The Oxidation Of Methanol On Hydroxylated M-Zro2(-111): A First-Principles Study

The oxidation of methanol (CH3OH) on hydroxylated monoclinic zirconia (H-m-ZrO2 (-111)) surface has been studied using slab periodic model and density functional theory. Both terminal-and bridging-type mechanisms were examined on the basis of two possible adsorption modes between CH3OH and hydroxyl groups (terminal and bridging) on H-m-ZrO2 (-111) surface. The calculation results show that the whole catalytic cycle can be marked by three reaction stages: the formation of CH3O via the decomposition of CH3OH (Stage I), the formation of HCOO via the oxidation of CH3O (Stage II), and the CO formation and regeneration of hydroxyl groups (Stage III). Taking potential energy surface (PES) into account, the bridging-type mechanism appeared to be the preferred one (CH3OH -> CH3O -> CH2O -> H2COO -> HCOO -> CO). The rate-determining step is identified to be the transformation of H2COO to HCOO and H2O with a barrier of 1.42 eV. The calculated results of this work should be useful in the search and design of new catalysts.