恒电位条件下制备聚苯胺PAn及其电化学行为

恒电位条件下在玻碳电极上用电化学聚合法制备了聚苯胺膜，研究了聚合条件如聚合电位，聚合介质，苯胺浓度等对聚苯胺膜化学性质的影响，从而确定了制备聚苯胺的最佳聚合方法和条件，并讨论了在不同支持电解质溶液中和不同ＰＨ值条件下ＰＡｎ膜的循环伏安行为，认为５５０ｍＶ出现的氧化还原峰与阴离子的掺杂有关。     

纳米纤维聚苯胺膜在不锈钢电极表面的生长过程

研究了脉冲电流法(PGM)聚合苯胺时, 纳米纤维聚苯胺(PANI)膜在不锈钢(SS)电极表面的生长过程. 用计时电位法和扫描电子显微镜(SEM)表征了聚苯胺生长过程的电化学特征和微观形貌; 并通过循环伏安(CV)法研究了苯胺的聚合速率. 结果表明, 聚苯胺的生长经历了两个阶段, 首先是在裸不锈钢电极表面上形成颗粒状聚苯胺, 此时聚合电位约为1.10 V, 经历了30 s后, 电极表面被一层颗粒状聚苯胺膜所覆盖; 在此基础上, 聚苯胺以纳米纤维状结构继续生长, 当颗粒状聚苯胺被纳米纤维状聚苯胺膜完全覆盖时, 聚合电位降至0.75 V左右并保持稳定.     

苯胺在高氯酸溶液中恒电流法电化学聚合研究

本文在对苯胺在高氯酸溶液中电流聚合进行研究，内容包括在铂圆盘电极上影响苯胺电化学聚合的因素，如苯胺及高氯酸浓度，恒电流密度及聚合总电量（Ｑｒ）聚合电位等，实验结果表明，在合适的条件下制得的聚苯腚（ＰＡＮＩ）膜电极，其氧化还原电量（Ｑｔ）和Ｑｒ的比值接近了１００％的并对聚苯胺（ＰＡＮＩ）膜电极的电化学性质进行了探讨。     

原位紫外-可见光谱和电化学方法研究苯胺聚合过程中的降解

用电化学及光谱电化学研究了硫酸溶液中苯胺在玻碳电极上的聚合降解过程 ,在 - 0 2～ 1 0V电位范围 ,循环伏安图显示了四对氧化还原峰 .通过比较聚苯胺 (PAn)膜在硫酸空白溶液和含对氨基苯酚 (PAP)的硫酸溶液中的循环伏安曲线及电化学聚合时溶液的紫外 可见吸收光谱 ,证明了PAn膜的降解产物PAP的存在 ,同时原位现场紫外 可见吸收光谱法初步研究了苯胺聚合降解的动力学过程 .     

聚苯胺膜电化学原位导电性的测定及其反应动力学

自行开发了电化学原位膜导电性测量仪(ECC). 该测量仪将电化学的电位控制方法与电导率的测量有机地结合在一起, 同时辅以双带及阵列探针电极, 可在电化学电位调制下测定原位聚合物膜导电性的变化, 特别是可以进行高时间分辨的动力学测量. 以此为基础, 测定了对电化学电位调制下导电聚合物膜导电性能, 研究了电化学聚合的聚苯胺膜在一系列不同电位老化条件下的反应动力学.     

零流电位法考察聚苯胺膜的pH响应性质

将经电化学聚合的聚苯胺膜修饰的铅笔芯电极连接于一种新型电化学检测系统中,采用零流电位法考察了聚苯胺膜的pH响应性质。结果表明:试验制得的聚苯胺膜主要以中间氧化态形态存在,在B-R缓冲溶液中pH可控的质子化和去质子化形态转换,导致零流电位E_(ZCP)-pH曲线呈现两段相交的线性关系,其pH范围分别为pH 1.81～5.43及pH 5.43～9.91,两直线的交叉点在pH 5.43处,由此求得中间氧化态的pK_a值为5.43。     

苯胺电化学聚合机理的研究

主要应用电化学方法研究了苯胺及其电化学聚合产物─—聚苯胺的循环伏安曲线，同时讨论了苯胺的存在对４－氨基二苯胺循环伏安曲线的影响。结果表明：随着苯胺聚合的进行，聚苯胺同时发生降解；苯胺电化学聚合按“白催化机理”进行。     

循环伏安法的电扫描方式对苯胺聚合产物形貌影响的观察

在含有0.2 mol.L-1苯胺的0.5 mol.L-1H2SO4溶液中,以扫描速度50 mV.s-1,扫描电位为-0.1~0.9 V,采用循环伏安法(CV),在金属Ti基体上,通过控制扫描方式分别得到了颗粒状、纤维状及管-片状的苯胺聚合产物,分析了形成不同形貌聚苯胺的原因,并通过扫描电子显微镜(SEM)、循环伏安法和电化学阻抗谱(EIS)对不同形貌聚苯胺的结构和性能进行了表征.结果表明,不同形貌聚苯胺的形成是由于聚苯胺的成核及生长模式不同,而无论何种形貌的聚苯胺膜都具有很大的比表面积和良好的导电性能,其中,管-片状聚苯胺的膜层阻抗最小,导电性能最好.     

质子酸掺杂聚苯胺固相微萃取涂层的电化学制备及其萃取性能

考察了质子酸种类对电聚合聚苯胺涂层微观结构和萃取性能的影响.在含0.1～0.2 mol/L苯胺的H2SO4, HCl, HNO3, HClO4及H3PO4溶液中,用循环伏安法在铂丝表面聚合得到掺杂不同质子酸的聚苯胺固相微萃取头.用扫描电镜对所得萃取头的微观结构进行表征;在优化条件(0.35 g/mL NaCl, 50 ℃萃取30 min)下,以7种芳环化合物为模拟分析物,用气相色谱法测试其萃取性能.结果表明: 在HNO3和HClO4溶液中聚合得到的聚苯胺涂层具有均匀的多孔结构、平滑的膜表面和较高的萃取效率,适于芳环化合物的高效萃取.     

聚合介质酸度对聚苯胺的结构和性能的影响

不论电化学还是化学聚合,酸度对聚苯胺(PAn)的合成都有很大影响,说明只有在酸性条件下才能合成电活性的聚苯胺,鉴于聚合介质的酸度对聚苯胺的影响尚无详细的报道,本文研究了聚合介质酸度对聚苯胺的结构和性能的影响.     

Modulation of Electrochemical Oscillations by Specific Adsorption of Cl^— during the Electrooxidation of Methanol on Pt Electrode

Potential oscillation during the electrocatalytic oxidation of methanol can be modulated by the specific adsorption of Cl^- on the platinum electrode, which suppresses the electrocatalytic oxidation of methanol, and makes the cross cycle in the cyclic voltammogram become smaller and finally disappear with the increase of Cl^- concentration. The method is also applicable to the electrocatalytic oxidation of other small organic molecules.     

Synthesis of a Copper-Containing Catalyst for Electrocatalytic Oxidation of Volatile Organic Compounds

The synthesis of a copper-containing catalyst for electrocatalytic oxidation of acetone in exhaust gases was studied. Data on the electrocatalytic oxidation of acetone were analyzed in relation to the CuO content.     

Influence of Preparation Conditions on Properties of a Copper-Containing Catalyst for Electrocatalytic Oxidation of Acetone

Stages of synthesis of a copper-containing catalyst for electrocatalytic oxidation of acetone in waste gases were studied. The course of the extrusion and calcination and their influence on electrocatalytic oxidation of acetone on the catalyst synthesized were analyzed.     

Electrocatalytic selective oxidation of ethylene glycol: A concise review of catalyst development and reaction mechanism with comparison to thermocatalytic oxidation process

As an important water and seawater degradable plastic monomer, glycolic acid can be synthesized by selective oxidation of ethylene glycol. This review recapitulates recent advances in electrocatalytic ethylene glycol oxidation reaction (EGOR) from the aspects of catalytic performance and reaction mechanism. For catalytic performance evaluation, target product yield and space-time yield are correlated and analyzed for electrocatalytic and thermocatalytic EGOR systems. To elucidate the rationale behind the electrocatalytic selective oxidation of ethylene glycol, previous works using in situ Fourier transform infrared spectroscopy, online differential electrochemical mass spectrometry, ion chromatography, and theoretical calculations to investigate EGOR are systematically reviewed. Finally, the advantages of electrocatalytic EGOR are summarized by comparing electrocatalytic and thermocatalytic processes.     

Electrocatalytic oxidation of methanol at platinum electrode modified with Eu-Fe cyanide-bridged binuclear complexes

<正>The electrocatalytic oxidation of methanol at the platinum electrode modified with Eu-Fe cyanide-bridged binuclear complexes (Eu-Fe film) was investigated for the first time by cyclic voltammetry.Compared with the bare platinum electrode,the results showed that the modified electrode had excellent electrocatalytic activity for the oxidation of methanol;the oxidation peak potential shifted more negatively and the peak current increased about twenty times.The electrooxidation of methanol at the modified electrode with Eu-Fe cyanide-bridged binuclear complexes material exhibited the better tolerance capacity to poison of intermediate species;the peak current was proportional to the concentration of methanol in the range of 0.5-2.0mol/L (R~2 = 0.9991,n =7),which was a comparatively wider linear range.Moreover,based on the linear relationship between the peak current and the square root of scan rate,electrocatalytic oxidation process of methanol was confirmed to be a diffusion control process.Furthermore,according to the counting of electron transfer number(n_α) in the rate-limiting step and the slope of linear equation between acidity of electrolyte and the oxidation peak potential(E_p),the possible mechanism of the electrooxidation of methanol at the modified electrode was primarily discussed.     

Pd/TiC-C催化剂对甲酸氧化的电催化性能

研究了TiC和C作混合载体的Pd(Pd/TiC-C)催化剂对甲酸氧化的电催化性能。发现Pd/TiC-C催化剂对直接甲酸燃料电池(DFAFC)中甲酸氧化的电催化性能要优于Pd/C催化剂。而且,Pd/TiC-C催化剂的电催化性能与C和TiC的质量比有关,当质量比为2时,Pd/TiC-C催化剂对甲酸氧化的电催化活性和稳定性最好,甲酸在C和TiC的质量比为2的Pd/TiC-C催化剂电极上的氧化峰峰电位为0.164 V,比在Pd/C催化剂电极上负移12 mV,峰电流密度为23.08 mA/cm2,比在Pd/C催化剂电极上高约42％。     

单核和双核钌配合物在铟锡氧化物电极上的电化学行为及对双酚A的催化氧化

本文应用循环伏安法和微分脉冲伏安法研究了两种新型单、双核多吡啶钌(Ⅱ)配合物在铟锡氧化物(ITO)电极上的电化学行为及对双酚A(BPA)的催化氧化。研究结果表明,单、双核配合物在ITO电极上均出现两个归属为中心离子和亚胺基的氧化波,双核配合物的峰电流约为单核的2倍,表现为通过桥联配体在两中心离子间的电子转移速度较其与电极间的大。同时,两种配合物对BPA的氧化呈现相近的催化氧化活性。此外,讨论了pH值对单、双核钌配合物电化学行为的影响,比较分析了它们对BPA的催化氧化过程。     

Pt-Mo电极上CO、甲醛和甲醇的电催化氧化-微分电化学质谱研究

利用微分电化学质谱（DEMS）研究了Mo修饰的Pt电极上CO、甲醛和甲醇的电催 化氧化，证实了Mo(IV)是催化活性样品，而且它只对弱吸附CO的氧化起催化作用， 对强吸附CO的氧化没有催化活性。在低于0.4 V的电位下，吸附在Pt电极上的Mo结 甲醇和甲醛的催化氧化是通过弱吸附CO的氧化路径进行的。     

Behavior of 2',4',5',7'-Tetrabromofluorescein on a Platinum Electrode at Anodic Polarization in Aqueous Solution, Simulating Electrolytic Breakdown of Dioxins

Electrocatalytic systems are effective means for breakdown of pollutants in aqueous solution. 2',4',5',7'-Tetrabromofluorescein (eosin) is a convenient model compound for simulation of electrocatalytic oxidation of dioxins. Adsorption of eosin on platinum at potentials exceeding the oxygen evolution potential was discovered. The adsorbate orientation on platinum is presumably planar. The kinetics of electrocatalytic oxidation of eosin in aqueous solution were studied; the reaction orders, rate constants, half-lives, and activation energy were determined. Eosin is oxidized to mineral products (carbonates, bromates). Schemes of the electrocatalytic oxidation of the substrates were suggested.     

一种提高铂电催化氧化甲酸性能的简单方法

在离子液体1-乙基咪唑三氟乙酸盐(HElmTfa)中,采用循环伏安法在铂电极表面修饰聚吡咯(PPY),制得PPy-HEImTfa/Pt,并研究了其对甲酸的电催化氧化性能.与相同条件下的铂基底电极相比,PPy-HEImTfa/Pt对甲酸的电催化氧化性能有很大的提高.原位红外光谱表明,PPy-HElmTfa能降低中间体CO等对铂电极的毒化作用,促进甲酸直接氧化生成CO_2.