STRUCTURE SENSITIVITY IN THE REACTION OF METHANOL ON ZRO2

The reaction of methanol on the (100) and (110) surfaces of cubic zirconia was studied using temperature-programmed desorption (TPD) and high-resolution electron energy loss spectroscopy (HREELS). Methanol was found to adsorb dissociatively on both surfaces to form adsorbed methoxide and hydroxyl species. The primary reaction pathway for adsorbed methoxides was recombination and desorption as methanol. A fraction of the adsorbed methoxides (similar to 25%) underwent additional reactions which were dependent on the crystallographic orientation of the surface. On the (100) surface, methoxides decomposed near 630 K to produce CO and CH4. In contrast, on the (110) surface the primary methoxide decomposition pathway was oxidation to produce CH2O. This difference in reactivity can be related to the local atomic structure of each surface.