Early stages in the oxidation of ethanol at low index single crystal platinum electrodes

Conventional electrochemical methods and in situ FTIR spectroscopy have been applied to study the early stages for adsorption and oxidation of ethanol at Pt(111), Pt(110), and Pt(100). Spectroscopic results show that the electrooxidation of ethanol on all three surfaces is characterised by the formation of acetaldehyde, acetic acid and carbon dioxide as soluble products. Linearly and bridge bonded CO are identified as adsorbed species. At Pt(110) other surface species containing CH and COH bonds are observed. In the hydrogen region of the Pt(100) surface, the interconversion between bridge and linearly bonded CO, turns out to be a common feature during the electrooxidation of small organic molecules. The important role played by adsorbed water is discussed. Adsorption of ethanol is the rate determining step. (C) 1997 Elsevier Science S.A.