Hydrocarbons on metal catalysts

Hydrogenolysis reactions of hydrocarbons on metal catalysts have been investigated in some detail. Extensive studies have been conducted on both alkanes and cycloalkanes. While a number of questions still remain with regard to mechanistic and kinetic details of the reactions, the general features seem reasonably clear. 

Metal catalysed skeletal reactions of hydrocarbons on metal catalysts. Dispersed metal catalysts. 

R. L. Burwell, Jr., "Deuterium as a Tracer in Reactions of Hydrocarbons on Metallic Catalysts, Accounts of Chemical Research 2, 289 (1969). 

O.V.Bragin and A.L.Liberman, Transformations of Hydrocarbons on Metal Catalysts (in Russian ), Moscow, 1981. 

Contents /. B. Butt Catalyst Deactivation and Regeneration. - /. Pasquon, U. Giannini Catal3d ic Olefm Pol)merization. - G. Maire, F. Garin Metal Catalysed Skeletal Reactions of Hydrocarbons on Metal Catalysts. - K. Foger Dispersed Metal Catalysts. 

The articles by J. R. Anderson, J. H. Sinfelt, and R. B. Moyes and P. B. Wells, on the other hand, deal with a classical field, namely hydrocarbons on metals. The pattern of modem wTork here still very much reflects the important role in the academic studies of deuterium exchange reactions and the mechanisms advanced by pioneers like Horiuti and Polanyi, the Farkas brothers, Rideal, Tw igg, H. S. Taylor, and Turkevich. Using this method, Anderson takes ultrathin metal films with their separated crystallites as idealized models for supported metal catalysts. Sinfelt is concerned with hydrogcnolysis on supported metals and relates the activity to the percentage d character of the metallic bond. Moyes and Wells deal with the modes of chemisorption of benzene, drawing on the results of physical techniques and the ideas of the organometallic chemists in their discussions. 

Cu in solid solution, 31 259-260 Scanning tunneling microscopy chemisorbed hydrocarbons on metals, 41 30 heteropoly compounds, 41 137 molecular precursors for tailored metal catalysts, 38 303-305... 

In typical stereochemical experiments, the reactivity of two or more compounds of the same structure but of different configuration is compared either in separate or competitive experiments. The method has been reviewed several times for heterogeneous catalytic reactions, mostly with respect to reactions of hydrocarbons on metals (16-18). The results concerning eliminations on acidic catalysts have been summarized in an article dealing with the mechanism of this type of reactions (12). Clarke and Rooney (17) have broadened the notion of the stereochemical approach to heterogeneous catalysis when they included into it all work in which mechanistic conclu-... 

Stereochemical Approaches to Mechanisms of Hydrocarbon Reactions on Metal Catalysts... 

Mechanisms of Hydrocarbon Reactions on Metal Catalysts J. K. A. Clarke andJ. J. Rooney Specific Poisoning and Characterization of Catalytically Active Oxide Surfaces... 

The dipolar MSSR applies strictly to a flat metal surface. However, the consideration by Pearce and Sheppard (93) that adsorbed layers are typically a few angstroms (tenths of nanometers) thick in relation to the diameters of larger metal particles in catalysts (up to tens of nanometers) led to the consideration that the MSSR could have substantial effects on the intensities of infrared absorptions from adsorbed species on metal catalysts with large particles. It has been estimated that parallel modes of vibration will have their infrared absorption bands substantially attenuated at metal particle diameters of greater than 2 nm (94). This is proving to be a very important consideration in the interpretation of the infrared spectra from adsorbed hydrocarbon species on metal catalysts (20, 95, 96) and has recently become widely accepted as valid (52, 54, 57, 62, 97). 

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