Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (10): 2198-2206.doi: 10.3866/PKU.WHXB201307294

• THEORETICAL AND COMPUTATIONAL CHEMISTRY • Previous Articles     Next Articles

Quantum Chemical Study on the Adsorption of Formic on a Pt-Sn(111)/CAlloy Surface

TANG Fa-Wei1, GUO Wei-Min1, TANG Nan-Nan2, PEI Jun-Yan1, XU Xuan3,4   

  1. 1 College of Biological and Chemical Engineering, Guangxi University of Science and Techonology, Liuzhou 545006, Guangxi Zhuang Autonomous Region, P. R. China;
    2 Chengdu Textile College, Chengdu 611731, P. R. China;
    3 School of Chemistry and Environment, South China Normal University, Guangzhou 510006, P. R. China;
    4 Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, South China Normal University, Guangzhou 510006, P. R. China
  • Received:2013-06-15 Revised:2013-07-26 Published:2013-09-26
  • Contact: GUO Wei-Min E-mail:guoweimin8@163.com
  • Supported by:

    The project was supported by the Key Project of the Ministry of Education of China (210163), Natural Science Foundation of Guangxi Zhuang Autonomous Region, China (2010GXNSFA013045), Guangxi Scientific Research and Technology Development Projects, China (Guikegong 101420011), and Programfor Excellent Talents in Guangxi Higher Education Institutions, China (2012).

Abstract:

Density functional theory (DFT) and self-consistent periodic calculations were used to investigate the adsorption of formic acid (HCOOH) and carbon monoxide (CO) at eight sites, such as top, bridge, hcp and fcc, on a Pt-Sn(111)/C surface. The vibrational frequency, electric charge, energy band and density of states of HCOOH before and after adsorption on a Pt-Sn(111)/C surface were determined. The results show that before doping, the favored adsorption site for HCOOH and CO is the fcc-Pt3 site. After doping the surface with Sn, the Fermi level moves to the right, the conduction band broadens, and the valence and conduction bands lower slightly. The change of the electronic structure on Pt-Sn(111)/C promotes both the adsorption and dissociation of HCOOH, which can improve the performance of anode catalysts for direct formic acid fuel cells (DFAFCs). Based on the anti-poisoning analysis of the catalyst surface, it was also found that the adsorption energy of CO on Pt-Sn(111)/C surfaces is lower than that on Pt(111)/C ones. The results show that the adsorption energy of CO on Pt-Sn(111)/C decreases through two ways, and the anti-poisoning ability of the catalyst towards COis improved after doping with Sn.

Key words: Direct formic acid fuel cell, Pt-Sn(111)/C surface, Density functional theory, Electronic structure, Density of states

MSC2000: 

  • O646