Surface migration and the influence of catalyst supports

The type of catalyst most commonly used in studies of the hydrogenation of unsaturated hydrocarbons is one in which the metal is dispersed upon a support such as alumina or silica. Although for many years it was generally thought that the support was catalytically inert, studies over the past few years have suggested that this may not be the case and there is a growing body of evidence to suggest that the support may influence the 

Indisputable evidence for the occurrence of hydrogen spill-over exists although the mechanism whereby it occurs is still not clear. Benson et al. 

In the foregoing sections, the various aspects of the metal-catalysed hydrogenation of unsaturated hydrocarbons have been discussed. In this final section, it is appropriate to attempt to summarise, in a general way, the current state of knowledge of the subject and to make suggestions as to possible future developments. 

Seiwood, Adsorption and Collective Paramagnetism, Academic Press, New York, 1962. 

Thomas and W.J. Thomas, Introduction to the Principles of Heterogeneous Catalysis, Academic Press, New York, 1967, Chap. 2. 

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