METAL-OXIDE CATALYSTS FOR LEAN NOX REDUCTION

A summary of the current understanding of the lean NO, reduction react ion on various metal oxides, particularly Cu-ZrO2, is presented. Whene ver appropriate, a comparison with the behavior of the corresponding Z SM-5-based catalysts is made. It is concluded that there are many mech anistic similarities between metal oxide-based and zeolite-based catal ysts. Thus, the catalytic properties are determined more by the nature of the active centers than by the nature of the support. Potential ad vantages offered by metal oxides should make them attractive candidate s for practical applications.