title: Photo-electrochemical Oxidation of Organic C1 Molecules over WO3 Films in Aqueous Electrolyte: Competition Between Water Oxidation and C1 Oxidation.
abstract: To better understand organic-molecule-assisted photo-electrochemical water splitting, photo-electrochemistry and on-line mass spectrometry measurements are used to investigate the photo-electrochemical oxidation of the C1 molecules methanol, formaldehyde, and formic acid over WO3 film anodes in aqueous solution and its competition with O2 evolution from water oxidation O2 (+) and CO2 (+) ion currents show that water oxidation is strongly suppressed by the organic species. Photo-electro-oxidation of formic acid is dominated by formation of CO2 , whereas incomplete oxidation of formaldehyde and methanol prevails, with the selectivity for CO2 formation increasing with increasing potential and light intensity. The mechanistic implications for the photo-electro-oxidation of the organic molecules and its competition with water oxidation, which could be derived from this novel approach, are discussed.
authors.affiliation: Institute of Surface Chemistry and Catalysis, Ulm University, 89069, Ulm, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Reichert
authors.affiliation: Institute of Chemical Engineering, Ulm University, 89069, Ulm, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Zambrzycki
authors.affiliation: Institute of Surface Chemistry and Catalysis, Ulm University, 89069, Ulm, Germany.
authors.forename: Zenonas
authors.initials: Z
authors.lastname: Jusys
authors.affiliation: Institute of Surface Chemistry and Catalysis, Ulm University, 89069, Ulm, Germany. juergen.behm@uni-ulm.de.
authors.forename: R Jürgen
authors.initials: RJ
authors.lastname: Behm
mesh_terms: D002384:Catalysis; D055664:Electrochemical Techniques; D004566:Electrodes; D004573:Electrolytes / Q000737:chemistry*; D005557:Formaldehyde / Q000737:chemistry*; D005561:Formates / Q000737:chemistry*; D000432:Methanol / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D055668:Photochemical Processes; D013499:Surface Properties; D014414:Tungsten / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D004573:Electrolytes; D005561:Formates; D010087:Oxides; D014867:Water; C030544:formic acid; D005557:Formaldehyde; C511604:tungsten oxide; D010100:Oxygen; D014414:Tungsten; D000432:Methanol
keywords: WO3; organic molecule oxidation; photo-electrochemistry; reaction mechanisms; water splitting