Diffusion on a nanoparticle surface as revealed by electrochemical NMR

被引：12

作者：

Tong, YY

Oldfield, E

Wieckowski, A

机构：

[1] Georgetown Univ, Dept Chem, Washington, DC 20057 USA

[2] Univ Illinois, Dept Chem, Urbana, IL 61801 USA

来源：

FARADAY DISCUSSIONS | 2002年 / 121卷

关键词：

D O I：

10.1039/b110800j

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：

Surface diffusion of chemisorbed CO (from MeOH electrochemisorption) on pure and Ru-modified nanoscale Pt electrocatalyst surfaces has been investigated by solid-state electrochemical NMR (EC-NMR) in the presence of supporting electrolyte. Temperature-dependent nuclear spin-spin and spin-lattice relaxation measurements enable the diffusion activation energy, E, to be deduced. It is shown that the activation energy E correlates with the steady state current for MeOH electro-oxidation. A simple two-dimensional collision theory model is proposed to explain this intriguing observation, which may provide new mechanistic insights into the promotion of CO-tolerance in Pt/Ru fuel cell catalysts.

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收藏

页码：323 / 330

页数：8

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