The nature of raney nickel, its adsorbed hydrogen and its catalytic activity for hydrogenation reactions (review)

The influence of catalyst preparation on the structure, texture and the metallic A1 content is reviewed. A correlation between the A1 content and the saturation magnetization indicates an electronic interaction with a d band of nickel. Studies of adsorbed hydrogen show that there is a reversible and an irreversible adsorption with an electronic interaction with d bands of nickel as revealed by magnetic methods. Neutron inelastic scattering detects bridged and linear adsorbed H species. Two examples of hydrogenation reactions, with liquid acetone and gaseous benzene, are described and the mechanisms are discussed in relation to the kinetics and the adsorbed hydrogen species.