Preaching to the catalytic converted

Pioneering work at Cambridge University on catalysts, which could make cheaper catalytic converters for cleaning up car exhaust, has been rewarded with a Pounds 2 million grant this week.

The use of substances to speed up chemical reactions is essential in the chemicals industry, with 95 per cent of products made by the sector relying on their use. The work at Cambridge will help to improve the development of industrial processes and reduce the cost of off-the-shelf products which make use of industrial catalysts - such as catalytic converters for cars. Converters at present use expensive and rare platinum and rhodium compounds as catalysts.

David King, head of the chemistry department at Cambridge, explained that discovering which substances will make an appropriate catalyst is a trial and error process that has remained largely unchanged since the 1920s. But thanks to a breakthrough at Cambridge that has resulted from fundamental research into solid surfaces, chemists can look forward to using techniques that allow effective catalysts to be custom designed.

Dr King and his colleagues, Adrian Wander and Richard Lambert, have developed highly refined techniques for determining the structure of catalytic surfaces and the way surrounding molecules interact with them. Using techniques such as electron diffraction and scanning tunneling microscopy, the researchers are able to accurately determine where atoms are on the surface of catalysts. This allows the catalytic process of bond-making and breaking to be monitored and the surface structures to be manipulated in order to design novel, highly active and chemically specific catalysts.

A major finding of the research is that during a catalytic reaction, the surface of the catalyst itself changes its structure. This has a profound effect on the amount of reaction products generated. The reaction of carbon monoxide and oxygen on the surface of a platinum catalyst to produce carbon dioxide will help improve catalytic converters.