Active sites for heterogeneous catalysis by functionalisation of internal and external surfaces

Molecular modelling has the ability to provide the atomistic understanding of processes in catalysis. To be able to investigate the mechanisms of reactions we must first be certain of the active site of the catalyst. In this paper, we outline our recent work on methanol synthesis in which we used the polar surfaces of zincite as a model for the industrial catalyst, before detailing our investigation of Group 11 metals supported on metal oxides. Copper is known to promote industrial catalysis, while silver and gold have also been shown to be active at a much lower weight percent of metal (with gold being the most promising) for both methanol synthesis and the water gas shift reaction. We also present the first systematic study of the stability of Groups 4 and 14 metal impurities in the framework of silicalite. Throughout we assess the effect of the metal dopant on the atomic and electronic structure of the oxide support. All the work presented here has employed an embedded cluster approach suitable for studying impurities in solid lattices both at internal and external surfaces, which has been implemented in the software ChemShell.