Effect of particle size on the activity and durability of the Pt/C electrocatalyst for proton exchange membrane fuel cells
Effect of particle size on the activity and durability of the Pt/C electrocatalyst for proton exchange membrane fuel cells
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DOI：
10.1016/j.apcatb.2011.10.007
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发表时间：
2012-01-12
影响因子：
22.1
通讯作者：
Su, Dangsheng
中科院分区：
文献类型：
--
作者：
Xu, Zhuang;Zhang, Huamin;Su, Dangsheng
在质子交换膜燃料电池（PEMFC）阴极上原位制备了平均粒径为3 ~ 6.5nm的碳载Pt（Pt/C）催化剂，并对其进行了表征。一个明确的Pt颗粒尺寸上的催化活性的氧还原反应（ORR）和电催化剂的耐久性的影响被揭示。随着Pt粒径的增大，Pt/C的表面比活性和电化学稳定性均有所提高，但Pt/C的质量比活性与电化学比表面积的损失相平衡。在Pt颗粒尺寸增加期间，Pt表面上的角和边缘原子的减少的占据被认为减弱了含氧物质在Pt上的吸附，并且此后释放更多的用于ORR的可用活性位点，并且还使得Pt表面对电势循环具有更强的抵抗力。因此，建议通过设计表面具有更多面原子的Pt微结构，将开发具有改善的活性和增强的耐久性的PEMFC阴极电催化剂。(C)2011爱思唯尔有限公司版权所有。
Carbon supported Pt (Pt/C) with various average particle sizes ranging from sub 3 nm to 6.5 nm were in situ prepared and characterized at the cathode of proton exchange membrane fuel cells (PEMFCs). A clear Pt particle size effect on both the catalytic activity for oxygen reduction reaction (ORR) and the durability of the electrocatalyst was revealed. With the Pt particle size increase, both the surface specific activity and the electrochemical stability of Pt/C improved; however, the mass specific activity of Pt/C is balanced by the electrochemical surface area loss. The reduced occupation of corner and edge atoms on the Pt surface during the Pt particle size increase is believed to weaken the adsorption of the oxygenated species on Pt, and thereafter releases more available active sites for ORR and also renders the Pt surface a stronger resistance against potential cycling. It is therefore proposed that by designing the Pt microstructure with more face atoms on the surface, cathode electrocatalyst with both improved activity and enhanced durability would be developed for PEMFCs. (C) 2011 Elsevier B.V. All rights reserved.