Abstract:

The important solid catalysts may be divided into two classes:the one is generally assumed to be multiphasic and multicomponent, e. g, metal and alloy catalysts, it is sofar difficult to elucidate the mechanism of their action. The other is monophasic and with well-defined crystal structure, e. g. zeolite, pillared-clay, polyoxometallate, certain mixed metal oxide etc., the active center of the latter may be envisaged as being dispersed in a spatially uniform fashion throughout its bulk. This point of view is deduced by tracing analogies with the chemistry of enzyme catalysts, focussed largely on their molecular structure and catalytic behaviour.

Key words: solid state chemistry, oxide catalyst, mixed oxide, enzyme