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 CH20. 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. © 1990, American Vacuum Society. All rights reserved.