An in situ DRIFTS study of ethanol adsorption and desorption was performed on Pt (Rh, Pd) supported on Al2O3 and Ca-Al 2O3. Different from the well-known acetate-intermediate reaction mechanism observed on Al2O3-supported metal catalysts, formate species are exclusively observed on Pt (Rh, Pd) supported on Ca-Al2O3, offering a new mechanism denoted as the formate-intermediate mechanism. The key factor in determining the change in mechanism is the reduced availability of surface oxygen and the enhanced C-C breaking ability of the metal catalyst upon Ca modification. The formate-intermediate mechanism is favored in the presence of noble metals in the following order: Pt > Rh > Pd.
- ethanol steam reforming
- reaction pathway