Activation barriers of CO oxidation on Pt-M (M = Ru, Sn) alloys

被引:5
作者
Oka, Toshlaki [1 ]
Mizuseki, Hiroshi [1 ]
Kawazoe, Yoshiyuki [1 ]
机构
[1] Tohoku Univ, Inst Mat Res, Sendai, Miyagi, Japan
关键词
direct methanol fuel cell; platinum alloy; electrocatalyst; carbon monoxide; density functional theory;
D O I
10.2320/jinstmet.70.495
中图分类号
TF [冶金工业];
学科分类号
0806 ;
摘要
Fuel cells have attracted attention in recent years because they are very energy-efficient. However, we have to face up to a serious problem in that platinum, which is the usual anode electrocatalyst, is readily poisoned by CO. In the case of the Direct Methanol Fuel Cell (DMFC), it is very important to develop new materials for use as electrocatalysts that exhibit good tolerance to CO, since CO is invariably present as an intermediate in the dissociation of methanol. The aim of this study is to examine the mechanism of H2O dissociation and of the CO + OH combination reactions in the CO oxidation process by calculating the adsorption energies and the activation barriers. In the case of Pt-Ru alloys, the activation barrier of the H2O dissociation reaction is almost the same as it is for pure Pt. The activation energy of the CO + OH combination reaction on Pt-Ru alloy is larger than that on pure Pt. Nevertheless, the adsorption energy of H2O is larger than that on pure Pt. On the other hand, the activation barrier and adsorption energies of H2O on Pt-Sn alloy are very close to the corresponding values on pure Pt. Moreover, the activation barrier for the CO + OH combination reaction on Pt-Sn alloy is lower than that on pure Pt.
引用
收藏
页码:495 / 499
页数:5
相关论文
共 23 条
[11]   Modeling the electro-oxidation of CO and H2/CO on Pt, Ru, PtRu and Pt3Sn [J].
Liu, P ;
Logadottir, A ;
Norskov, JK .
ELECTROCHIMICA ACTA, 2003, 48 (25-26) :3731-3742
[12]   Pattern recognition on the structure-activity relationship of nano Pt-Ru catalysts: Methodology and preliminary demonstration [J].
Lu, QY ;
Yang, B ;
Zhuang, L ;
Lu, JT .
JOURNAL OF PHYSICAL CHEMISTRY B, 2005, 109 (18) :8873-8879
[13]  
Markovic NM, 2002, SURF SCI REP, V45, P121, DOI 10.1016/S0167-5729(01)00022-X
[14]   CO oxidation on smooth and high area Pt, Pt-Ru and Pt-Sn electrodes [J].
Morimoto, Y ;
Yeager, EB .
JOURNAL OF ELECTROANALYTICAL CHEMISTRY, 1998, 441 (1-2) :77-81
[15]   Comparison of methanol oxidations on Pt, Pt|Ru and Pt|Sn electrodes [J].
Morimoto, Y ;
Yeager, EB .
JOURNAL OF ELECTROANALYTICAL CHEMISTRY, 1998, 444 (01) :95-100
[16]   CO on Pt(111): A puzzle revisited [J].
Olsen, RA ;
Philipsen, PHT ;
Baerends, EJ .
JOURNAL OF CHEMICAL PHYSICS, 2003, 119 (08) :4522-4528
[17]   ATOMS, MOLECULES, SOLIDS, AND SURFACES - APPLICATIONS OF THE GENERALIZED GRADIENT APPROXIMATION FOR EXCHANGE AND CORRELATION [J].
PERDEW, JP ;
CHEVARY, JA ;
VOSKO, SH ;
JACKSON, KA ;
PEDERSON, MR ;
SINGH, DJ ;
FIOLHAIS, C .
PHYSICAL REVIEW B, 1992, 46 (11) :6671-6687
[18]   Density functional theory study of the oxidation of CO by OH on Au(110) and Pt(111) surfaces [J].
Shubina, TE ;
Hartnig, C ;
Koper, MTM .
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 2004, 6 (16) :4215-4221
[19]  
Shustorovich E, 1998, SURF SCI REP, V31, P5
[20]   SOFT SELF-CONSISTENT PSEUDOPOTENTIALS IN A GENERALIZED EIGENVALUE FORMALISM [J].
VANDERBILT, D .
PHYSICAL REVIEW B, 1990, 41 (11) :7892-7895