th February 2016A king with long arms; and the debate about assisted suicide. Free learning across the day. Read more: OpenLearn Live: 10th February 2016
OpenLearn Live: 11th February 2016The first king to unite Wales into a single kingdom - then more free learning across the day. Read more: OpenLearn Live: 11th February 2016
Landschaftliche VielfaltGerman regions and landscapes, local traditions and the notion of Heimat are at the centre of... Try: Landschaftliche Vielfalt now
English: skills for learningEnglish: skills for learning, is a free course for anybody who is thinking of studying for a... Try: English: skills for learning now
This free course is concerned primarily with the chemistry that underpins the operation of the three-way catalytic converter that is placed in the exhaust systems of motor vehicles in order to reduce the emissions of primary pollutants: carbon monoxide, oxides of nitrogen and volatile organic compounds, including hydrocarbons. Discussion of the various effects of these pollutants and the consequent introduction and refinement of 'automotive emission regulations' has not been included, nor is there a look forward to future research trends.
Having read this unit you should be able to:
- discuss how the gas mixture expelled from the engine, and the conversion performance of the three-way catalytic converter, depend on the air/fuel (A/F) ratio;
- list the chemical reactions whereby the three-way catalyst removes carbon monoxide (CO), hydrocarbons and oxides of nitrogen (NOx) from petrol vehicle exhausts;
- interpret the results of experimental studies (involving activity tests, kinetic measurements, adsorption studies and/or various surface science techniques) of the three-way catalyst and appropriate model systems;
- discuss possible mechanisms for the catalytic reactions removing CO, hydrocarbons and NOx from vehicle exhausts;
- outline the modes of deterioration of the three-way catalyst, and comment on the strategies that could be used to reduce H2S emissions.
- Current section: Introduction
- Learning outcomes
- 1. Overview
- 4.1 Exhaust pollutants
- 4.2 The three-way catalytic converter
- 4.3 Exhaust emission characteristics
- 4.4 The chemical reactions
- 4.5 Catalyst deterioration
- Keep on learning
Study this free course
Enrol to access the full course, get recognition for the skills you learn, track your progress and on completion gain a statement of participation to demonstrate your learning to others. Make your learning visible!
The three-way catalytic converter
Ensuring good quality air is essential for the protection of public health. Governments worldwide have adopted a range of increasingly demanding measures to curb air pollution with a particular focus on the emissions from motor vehicles. An important part of this strategy has been the development of the three-way catalytic converter to remove exhaust pollutants such as carbon monoxide, unburnt hydrocarbons and nitrogen oxides. This unit takes an in-depth look at the construction of this converter for petrol-driven vehicles and investigates the catalytic chemistry taking place at the molecular level. It is assumed that you already have a scientific background.
This unit is from our archive and is an adapted extract from Principles of chemical change (S342) which is no longer taught by The Open University. If you want to study formally with us, you may wish to explore other courses we offer in.
This free course includes adapted extracts from an Open University course which is no longer available to new students. If you found this interesting you could explore more free Chemistry courses or view the range of currently available OU Chemistry courses.
Copyright & revisions
Originally published: Wednesday, 1st June 2011
Last updated on: Thursday, 11th October 2012
- Creative-Commons: The Open University is proud to release this free course under a Creative Commons licence. However, any third-party materials featured within it are used with permission and are not ours to give away. These materials are not subject to the Creative Commons licence. See terms and conditions. Full details can be found in the Acknowledgements and our FAQs section.
- This site has Copy Reuse Tracking enabled - see our FAQs for more information.
If you enjoyed this, why not follow a feed to find out when we have new things like it? Choose an RSS feed from the list below. (Don't know what to do with RSS feeds?)
Remember, you can also make your own, personal feed by combining tags from around OpenLearn.
- Latest OpenLearn pages
- Latest pages from OpenLearn - Chemistry
- Latest pages tagged - Mafia
- Latest pages tagged - organised crime
- Latest pages tagged - emissions
- Latest pages tagged - Stan Cohen
- Latest pages tagged - event horizons
- Latest pages tagged - pus and poison
- Latest pages tagged - Valentine's day
- Latest pages tagged - alternative
- Latest pages tagged - finance
- Latest comments on this page
All our alternative formats are free for you to download, for more information about the different formats we offer please see our FAQs. The most frequently used are Word (for accessibility), PDF (for print) and ePub and Kindle to download to eReaders*.
*Please note you will need an ePub and Mobi reader for these formats.