Ethanol reactions over Au–Rh/CeO2 catalysts. Total decomposition and H2 formation

The reaction of ethanol has been investigated on the surface of Au–Rh/CeO2 by temperature programmed desorption (TPD), infrared spectroscopy and in steady state conditions. Most of adsorbed ethanol is found in the form of ethoxides (ν O–C at 1045 and 1096 cm−1). Heating the surface resulted in the transformation of ethoxides to carbonates (ν COO at 1561 and 1347 cm−1) without the presence of stable acetaldehyde or formaldehyde species. By 673 K all surface species has been desorbed. The relative instability of these carbonates when compared to CeO2 or Rh/CeO2 indicates that Au is enhancing the rate of oxidation. Most of CO2 formed during TPD is resulting from carbonate decomposition. Catalytic reactions showed that both CO2 and H2 can be formed with high yield over a wide temperature range.