The Effect of Fuel and Oil Additives on Automobile Catalyst Performance

Stringent standards controlling the emission of exhaust pollutants from gasoline-fuelled spark ignition engines have necessitated studies of many factors that influence the efficiency of the catalysts used for the destruction of carbon monoxide, unburnt hydrocarbons and nitrogen oxides. This review of the literature considers the effects on the catalyst of lead, manganese and phosphorus, which may be present as additives in fuel or lubricating oils. The first two elements can be detrimental to catalytic activity, and also to the environment, so must be minimised. The deactivation caused by phosphorus can be avoided by the use of catalysts designed to be compatable with the specified lubricants. Catalysts containing platinum group metals remain the preferred means of controlling the three designated exhaust gases.