Investigation of the hydrogenation reactivity of some organic substrates using an electrocatalytic method

The hydrogenation reactivity of some classes of organic substrates (alpha,beta-unsaturated ketones, benzaldehydes and acetophenones) was investigated using an electrocatalytic method (undivided cell, nickel sacrificial anode and water/methanol solvent). During the process a nickel deposit is produced on the cathode surface, at the same time that hydrogen is generated by water reduction. Nickel deposit morphologies (catalyst surface) were investigated, taking into account different cathode matrix materials (Cu, Ni, Fe, Fe/Ni (alloy 64:36)). The electrocatalytic method was evaluated by electrochemical efficiency of the hydrogenation process ((hydrogenation theoretical charge/experimental charge) x product yield). It was observed that Ni deposit/Ni cathode matrix ensemble exhibits slightly better catalytic activity, likely due the nanostructure of the nickel deposit. Moreover, the reactivity order determined through the electrochemical efficiencies (alpha,beta-unsaturated ketones > benzaldehydes > acetophenones) is the same as that found in the literature. (C) 2009 Elsevier B.V. All rights reserved.