Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (06): 1599-1606.doi: 10.3866/PKU.WHXB20100625

• CATALYSIS AND SURFACE STRUCTURE • Previous Articles     Next Articles

Comparison of Three Reaction Mechanisms for the Water Gas Shift Reaction on Au(111) Surface

LIU Xiao-Ming, NI Zhe-Ming, YAO Ping, XU Qian, MAO Jiang-Hong, WANG Qiao-Qiao   

  1. Laboratory of Advanced Catalytic Materials, College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032, P. R. China
  • Received:2010-01-15 Revised:2010-03-08 Published:2010-05-28
  • Contact: NI Zhe-Ming E-mail:jchx@zjut.edu.cn

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Abstract:

A detailed density functional theory (DFT) investigation revealed three possible mechanisms (redox mechanism, carboxyl mechanism, and formate intermediate mechanism) for the water-gas shift reaction on Au(111) surface. All the pertinent species (H2O, CO, OH, O, H, CO2, COOH, HCOO) were calculated. We obtained their preferred adsorption sites. We characterized the reaction pathway containing 14 elementary steps and calculated the reaction potential energy surfaces. The calculation results show that the carboxyl mechanism and the redox mechanism are feasible while the formate intermediate mechanism is unlikely because of its high formation barrier. Our calculations also show that the carboxyl mechanism is more probable compared with the redox mechanism and the most feasible reaction pathway is H2O→-H OH→+COCOOH→+OHCO2.

Key words: Density functional theory, Au(111) surface, Reaction mechanism