title: Density functional study of methanol decomposition on clean and O or OH adsorbed PdZn(111).
abstract: Methanol is the future and clean fuel, and its chemistry on metal surfaces has received much attention. In this paper we explore methanol dissociation on the clean and O or OH covered PdZn(111) that mimics Pd∕ZnO catalyst studied as a promising catalyst for methanol steam reforming, using density functional theory at PW91 level and slab model. Our study demonstrates that unlike the situation on Pd (111), methanol preferentially undergoes the O-H bond scission on the PdZn (111). The presence of O and OH species hinders the C-H bond dissociation, but significantly reduces the O-H bond-breaking barrier. The present results indicate that in the course of methanol steam reforming, methanol first loses the hydrogen atom of the hydroxyl group, forming methoxy. This step is greatly enhanced when there are O and∕or OH species (i.e., after water dissociation happens). Analyses reveal that CH2O is formed mainly from CH3O, not from CH2OH.
authors.affiliation: Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, People's Republic of China.
authors.forename: Yucheng
authors.initials: Y
authors.lastname: Huang
authors.forename: Xiang
authors.initials: X
authors.lastname: He
authors.forename: Zhao-Xu
authors.initials: ZX
authors.lastname: Chen
mesh_terms: D000327:Adsorption; D005557:Formaldehyde / Q000138:chemical synthesis / Q000737:chemistry; D006878:Hydroxides / Q000737:chemistry*; D000432:Methanol / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D011789:Quantum Theory; D013499:Surface Properties; D015032:Zinc / Q000737:chemistry*
chemical_list: D006878:Hydroxides; D005557:Formaldehyde; D010165:Palladium; C031356:hydroxide ion; D015032:Zinc; D010100:Oxygen; D000432:Methanol