Infrared spectroelectrochemistry of the oxidation of absolute methanol at a platinum electrode

Infrared spectroelectrochemistry has been used to identify the products of the oxidation of methanol at a polycrystalline platinum electrode in absolu te methanol solutions. A spectroelectrochemical cell, with potential contro l under ambient conditions and optical path under vacuum, provided spectra which were free of H2O and CO2 vapour absorptions. The SNIFTIRS potential s tep technique was used to obtain absorbance difference spectra which indica ted that methyl formate was the major methanol oxidation product in acidic, neutral, and alkaline methanol solutions. CO2 and formate ion were also sh own to be significant products under alkaline conditions. Spectra recorded with different infrared polarisations gave no evidence of adsorbed intermed iates or adsorbed oxidation products. (C) 1999 Elsevier Science S.A. All ri ghts reserved.