Carbon-supported PdM (M = Au and Sn) nanocatalysts for the electrooxidation of ethanol in high pH media
Carbon-supported PdM (M = Au and Sn) nanocatalysts for the electrooxidation of ethanol in high pH media
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DOI：
10.1016/j.jpowsour.2008.11.065
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发表时间：
2009-02-15
影响因子：
9.2
通讯作者：
Laufek, Frantisek
中科院分区：
文献类型：
--
作者：
He, Qinggang;Chen, Wei;Laufek, Frantisek
采用化学还原法制备了碳载Pd 4Au和Pd 2. 5Sn合金纳米粒子，并通过质谱、透射电子显微镜和X射线衍射等实验技术对其进行了表征。在碱性介质中，采用循环伏安法、计时电流法和交流阻抗法研究了乙醇在合成催化剂和商品Pt/C上的电氧化行为。伏安法和计时电流法的测量结果表明，更高的电流密度和更长的时间稳定性，乙醇氧化的钯合金纳米催化剂比商业之一。采用电化学阻抗谱和塔菲尔图研究了乙醇电氧化的电荷转移动力学。结果表明，虽然反应动力学可能是有点更缓慢的Pd基合金催化剂比商业Pt/C，前者似乎有更高的耐受性表面中毒。总的来说，Pd基合金催化剂是乙醇电催化氧化的理想催化剂，其中Pd 4Au/C对乙醇在碱性介质中的电催化氧化具有最好的催化活性。(C)2008 Elsevier B. V.保留所有权利。
Carbon-supported Pd4Au- and Pd2.5Sn-alloyed nanoparticles were prepared by a chemical reduction method, and characterized by a wide array of experimental techniques including mass spectrometry, transmission electron microscopy, and X-ray diffraction spectroscopy. Ethanol electrooxidation on the as-synthesized catalysts and commercial Pt/C was then investigated and compared in alkaline media by cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy Studies at room temperature. Voltammetric and chronoamperometric measurements showed higher current density and longer term stability in ethanol oxidation with the palladium alloy nanocatalysts than with the commercial one. Electrochemical impedance spectroscopy and Tafel plots were employed to examine the charge-transfer kinetics of ethanol electrooxidation. The results suggest that whereas the reaction kinetics might be somewhat more sluggish on the Pd-based alloy catalysts than on commercial Pt/C, the former appeared to have a higher tolerance to surface poisoning. Overall, the Pd-based alloy catalysts represent promising candidates for the electrocatalytic oxidation of ethanol, and Pd4Au/C displays the best catalytic activity among the series for the ethanol oxidation in alkaline media. (C) 2008 Elsevier B.V. All rights reserved.