DEMS Analysis of Small Organic Molecule Electrooxidation: A High-Temperature High-Pressure DEMS study

摘要

The electrooxidation of methanol, ethanol and ethylene glycol on a Pt/Vulcan catalyst was investigated over a wide temperature range [20 to 100°C] at 3 bar overpressure and under continuous electrolyte flow by differential electrochemical mass spectrometry [DEMS]. Oxidation of methanol, ethanol and ethylene glycol at 0.6 V at ambient temperatures yields CO{sub}2 current efficiencies of ～40, 5 and 4%, which increase to 100, 24 and 33% at 100°C, respectively. The apparent activation energies for the overall reaction and for oxidation to CO{sub}2 were found to be 58 and 64 kJ mol{sup}(-1) for methanol oxidation, for ethanol/ethylene glycol they were 41/32 kJ mol{sup}(-1) and 73/53 kJ mol{sup}(-1), respectively. The mechanistic and kinetic implications of these data and the importance of model studies under realistic reaction conditions will be discussed.