A Comparative Study of Variously Prepared Carbon-Supported Pt / MoO x Anode Catalysts for a Polymer Electrolyte Fuel Cell
A Comparative Study of Variously Prepared Carbon-Supported Pt / MoO x Anode Catalysts for a Polymer Electrolyte Fuel Cell
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DOI：
10.1149/1.3223970
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发表时间：
2009-11
影响因子：
3.9
通讯作者：
E. N. Muhamad;T. Takeguchi;Feng Wang;Guoxiong Wang;T. Yamanaka;W. Ueda
中科院分区：
文献类型：
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作者：
E. N. Muhamad;T. Takeguchi;Feng Wang;Guoxiong Wang;T. Yamanaka;W. Ueda
采用预浸渍法、后浸渍法和化学还原法制备了碳载Pt/MoOx阳极催化剂。所有催化剂的物理化学特性，通过X-射线衍射，扫描透射电子显微镜，和CO脉冲滴定。CO溶出伏安法证实了CO的电化学氧化，表明大部分CO吸附在Pt位上被氧化。采用化学还原法制备的Pt/MoOx/C催化剂在纯H2中表现出上级的氢电化学氧化性能，这显然是由于Pt的粒径比其它Pt/MoOx/C催化剂小得多。而在500 ppmCO/H2混合气体中的阳极性能表明，采用后浸渍法制备的Pt/MoOx/C催化剂具有较高的CO耐受性。即使在开路条件下，水煤气变换（WGS）反应中CO的氧化也可以通过生成CO2来显示。随着电流的增加，用于WGS反应的活性位点通过氢的电化学氧化而再生。
Carbon-supported Pt/MoO x anode catalysts were prepared by the preimpregnation, postimpregnation, and chemical reduction methods. The physicochemical characteristics of all catalysts were determined by X-ray diffraction, scanning transmission electron microscopy, and CO pulse titration. The electrochemical oxidation of CO verified from CO-stripping voltammetry shows that most of the CO ads were oxidized on the Pt sites. The Pt/MoO x /C catalyst prepared by the chemical reduction method showed superior hydrogen electrochemical oxidation in pure H 2 , apparently due to the much smaller Pt particle size than those of the other Pt/MoO x /C catalysts. However, the anode performances in the presence of 500 ppm CO/H 2 mixture showed that a catalyst with high CO tolerance was derived from the Pt/MoO x /C catalyst prepared by postimpregnation method. The oxidation of CO by the water―gas shift (WGS) reaction is shown by the formation of CO 2 even under an open-circuit condition. With an increase in current, active sites for the WGS reaction is regenerated by electrochemical oxidation of hydrogen.