Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (01): 155-162.doi: 10.3866/PKU.WHXB20091224

• QUANTUM CHEMISTRY AND COMPUTATION CHEMISTRY • Previous Articles     Next Articles

CO and H Adsorption on Pt/WC(0001) Surface

MA Chun-An, LIU Ting, CHEN Li-Tao   

  1. State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology, Hangzhou 310032, P. R. China
  • Received:2009-06-29 Revised:2009-09-28 Published:2009-12-29
  • Contact: MA Chun-An E-mail:science@zjut.edu.cn

Abstract:

Density functional theory (DFT) calculations and periodic slab models were used to investigate the geometrical structures and surface energies of two different WC(0001) surfaces. The adhesion energies and separation work of Pt monolayer adhesion on the two WC(0001) surfaces at high-symmetry sites were calculated. Results show that the W-terminatedWC(0001) is favored and that theW-terminated surface with Pt monolayer adhesion at the hcp site is the most stable PtML/WC(0001) structure. On the basis of the above results, the adsorption behavior of the CO molecule and hydrogen atom on the PtML/WC(0001) surface was compared with those obtained on the Pt(111) surface with a surface structure similar to the PtML/WC(0001) surface. At a low coverage of 0.25 ML (monolayer), an obvious elongation of the Pt—C distance and a decrease in CO adsorption energy show that the PtML/WC(0001) surface, relative to the Pt(111) surface, exhibits much improved resistance to CO poisoning. The density of states further explains the bonding mechanism of CO and Pt atoms on different surfaces. At the same coverage, the maximum hydrogen adsorption energy on the PtML/WC(0001) surface is equal to or even slightly higher than that on the Pt(111) surface. This suggests that Pt/WC possesses good catalytic activity during the hydrogen oxidation reaction and is a promising alternative anode catalyst for proton exchange membrane fuel cells (PEMFC).

Key words: Density functional theory, Pt/WC(0001) surface, CO poisoning, Density of state, Hydrogen oxidation reaction

MSC2000: 

  • O641