Oxidizing Ethanol and 2-Propanol by Hypochlorous Acid Generated from Chloride Ions on HxWO3 Photoelectrodes

Photoelectrochemically oxidizing aqueous chloride electrolytes (1 M NaCl, pH(3)) to hypochlorous acid proceeds on HxWO3 semiconducting photoelectrodes using 405 nm illumination at 100 mW/cm(2) with 1.0 V versus Ag/AgCl constant potential chronoamperometry. The hypochlorous acid serves as an oxidation agent upon adding 100 mM ethanol or 2-propanol into the solution. H-1 NMR spectroscopy shows that 90% of the charge passed results in oxidized products (acetaldehyde and acetic acid or acetone). Chemically oxidizing ethanol by calcium hypochlorite shows that both light and the HxWO3 surface enhance the reaction rate.