Pt及其修饰电极上甲醇吸附和氧化的CV和EQCM研究  

Adsorption and Oxidation of Methanol on Pt and Sb, S Modified Pt Electrodes Using Cyclic Voltammetry and EQCM

作　　者：陈国良[1] 陈声培[2] 林珩[1] 郑杏红[1] 孙世刚[2] 

机构地区：[1]漳州师范学院化学系,福建漳州363000 [2]厦门大学化学系固体表面物理化学国家重点实验室,福建厦门361005

出　　处：《电化学》2001年第4期452-458,共7页Journal of Electrochemistry

基　　金：国家自然科学基金 (2 98330 6 0 ) ;教育部博士点专项科研基金 (19990 384 0 3);福建省教委科研基金资助项目

摘　　要：运用电化学循环伏安和石英晶体微天平 (EQCM )研究了 0 .1mol·L- 1H2 SO4 溶液中甲醇在Pt电极和以Sb ,S不可逆吸附原子修饰的Pt(Pt/Sbad和Pt/Sad)电极上的吸附和氧化过程 .结果表明甲醇的氧化与电极表面氧物种有着极其密切的关系 .Pt电极表面Sb吸附原子能在较低的电位下吸附氧 ,可显著提高甲醇电催化氧化活性 .与Pt电极相比较 ,Sb吸附原子修饰的Pt电极使甲醇氧化的峰电位负移了 0 .13V .相反 ,Pt电极表面S吸附原子的氧化会消耗表面氧物种 ,抑制了甲醇的电氧化 .The processes of adsorption and oxidation of methanol on Pt, Pt/Sb ad and Pt/S ad electrodes were studied by using cyclic voltammetry and electrochemical quartz crystal microba_lance (EQCM). The results demonstrated that the oxidation of methanol depends strongly on oxidation states of electrode surface. Sb adatoms on Pt surface can adsorb oxygen at relatively low potentials, and exhibit catalytic effects for methanol oxidation. In contrast to Pt electrodes, the oxidation peak potential of methanol in this case negatively shifted to about 130 mV. In a contrary, the oxidation of S adatoms consumes oxygen species of Pt electrode surface. As a consequence, the oxidation of methanol was inhibited by the presence of S ad . The EQCM studies provided quantitative results of surface mass variation during methanol oxidation, and have thrown new light in elucidating different effects of adatoms Sb ad and S ad on Pt electrode surface towards methanol oxidation.

关 键 词：石英晶体微天平 PT电极 修饰电极 甲醇 循环伏安 铂电极 吸附 氧化 

分 类 号：O646[理学—物理化学]