Carbon-supported Pd-Fe electrocatalysts for oxygen reduction reaction (ORR) and their methanol tolerance
Carbon-supported Pd-Fe electrocatalysts for oxygen reduction reaction (ORR) and their methanol tolerance
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DOI：
10.1016/j.jelechem.2011.04.016
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发表时间：
2011-07-15
影响因子：
4.5
通讯作者：
Rahul, R.
中科院分区：
文献类型：
--
作者：
Neergat, M.;Gunasekar, V.;Rahul, R.
在无稳定剂的碱性介质中，采用低温一步共还原法制备了不同Pd/Fe比(1：1、2：1、3：1)的碳负载钯-铁双金属电催化剂。用X射线衍射仪和透射电子显微镜对催化剂进行了物理表征。采用欠电位沉积法(UPD)对氢和铜进行了电化学表征。考察了氧还原反应(ORR)的电催化活性，并与标准铂碳催化剂进行了比较。碳负载的Pd-Fe双金属催化剂比纯Pd/C具有更高的比表面积，在氧饱和0.1MHClO4溶液中，所制备的Pd-Fe双金属催化剂的ORR半波电位比Pd/C正移了75-100 mV。Pd3Fe/C-催化剂的催化活性最高，与标准的铂/C催化剂相近，X射线衍射峰位置没有明显的变化。在甲醇存在下，碳负载的Pd和Pd-Fe双金属催化剂表现出比铂/C更好的ORR选择性和活性。Pd3Fe/C是最好的Pd基电催化剂，其过氧化氢生成量与在铂/C上相当。这些催化剂是在低温下制备的，没有任何进一步的热处理，其活性不受高温下可能发生的晶粒度、偏析和贵金属含量的影响。(C)2011爱思唯尔B.V.保留所有权利。
Carbon-supported palladium-iron bimetallic electrocatalysts of different Pd to Fe ratios (1:1, 2:1, 3:1) were prepared by a low temperature single step co-reduction method in alkaline media without any stabilizing agents. The physical characterizations of catalysts were done using XRD and TEM. The electrochemical characterizations were done using underpotential deposition (upd) of hydrogen and copper. Electrocatalytic activities for oxygen reduction reaction (ORR) were investigated and compared to that of standard Pt/C catalyst. The carbon-supported Pd-Fe bimetallic catalysts showed higher surface area than that of pure Pd/C. The half-wave potential of ORR on as-prepared palladium-iron bimetallic catalysts was shifted positively by similar to 75-100 mV from that of Pd/C in oxygen saturated 0.1 M HClO4 solution. The highest catalytic activity was obtained with Pd3Fe/C - catalyst and it was close to that of standard Pt/C. XRD analysis did not show any noticeable shift in peak position due to alloying. In presence of methanol, carbon-supported Pd and Pd-Fe bimetallic catalysts showed superior ORR selectivity and activity unlike Pt/C. The peroxide generation on Pd3Fe/C - the best of Pd based electrocatalyst - was comparable to that on Pt/C. These catalysts, prepared at low temperature and without any further heat-treatment, gave activities that were free from effects of crystallite size, segregation, and enrichment of precious metal content that might happen at high temperature. (C) 2011 Elsevier B.V. All rights reserved.