TEMPERATURE-DEPENDENT METHANOL ELECTROOXIDATION ON WELL-CHARACTERIZED PT-RU ALLOYS

被引：557

作者：

GASTEIGER, HA ^{[1
]}

MARKOVIC, N ^{[1
]}

ROSS, PN ^{[1
]}

CAIRNS, EJ ^{[1
]}

机构：

[1] LAWRENCE BERKELEY LAB,BERKELEY,CA 94720

来源：

JOURNAL OF THE ELECTROCHEMICAL SOCIETY | 1994年 / 141卷 / 07期

关键词：

D O I：

10.1149/1.2055007

中图分类号：

O646 [电化学、电解、磁化学];

学科分类号：

081704 ;

摘要：

The kinetics of methanol electro-oxidation on well-characterized Pt-Ru alloy surfaces were measured in sulfuric acid solution as a function of temperature. The alloy surfaces were prepared in ultrahigh vacuum with the surface composition determined by low energy ion scattering. It was found that the activity of Ru towards the dissociative adsorption of methanol is a strong function of temperature. This change in the adsorptive nature of the Ru sites with temperature produced a variation in the optimum surface composition with temperature. The optimum surface had an Ru content which increased with increasing temperature, from close to almost-equal-to 10 atomic percent (a/o) Ru at 25-degrees-C to a value in the vicinity of almost-equal-to 30 a/o at 60-degrees-C. The shift in optimum composition with temperature was attributed to a shift in the rate-determining step from methanol adsorption/dehydrogenation at low temperature to the surface reaction between the dehydrogenated intermediate and surface oxygen at high temperature. The apparent activation energies were consistent with this change in the rate-determining step.

引用

页码：1795 / 1803

页数：9

共 36 条

[1] PREPARATION AND CHARACTERIZATION OF SUPPORTED PT-RU BIMETALLIC CLUSTERS - STRONG PRECURSOR SUPPORT INTERACTIONS [J].