乙醇在粗糙铂电极上解离吸附与氧化的原位SERS研究

In-situ SERS of Dissociative Adsorption and Oxidation of Ethanol on Roughed Platinum Electrodes

采用循环伏安法和原位表面增强拉曼光谱(SERS)研究了乙醇在粗糙铂电极上的吸附和氧化行为,获得了乙醇在粗糙铂电极上解离吸附的表面增强拉曼光谱.研究表明,在酸性介质中,乙醇能在粗糙铂电极上自发地解离出强吸附物种CO,在低波数区检测到桥式和线性吸附CO的铂碳键的伸缩振动信息;乙醇在粗糙铂电极上的氧化反应受扩散步骤控制;从分子水平初步证实乙醇的氧化是通过双途径机理进行的.

The behaviors of adsorption and oxidation of ethanol on a roughened platinum electrode with high SERS activity were studied by using cyclic voltammetry and in-situ surface enhanced Raman spectroscopy, surface Raman spectra of dissociative adsorption of ethanol on Pt electrode in acid medium have been obtained. The results show that ethanol can be dissociated on the Pt surface in acid medium to produce poisoning intermediate CO, which suppresses the further oxidation of ethanol, and some informations of Pt-C and Pt-C-Pt stretching vibration from linearly-adsorbed and bridged-adsorbed CO located in low frequency were obtained, respectively. The investigation also shows that the electro-oxidtion of ethanol on the roughened platinum was a diffuse-controlled reaction in sulfuric acid. By correlating the in-situ SERS data with the electrochemical data, it was found that the oxidation of ethanol proceeded via the parallel mechanism.