Oxidation of 2-Propanol to Acetone by Dioxygen on a Platinized Electrode under Open-Circuit Conditions

Article abstract of DOI:10.1021/j100339a051

This paper examines the catalytic oxidation of 2-propanol by dioxygen on a platinized platinum gauze electrode.Under open-circuit conditions, the rate of reaction was limited by mass transport of dioxygen to the catalyst surface and obeyed the rate law -d/dt = k⁰s>¹P_O2¹.The rate of reaction depended on the rate of stirring of the system.No kinetic deuterium isotope effect was observed upon substitution of 2-propanol-d₇ for 2-propanol-d₀.Under the reaction conditions employed, the open-circuit potential of the catalyst during the catalytic oxidation of 2-propanol indicated that the platinum surface was covered predominately with platinum hydride and not with platinum oxide.No catalyst deactivation due to reaction of dioxygen with surface platinum atoms were obserevd, and hydrogen peroxide could be substituted for dioxygen as the oxidizing agent in the reaction.The reaction is proposed to proceed by the formation of an intermediate surface alkoxide that dehydrogenates and produces acetone and surface hydrides.These surface hydrides then react with dioxygen, hydrogen peroxide, platinum oxide, or some other oxidizing species and yield (ultimately) water, possibly by an electrochemical local cell mechanism.