New insights into the methanol oxidation mechanism over Au/CeO2 catalyst through complementary kinetic and FTIR operando SSITKA approaches

The mechanism of methanol full oxidation over Au/CeO2 in the low temperature range has been clarified combining FT-IR spectroscopic results with kinetic calculations. A clear thermal effect of the infrared beam on the catalytic reaction was remarked and quantified. A global mechanistic model was proposed, providing the reaction order, the kinetic constants and the activation energy for the process, as well as valuable information on selected elemental steps. SSITKA experiments gave additional evidences on the formate decomposition as the rate determining step (RDS) of the reaction and proved the strict correlation between formate decomposition and CO2 yield, at different temperatures, further validating the kinetic model and differentiating the activation energy of the RDS from the apparent activation energy of the process as a whole.