Ambient pressure hydrogenation of alpha-methylstyrene using hydrogen transfer agent

A mediator-assisted electrochemical pathway for reduction of alpha-methyl styrene to cumene is investigated. Ambient pressure and low temperature hydrogenation is carried out in an emulsion of the reactant, an organic solvent and water, to which a suitable surfactant is added. The mediator employed in the study hydrogenates alpha-methylstyrene via a chemical step on the solid catalyst while the former is regenerated electrochemically at the cathode. Alpha-methylstyrene was successfully hydrogenated to cumene using both catalytic transfer hydrogenation and mediator assisted electrochemical hydrogenation. Complete conversion was achieved at a mediator concentration of 0.5M and at an applied potential of -1.3V vs. SCE at 60°C. The influence of the applied current density, concentration and the type of electrode on the rate of hydrogenation is investigated. A mathematical model that takes into consideration the reaction chemistry is proposed and validated using the experimental data.