Carbon-supported Pd-Ag catalysts with silica-coating layers as active and durable cathode catalysts for polymer electrolyte fuel cells
Carbon-supported Pd-Ag catalysts with silica-coating layers as active and durable cathode catalysts for polymer electrolyte fuel cells
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DOI：
10.1016/j.ijhydene.2017.06.046
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发表时间：
2017-07
影响因子：
7.2
通讯作者：
Kayoung Park;H. Matsune;M. Kishida;S. Takenaka
中科院分区：
文献类型：
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作者：
Kayoung Park;H. Matsune;M. Kishida;S. Takenaka
采用过渡金属对聚合物电解质燃料电池（PEFCs）中氧还原反应（ORR）用碳负载钯催化剂（Pd/CBs）进行改性，以提高其催化活性。在乙二醇（EG）存在下，用nabh4还原金属前驱体制备Pd-M/CB(N) （M = Co, Cu， Y, Ag）。Pd- ag /CB(N)对ORR的催化活性最高，是Pd/CB的2倍。与传统浸渍法制备的Pd-Ag/CB(I)相比，Pd-Ag/CB(N)具有更高的ORR活性，因为其形成的Pd-Ag合金颗粒较小，直径为1 ~ 2 nm。在Pd-Ag/CB(N)表面覆盖二氧化硅层（SiO2/Pd-Ag/CB(N)），以提高其在恶劣阴极条件下的耐久性。SiO2/Pd-Ag/CB(N)对ORR具有较高的催化活性，因为二氧化硅层阻止了催化剂中金属物质的扩散。
Carbon-supported Pd catalysts (Pd/CBs) for oxygen reduction reaction (ORR) in polymer electrolyte fuel cells (PEFCs) were modified with transition metals to enhance their catalytic activity. Pd-M/CB(N) (M = Co, Cu, Y, and Ag) was prepared by the reduction of metal precursors with NaBH4in the presence of ethylene glycol (EG) without heat treatment. Pd-Ag/CB(N) showed the highest catalytic activity for the ORR among all the Pd-based catalysts tested in the present study, and it had twice higher activity than Pd/CB. The Pd-Ag/CB(N) also had the higher ORR activity than the Pd-Ag/CB prepared by a conventional impregnation method (Pd-Ag/CB(I)) due to the formation of smaller Pd-Ag alloy particles with 1–2 nm diameters. Pd-Ag/CB(N) was covered with silica layers (SiO2/Pd-Ag/CB(N)) in order to improve their durability under severe cathode conditions. The SiO2/Pd-Ag/CB(N) had high catalytic activity for the ORR during the durability test because silica layers prevented the diffusion of metal species from the catalysts.