Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (05): 937-945.doi: 10.3866/PKU.WHXB201303081

• THEORETICAL AND COMPUTATIONAL CHEMISTRY • Previous Articles     Next Articles

Adsorption and Dissociation of Water on HfO2(111) and (110) Surfaces

LI Lu1, LI Yi1, GUO Xin2, ZHANG Yong-Fan1, CHEN Wen-Kai1,3   

  1. 1 Department of Chemistry, Fuzhou University, Fuzhou 350116, P. R. China;
    2 States Key Laboratory of Coal combustion, Huazhong University of Science and Technology, Wuhan, Hubei, 410074, P. R. China;
    3 Fujian Provincial Key Laboratory of Photocatalysis-State Key Laboratory Breeding Base, Fuzhou University, Fuzhou 350002, P. R. China
  • Received:2012-11-12 Revised:2013-03-08 Published:2013-04-24
  • Supported by:

    The project was supported by the Natural Science Foundation of Fujian Province, China (2012J01032, 2012J01041) and Foundation of State Key Laboratory of Coal Combustion of Huazhong University of Science and Technology, China (FSKLCC1110).

Abstract:

First-principles calculations based on density functional theory (DFT) with the generalized gradient approximation (GGA-PW91) have been used to investigate the adsorption and dissociation of H2O molecules on HfO2(111) and (110) surfaces at different sites with different coverages. It was found that the surface hafnium atom was the active adsorption position of the (111) and (110) surfaces when compared different adsorption energies and various geometrical parameters. Adsorption energies of water on the HfO2 (111) and (110) surfaces varied slightly as the coverage increased. It was shown that the most favorable configuration of H2O on the HfO2(111) and (110) surfaces corresponded to the coordination of H2O via its oxygen to a surface hafnium atom. Adsorption geometries, Mulliken population charges, density of states, and frequency calculations for HfO2-OH, HfO2-O, and HfO2-H at both surfaces were also carried out. The results showed that the hydroxyl group interacted with the surface by its oxygen atom to surface hafnium atoms. Isolated oxygen atoms bound to surface hafnium and oxygen atoms, while hydrogen atoms interact only with surface oxygen atoms to form hydroxyl groups. For the dissociation reaction, according to transition searching, H2O→H (ads)+OH (ads). The energy barriers were endothermic by 9.7 and 17.3 kJ· mol-1 for the (111) surfaces and exothermic by -59.9 and -47.6 kJ·mol-1 for the (110) surfaces.

Key words: Ddensity functional theory, HfO2, H2O molecule, Adsorption, Dissociation

MSC2000: 

  • O647