Mixed metal catalysts geometric effect

This so called ensemble or geometric effect, however, is not the only reason for the distinct properties of mixed metal catalysts. The diluent metal can... 

There is no single interpretation to explain the effects of particle size, alloying, and metal-support interaction on the chemisorption and catalytic properties of supported metal particles. Depending on the particle size, the nature of co-metal and support, and the nature of the reaction, the change of chemisorption and catalytic properties can be interpreted in terms of geometric features, electronic modifications, and/or mixed sites. This is due to the formation of various adsorbed species and intermediates. Moreover, in many cases, the promotion of catalytic properties will be directly related to the method of catalyst preparation, which affects the architecture of the active site, with respect to chemical and electronic states of components and topology. 

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