非水体系中甲醇在粗糙铂电极上解离吸附的表面增强拉曼光谱研究

SERS Investigation on the Dissociation of Methanol on a Roughened Pt Electrode in Nonaqueous System

利用共焦显微拉曼系统和表面增强拉曼散射(SERS)效应研究了非水体系中甲醇在粗糙铂电极上的解离吸附过程.结果表明：甲醇在粗糙铂电极上解离吸附后产生了毒性中间物CO，在较负的电位区间内，H与CO共吸附于电极表面并影响CO的吸附行为.随电位正移，vPt－C的变化可以用电化学Stark效应进行解释，而VC－O的变化则是由于电化学Stark效应和CO偶极耦合的共同作用所引起的.

By utilizing SERS (Surface - enhanced Raman Scattering) technique and a confocal microprobe Raman system, the dissociation of methanol on a roughened platinum electrode in nonaqueous system was investigated. It is found that upon the dissociation of methanol on a roughened platinum electrode, carbon monoxide exists on the surface as the poisoning intermediate. At relative negative potentials, PI may coadsorb with CO on the electrode surface, and thus influence the spectral feature of CO signal. Positive movement of the potential, the variation of nu (pt-C) can be explained by the electrochemical Stark effect while the change of nu (C-O) can be interpreted by the combination of the electrochemical Stark effect and the dipole - dipole coupling effect.