枝状银-钯复合材料的制备及电催化氧化乙醇性能研究

发布时间：2018-03-14 00:02

本文选题：乙醇氧化　切入点：电催化　出处：《稀有金属》2017年06期 　论文类型：期刊论文

【摘要】：通过电沉积法在碳纸表面制备了枝状银微纳结构(Ag-Fr),再利用电置换反应(GRR),在枝状银表面置换上一层钯元素,形成枝状银-钯复合材料(Ag_xPd_y-Fr)。所得复合材料的形貌和成分经过粉末X射线衍射(XRD)、扫描电镜(SEM)、电感耦合等离子体原子发射光谱(ICPOES)等手段表征。利用电化学方法研究了枝状银-钯复合材料Ag_xPd_y-Fr在碱性条件下对乙醇的电催化氧化活性,并与与商业Pd/C催化剂进行了比较。通过对比,在制备的几种催化剂中,Ag_(94)Pd_6-Fr在碱性条件下对乙醇的电催化氧化活性最高。由电催化氧化乙醇(EOR)的循环伏安(CVs)研究可知,乙醇在Ag_(94)Pd_6-Fr上的正向扫描氧化峰电流密度最高,为~33 m A·cm~(-2),约为Pd/C上的11倍,且起始峰电位约比Pd/C上的低0.08 V。乙醇在Ag_(91)Pd_9-Fr和Ag_(87)Pd_(13)-Fr上的正向扫描氧化峰电流密度分别为Pd/C上的9.3倍和5.4倍,起始峰电位分别比Pd/C上的低0.06和0.01 V。当置换时间超过2 h后,枝状结构的细微结构消失,整个结构间的空隙变小,比表面积减小,加上表面AgCl沉淀的生成和覆盖,虽然此时枝状复合材料的钯含量增,但电催化活性较低。
[Abstract]:The dendritic silver micro-nano structure (Ag-Fran) was prepared on the surface of carbon paper by electrodeposition. A palladium element was replaced on the dendritic silver surface by electroreplacement reaction (GRRN). The morphology and composition of the composite were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and inductively coupled plasma atomic emission spectrometry (ICPOESs). The electrocatalytic oxidation activity of dendritic silver palladium composite Ag_xPd_y-Fr for ethanol under alkaline conditions. Compared with commercial Pd/C catalysts, the electrocatalytic oxidation of ethanol was the highest in the prepared catalysts. The results showed that the electrocatalytic oxidation of ethanol by cyclic voltammetry was the highest in alkaline condition, and the cyclic voltammetric voltammetry (CV) of the electrocatalytic oxidation of ethanol-eor was obtained by using cyclic voltammetric voltammetry (CV), and the results showed that the electrocatalytic oxidation of ethanol was the highest in alkaline condition. The peak current density of the forward scan oxidation peak of ethanol on Ag_(94)Pd_6-Fr was the highest, which was 33 Ma 路cm ~ (-2), about 11 times of that on Pd/C, and the initial peak potential was about 0.08 V lower than that on Pd/C. The current density of the forward scanning oxidation peak of ethanol on Ag_(91)Pd_9-Fr and Ag_(87)Pd_(13)-Fr was 9.3 and 5.4 times of that on Pd/C, respectively, and the peak current density of ethanol on Ag_(91)Pd_9-Fr and Ag_(87)Pd_(13)-Fr was 9.3 times and 5.4 times higher than that on Pd/C, respectively, and the initial peak potential was 0.08V lower than that on Pd/C. The initial peak potential was 0.06 and 0.01V lower than that on Pd/C, respectively. When the replacement time was more than 2 h, the fine structure of the branched structure disappeared, the void between the whole structure became smaller, the specific surface area decreased, and the surface AgCl precipitation was formed and covered. Although the palladium content of the dendritic composites increased at this time, the electrocatalytic activity was lower.
【作者单位】：东莞理工学院生态环境与建筑工程学院;东莞理工学院广东省新型纳米材料研究与应用工程技术中心;
【基金】：国家自然科学基金项目(21475022,21505019) 广东省自然科学基金项目(2015A030310272) 广东省科技计划项目(2015B090927007) 广东省创新强校工程项目(2014KZDXM073,2014KTSCX181,2015KCXTD029)资助
【分类号】：O643.36;TM911.4

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