Methanol decomposition on single crystal Cu2O

CH3OD decomposition has been studied over the stoichiometric, nonpolar (111) and polar, copper‐terminated (100) surfaces of Cu2O. Thermal desorption studies for monolayer coverages of methanol at 90 K show similar conversions, but the product distributions vary significantly, indicating a structure sensitive reaction. The (111) surface shows a maximum selectivity for complete oxidative dehydrogenation to CO, while the (100) surface shows a maximum selectivity for partial dehydrogenation to CH2O. Thermal desorption spectroscopy (TDS) and x‐ray photoelectron spectroscopy (XPS) data are consistent with a decomposition pathway which proceeds through a methoxy intermediate for both surfaces. Possible origins for the structure sensitivity are discussed.