Mixed metals 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. 

In the previous section we have shown the capability of the method for correctly describing different geometrical environments for pure Fe systems. In this section we test it in mixed Fe systems, where new ingredients are present like interfaces and hybridization effects. We have chosen Fe-Ag systems because Ag is a noble metal substrate often used in experimental growth processing in order to minimize the interference of the overlayer-to-substrate bonding with the interlayer bonding. In addition, there exist available data from ab-initio calculations to compare our results. 

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