酸性介质中丙烯基硫脲对铜阳极溶出和阴极沉积过程影响的EQCM研究

采用循环伏安(CV)和电化学石英晶体微天平(EQCM)方法研究了酸性介质中铜阳极溶出和阴极沉积过程以及丙烯基硫脲(AT)对该过程的影响.结果表明,铜阳极溶出和阴极沉积过程的M/n分别为32.0和34.2g/mol,都是两电子过程,其间未检测到Cu(Ⅰ)中间产物.AT改变了铜阳极溶出和阴极沉积的历程.在含AT的溶液中,铜阳极溶出和阴极沉积过程的M/n分别为61.9和65.4g/mol,可指认铜阳极溶出产物为CuAT+,并提出了AT存在下Cu阳极溶出和阴极沉积过程的反应机理;从电极表面质量定量变化的角度提供了Cu阳极溶出和阴极沉积过程的新数据

Adsorption and Oxidation of 1,3-Butanediol on Pt and Sb,S Modified Pt Electrodes

应用电化学循环伏安和石英晶体微天平 (EQCM )研究了 1 ,3 -丁二醇 ( 1 ,3 -BDL )在Pt电极和以Sb、S吸附原子修饰的Pt(Pt/Sbad和Pt/Sad)电极上的吸附和氧化过程。从电极表面质量变化的结果分析 ,可认为 1 ,3 -丁二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 1 ,3 -丁二醇电催化氧化活性。与Pt电极相比较 ,饱和吸附Sb原子的Pt电极 ,1 ,3 -丁二醇氧化的峰电位负移了 0 2 5V ,峰电流增加了近 1倍。相反 ,Pt电极表面S吸附原子的氧化会消耗表面氧物种 ,饱和吸附S原子的Pt电极上 1 ,3 -丁二醇的电氧化受到抑制。本文从表面质量变化提供了吸附原子电催化作用的新数据。The processes of adsorption and oxidation of 1,3-butanediol on Pt and Pt modified with Sb and S in saturation(Pt/Sb ad and Pt/S ad )electrodes were studied by using cyclic voltammetry and electrochemical quartz crystal microbalance(EQCM).The results demonstrated that the oxidation of 1,3-butanediol depended strongly on oxidation states of electrode surface.Sb adatoms on Pt surface could adsorb oxygen at relatively low potentials,and exhibited catalytic effects for 1,3-butanediol oxidation.In comparison with the case of Pt electrode,the oxidation peak potential of 1,3-butanediol on Pt surface modified with Sb in saturation was negatively shifted about 250 mV with peak current being doubly increased.In a contrary,the oxidation of S adatoms consumed oxygen species of Pt electrode surface.As a consequence,the oxidation of 1,3-butanediol was inhibited on Pt surface modified with S in saturation.The EQCM studies provided quantitative results of surface mass changes during 1,3-butanediol oxidation,and threw new light in elucidating different effects of adatoms Sb ad and S ad on Pt electrode surface towards 1,3-butanediol oxidation.国家自然科学基金 (2 983 3 0 60 );; 福建省教委科研基金资助项目 (K2 0 0 110 1

Study on adsorption dsorption and oxidation of 1,4-butanediol at Pt and modified Pt electrodes

　运用电化学循环伏安和石英晶体微天平研究了1,4-丁二醇(1,4-BDL)在Pt电极及以Sb和S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,1,4-丁二醇的氧化与电极表面氧物种有着极其密切的关系,表面质量变化提供了吸附原子电催化作用的新数据.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1,4-丁二醇电催化氧化活性.与Pt电极相比,1,4-丁二醇在饱和吸附Sb原子的Pt电极上氧化的峰电位负移了0 20V,峰电流增加了1 5倍.相反,Pt电极表面S吸附原子的氧化会消耗表面氧物种,饱和吸附的S原子抑制了1,4-丁二醇的氧化.The processes of adsorption and oxidation of 1,4-butanediol on Pt,Pt/Sbad and Pt/Sad electrodes were studied by using cyclic voltammetry and electrochemical quartz crystal microbalance(EQCM).The results demonstrated that the oxidation of 1,4-butanediol 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 1,4-butanediol oxidation.In comparison with the case of Pt electrode,the oxidation peak potential of 1,4-butanedion on Pt surface modified with Sb was negatively shifted about 200 mV and the peak current was increased.On a contrary,the oxidation of S adatoms consumes oxygen species of Pt electrode surface.As a consequence,the oxidation of 1,4-butanediol was inhibited by the presence of Sad.The EQCM studies provided quantitative results of surface mass variation during 1,4-butanediol oxidation,and have thrown new light on elucidating different effects of adatoms Sbad and Sad on Pt electrode towards 1,4-butanediol oxidation.国家自然科学基金资助项目(29833060);; 福建省教委科研基金资助项目(K2001101)

An EQCM Study of Water Adsorption and Oxidation on Pt Electrodes in Sulfate Acid Sulotions

　应用电化学循环伏安和石英晶体微天平(EQCM)方法研究了0.1mol·L-1硫酸溶液中Pt电极表面的吸附和氧化过程.从电极表面质量变化的结果分析,可认为正向电位扫描时氢区表面质量的增加是由于水分子取代Had引起的,而双电层区的质量增加则是由于水的吸附模式逐渐由氢端吸附转向氧端吸附所致.根据频率变化和电量数据,进一步推算出水在双电层区是以低放电吸附形式出现的,1molPt原子和水分子只发生0.054mol的电荷转移.本文结果可为认识Pt电极表面过程提供定量的新数据.Simultaneous frequency and current responses during potential cycling of Pt electrode were measured in 0.1 mol·L-1 H2SO4 solution by using EQCM.Quantitative analysis of the mass change revealed that the increase of mass in the hydrogen and double_layer regions in a positive_going potential scan was due to water adsorption on the Pt electrode,further calculation indicated that water molecules adsorbed on Pt electrode in the double_layer regions through a low discharge quomodo .The EQCM studies provided quantitative results of surface mass variation during water adsorption and oxidation,and have thrown new light in elucidating the structure of double_layer between electrode and solution.作者联系地址：漳州师范学院化学系,厦门大学化学系固体表面物理化学国家重点实验室,漳州师范学院化学系,漳州师范学院化学系,漳州师范学院化学系 福建漳州363000 ,福建厦门361005 ,福建漳州363000 ,福建漳州363000 ,福建漳州363000Author's Address: 1.Department of Chemistry,Zhangzhou Normal College,Zhangzhou 363000,China,of Chemistry,Xiamen University,Xiamen 361005, Chin

EQCM study of effect of allyl thiourea on anodic dissolution and cathodic deposition of Cu in acidic media

The anodic dissolution and cathodic deposition of Cu and effect of allyl thiourea on the processes in acidic media were investigated by using cyclic voltammetry and EQCM. The experimental results demonstrated that there is only one current peak in the anodic dissolution and cathodic deposition of Cu, the M/n value of which is 32.0 and 34.2 g/mol, respectively, showing that the anodic dissolution and cathodic deposition of Cu correspond to the two-electron processes. No Cu (+) ions, adsorbed Cu ( I ) species or intermediate Cu (+) was evidenced by in situ EQCM measurements, allyl thiourea may change the mechanism of the anodic dissolution and cathodic deposition of Cu. The M/n values of the anodic dissolution and cathodic deposition of Cu in the presence of allyl thiourea are 61.9 and 65.4 g/mol, respectively, indicating the one-electron processes and producing Cu( I ) species. The mechanism of the anodic dissolution and cathodic deposition of Cu can be considered as: AT(solution) = AT(suface) ; Cu = Cu (+) (solution) + e; Cu (+) + AT = (CuAT) (+) (solution). The EQCM studies provided quantitative results of surface mass changes during cathodic deposition and anodic dissolution of Cu, and threw a new light in the elucidating electrodeposition and anodic dissolution of Cu