ON THE ROLE OF PROMOTERS IN HYDROGENATIONS ON METALS - ALPHA,BETA-UNSATURATED ALDEHYDES AND KETONES

Promoters of metal catalysts play an essential role in the hydrogenati on of unsaturated bonds, such as in carbonylic compounds. This promoti on is a key to a high selectivity to unsaturated alcohols in hydrogena tion of alpha,beta-unsaturated aldehydes. Analysis of the information available in the Literature on the adsorptions through the C=C and C=O groups, respectively, together with the information on the catalytic behaviour of the promoter-free and promoted catalysts, allows us to su ggest a model of surfaces active in selective hydrogenation of unsatur ated aldehydes.