Effect of Synthesis Methods on Methanol Oxidation Reaction on Reduced Graphene Oxide Supported Palladium Electrocatalysts
Effect of Synthesis Methods on Methanol Oxidation Reaction on Reduced Graphene Oxide Supported Palladium Electrocatalysts
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DOI：
10.1016/j.proeng.2017.04.143
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
J. C. Ng;C. Y. Tan;B. Ong;A. Matsuda
中科院分区：
文献类型：
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作者：
J. C. Ng;C. Y. Tan;B. Ong;A. Matsuda
直接甲醇燃料电池（DMFC）已被发现是使用甲醇作为燃料的便携式电子产品的有效电源。由于甲醇的不完全氧化而形成的中间物质一氧化碳（CO）使催化剂中毒，从而导致低稳定性和甲醇氧化反应（莫尔）。钯（Pd）作为一种潜在的电催化剂出现，具有更好的耐受CO中毒，并且比目前使用的铂（Pt）电催化剂便宜。合成方法对催化剂的性能有显著影响。本研究采用微波法和水热法将Pd纳米催化剂负载到还原氧化石墨烯（rGO）上，分别命名为Pd/rGOM和Pd/rGOH。采用X射线粉末衍射（XRD）、场发射扫描电子显微镜（FESEM）结合X射线能量色散谱（EDX）和拉曼光谱（Raman）等手段研究了rGO负载Pd电催化剂（Pd/rGO）的结构和形貌。采用循环伏安法（CV）和计时电流法（CA）对催化剂的甲醇氧化活性和稳定性进行了研究。通过这两种方法合成的电催化剂在石墨烯表面上表现出均匀的负载。Pd/rGOM比Pd/rGOH具有更高的甲醇氧化活性、更大的电化学活性表面积（ECSA）和更好的稳定性，这可能是由于Pd/rGOH的粒径小得多。
Direct methanol fuel cells (DMFCs) have been found to be an efficient power source for portable electronic products that uses methanol as fuel. The intermediate species, carbon monoxide (CO) that forms owing to the incomplete oxidation of methanol poison the catalysts and thus leads to low stability and methanol oxidation reaction (MOR). Palladium (Pd) emerges as a potential electrocatalyst with better tolerance to CO-poisoning and is cheaper than the currently used platinum (Pt) electrocatalyst. Synthesis method has been reported to have prominent effect on the catalytic performance. In this study, Pd nanocatalysts were loaded on reduced graphene oxide (rGO) by two methods, the microwave and hydrothermal synthesis methods, designated as Pd/rGOMand Pd/rGOH. X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM) coupled with energy dispersive X-ray spectroscopy (EDX) and Raman spectroscopy were used to investigate the structure and morphology of rGO supported Pd electrocatalysts (Pd/rGO). The methanol oxidation activity and stability were evaluated by cyclic voltammetry (CV) and chronoamperometry (CA). Electrocatalysts synthesized by both methods showed uniform loading on the surface of graphene. Pd/rGOMshowed highermethanol oxidation activity, larger electrochemically active surface area (ECSA) and better stability over the Pd/rGOHwhich could be due to the much smaller particle size of the former electrocatalytst.