The Catalytic Dehydrogenation, Dehydroxylation and Dehydroxymethylation of Benzyl Alcohol. I. The Scope and the Kinetic Study

Abstract Benzyl alcohol was dehydrogenated to benzaldehyde when it was heated in the presence of various metal catalysts. It was found that the dehydrogenation was accompanied by a reductive dehydroxylation and dehydroxymethylation which led to the production of toluene and benzene respectively. The compositions of the products, which mainly consisted of benzaldehyde, toluene, and benzene, were greatly affected by the chemical nature of the catalysts used. The results of the reactions in a sealed tube or in an authoclave suggested that a pseudo-equilibrium between benzyl alcohol and benzaldehyde was attained during the reaction in a closed system. The formation of CO2, CH4, and other hydrocarbons as gaseous products was also observed. From these results, the catalytic dehydrogenation, dehydroxylation, and dehydroxymethylation were assumed to proceed competitively via a certain metal benzyl complex which is formed as an adsorbed transition complex upon the catalyst metal.