PROPERTIES OF LACO03 AS A CATALYST IN ENGINE EXHAUST GASES

Catalytic conversions of carbon monoxide, hydrocarbons and nitric oxide by the complex multiple metal oxide of lanthanum and cobalt (LaCo03) were measured in the exhaust stream of a single cylinder research engine burning lead-free fuel. Emphasis is placed on the chemical changes occuring in the lanthanum-cobalt-oxide as a result of exposure to the engine exhaust atmosphere and its effect on catalytic activity. It was determined that the catalytic activity of the complex multiple metal oxide of lanthanum and cobalt for nitric oxide reduction was the result of the formation of a nonstoichiometric structure. The chemical formula of this compound is presented. This observation has significance in relation to the chemical and structural stability of the catalyst in the exhaust gas environment.