Acta Phys. -Chim. Sin. ›› 2014, Vol. 30 ›› Issue (10): 1847-1854.doi: 10.3866/PKU.WHXB201407141

• THEORETICAL AND COMPUTATIONAL CHEMISTRY • Previous Articles     Next Articles

Hydrodesulfurization Mechanisms of Thiophene Catalyzed by Au/Pd(111) Bimetallic Surfa

ZHANG Lian-Yang, SHI Wei, XIA Sheng-Jie, NI Zhe-Ming   

  1. Laboratory of Advanced Catalytic Materials, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310032, P. R. China
  • Received:2014-06-03 Revised:2014-07-11 Published:2014-09-30
  • Contact: NI Zhe-Ming E-mail:jchx@zjut.edu.cn

Abstract:

The formation energy of different ensembles on Pd(111) surfaces containing N (N=1-4) Au atoms were investigated using a density functional theory model. The best model for exploring the adsorption of thiophene was selected, and the mechanism of competitive hydrodesulfurization on a Au/Pd(111) bimetallic surface was investigated. The results showed that Au/Pd(111) has the lowest formation energy, and adsorption at the hexagonal close-packed site is most stable when the thiophene plane is tilted at 30° to the Au/Pd(111) bimetallic surface with S atom. The reactions are exothermic, and desulfurization can be either direct or indirect. The direct desulfurization pathway has a low activation energy, but it is difficult to control the products. The indirect desulfurization pathway is the best fit for the cis-hydrogenation process; C―S cleavage has the highest reaction energy barrier, and is the rate-determining step. The activation energy barrier of the rate-determining step on Au/Pd(111) is lower than those on Au(111) and Pd(111). This indicates that bimetallic AuPd is more active than single Au and Pd in the hydrodesulfurization of thiophene.

Key words: Density functional theory, Thiophene, Au/Pd(111) bimetallic surface, Adsorption, Hydrodesulfurization

MSC2000: 

  • O641