Kinetic Studies on the Catalytic Synthesis of Benzyl Cyanide from 2-Phenylethanol and Ammonia

Abstract

Vapor-phase synthesis of benzyl cyanide from 2-phenylethanol and ammonia was studied over Ni-Cu-SiO₂ catalyst in the presence of hydrogen. Experiments were carried out in a flow reactor system under atmospheric pressure at 300°. The main product was benzyl cyanide, and toluene and phenethylamine were also produced. The Ni-Cu-SiO₂ catalyst (Ni/Cu=3/1) gave the best selectivity for benzyl cyanide, 80%. The deactivation of this catalyst was negligible. By kinetic analysis, the rate of loss of 2-phenylethanol was found to show a first order dependency on the partial pressure of 2-phenylethanol, and was not affected by the partial pressures of ammonia and hydrogen. The experimental data were well interpreted by a model in which phenethylimine was produced as an intermediate and was then dehydrogenated to benzyl cyanide.