The development of catalysts for emission control from motor vehicles: early research at Johnson Matthey

Catalytic converters for the control of vehicle emissions have been in use since 1975 and are now an established part of the vehicle scene. However, in the early days of emissions control, catalysts were foreign concepts to the vehicle engineer and there was some resistance to fitting them to motor vehicles. Early catalysts were relatively simple in concept compared with today's systems; nevertheless it was an extremely challenging venture to fit catalysts in probably the most demanding of all industrial environments. This was done, of course, at a time when many of today's sophisticated analytical and characterisation tools were unavailable or just emerging. The development of emissions legislation is outlined and the response of the catalyst and motor industries to the legislation is discussed. The key issues in developing the early car exhaust catalysts, including supporting the catalyst, the choice of active metals, stability, poisons and poison resistance are presented.