乙醇在不同介质中电氧化的原位表面增强拉曼光谱研究  

In-situ Surface-enhanced Raman Spectroscopic Investigation on Ethanol Electrooxidation in Different Media

作　　者：钟起玲[1] 张兵[1,2] 丁月敏[1] 刘跃龙[1] 饶贵仕[1] 王国富[1] 任斌[3] 田中群[3] 

机构地区：[1]江西师范大学化学化工学院 [2]天津大学理学院,天津300072 [3]厦门大学化学化工学院化学系,固体表面物理化学国家重点实验室

出　　处：《物理化学学报》2007年第9期1432-1436,共5页Acta Physico-Chimica Sinica

基　　金：厦门大学固体表面物理化学国家重点实验室基金(200511);江西省自然科学基金(0620025)资助项目

摘　　要：采用常规电化学伏安技术和电化学原位表面增强拉曼光谱(in-situ SERS)技术研究了不同介质中乙醇在粗糙铂电极上的电催化氧化行为.发现不论在酸性、中性还是碱性介质中,乙醇均能在粗糙铂电极上自发氧化解离生成强吸附中间体CO;碱性介质中,CO在粗糙铂电极上基本氧化完全的电位(0.20 V)比中性和酸性介质中(0.50 V)负移了约0.30 V.而乙醇在粗糙铂电极上CV正向扫描的氧化峰电位(-0.20 V)比酸性介质中(0.65 V)负移了约0.85 V.比较不同介质中乙醇和CO在粗糙铂电极上的氧化峰电流和峰电位可以发现,粗糙铂电极在碱性介质中对乙醇和CO的电催化氧化活性比中性和酸性介质中更强;可以推测,不论在酸性、中性还是碱性介质中,乙醇在粗糙铂电极上的氧化过程均按双途径机理进行.Electrochemical voltametric methods and in-situ electrochemical surface-enhanced Raman spectroscopy （SERS）were used to investigate the electrooxidation behavior of ethanol in different media on a roughened platinum electrode.It was found that ethanol could dissociate spontaneously to produce strongly adsorbed intermediate,CO,in acidic,neutral,and alkaline media on the roughened platinum electrode.The complete oxidation potential of CO（ad） on the roughened platinum electrode was negatively shifted about 0.300 V in the alkaline medium（0.20 V）compared with that in the acidic and neutral media（0.50 V）.The positive oxidation peak potential of ethanol was negatively shifted about 0.85 V in the alkaline medium（-0.20 V）than that in the acidic medium（0.65 V）.By comparing the oxidation current and the peak potential,it was found that the electrocatalytic activity of roughened platinum electrode for ethanol and CO oxidation in the alkaline medium was higher than in acidic and neutral media.The results suggested that ethanol was oxidized to CO2 on the roughened platinum electrode via parallel reaction mechanism in acidic, neutral or alkaline media.

关 键 词：乙醇氧化 粗糙铂电极 碱性介质 电化学原位表面增强拉曼光谱 

分 类 号：O621.2[理学—有机化学]