文摘
The ethanol-to-CO2 conversion in a direct ethanol fuel cell application, which should theoretically exchange 12 electrons/molecule, leads mainly to acetic acid and, in a small amount, to carbon monoxide (CO) at the surface of Sn and Rh oxide-modified anode materials. According to the amount of these intermediate products, the reaction mechanism was found to be thoroughly modified. Therefore, investigations with cyclic voltammetric CO stripping combined with in situ infrared spectroscopy have aided to assess how the amount of produced acetic acid influenced CO electrooxidation using Pt/C, Pt80Rh20/C, Pt–SnO2/C, or Pt80Rh20–SnO2/C as electrode material. Based on the results, the adsorption of CO was hindered when the acetic acid concentration increased and the potential of the CO oxidation process shifted toward higher values.