X-ray absorption studies on alloy formation in different carbon-supported Pt-Ru electrocatalysts

被引：15

作者：

Roth, C ^{[1
]}

Martz, N ^{[1
]}

Morlang, A ^{[1
]}

Theissmann, R ^{[1
]}

Fuess, H ^{[1
]}

机构：

[1] TH Darmstadt, Inst Mat Sci, D-64287 Darmstadt, Germany

来源：

PHYSICAL CHEMISTRY CHEMICAL PHYSICS | 2004年 / 6卷 / 13期

关键词：

D O I：

10.1039/b400763h

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Carbon-supported Pt-Ru (1 : 1) catalysts were synthesized from aqueous solutions of Pt IV and Ru IV salts by two different reduction methods and in an organic solvent according to a slightly-modified Boennemann synthesis. X-ray absorption spectroscopy was applied to characterize the in-house synthesized catalysts in comparison to a commercial carbon-supported Pt-Ru/C alloy catalyst purchased from E-TEK inc. Significant geometric differences were revealed by the conventional EXAFS analysis which are attributed to differences in particle size and alloy formation. In contrast to the commercial catalyst, which is at least partially alloyed, for the in-house synthesized catalysts a much smaller number of Pt-Ru nearest neighbours has been found pointing either towards a rather inhomogeneous alloy formation or to the formation of ruthenium oxide. These findings are in excellent agreement with the results of the "Atomic" XAFS; the lower the number of Pt-Ru nearest neighbour contributions the higher the R value at which the maximum of the AXAFS feature appears. The R value, however, is supposed to be directly reflective of the d band occupancy which decreases as the degree of alloy formation increases.

引用

页码：3557 / 3562

页数：6

共 32 条

[1] Analysis of the electrochemical characteristics of a direct methanol fuel cell based on a Pt-Ru/C anode catalyst [J].