Platinum-Catalyzed Oxidations of Organic Compounds by Ferric Sulfate: Use of a Redox Fuel Cell to Mediate Complete Oxidation of Ethylene Glycol by Dioxygen at 80°C

A number of alcohols, aldehydes, and carboxylic acids were oxidized under mild conditions (60–80°C, 3MH2SO4in water) by Fe(III) using a catalytic amount of Pt black to generate Fe(II) and protons. The extent of oxidation depended on the structures of the organic reductant and on reaction conditions. A redox fuel cell that catalyzed the complete oxidation of ethylene glycol by dioxygen at 80°C was assembled. Fe(II) generated by oxidation of ethylene glycol was reoxidized to Fe(III) at the anode of the cell. A V(V)/V(IV)/HNO3/O2redox system was used to catalyze the electrochemical reduction of dioxygen. Both the anode and cathode consisted of WDF graphite felt, the surface of which had been oxidized by boiling concentrated nitric acid for 15 min. A maximum power density of 9.9 mW/cm3of graphite felt was obtained at a cell voltage of 197 mV.