Particle Size Effect of Pt/C Catalyst for Oxygen Reduction in Proton Exchange Membrane Fuel Cells
Proton exchange membrane fuel cells (PEMFCs) are ideal energy conversion devices for our green future. Catalyzed by Pt nanoparticles immobilized on carbon (Pt/C), the hydrogen fuel is electrochemically converted into water, producing electricity with high efficiency. Pt particle size is one of the key factors that determine both the activity and the durability of the Pt/C electrocatalyst. We successfully prepared a series of Pt/C electrocatalysts with various average Pt particle sizes and characterized them at the cathode of PEMFCs. We reveal that both the electrocatalyst surface specific activity and the electrochemical stability improve with an increased Pt particle size, but the mass specific activity reaches the maximum value when the Pt particle size is between 4-5 nm. The reduced occupation of corner and edge atoms on the Pt particle surface is believed to weaken the adsorption of the oxygenated species on Pt, and thereafter releases more available active sites and also renders the Pt surface a stronger resistance against electrochemical corrosion. Therefore, we propose 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.
proton exchange membrane fuel cells Pt/C particle size activity durability
Zhuang Xu Huamin Zhang Hexiang Zhong Dangsheng Su
Division of Energy Storage, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalia Division of Energy Storage, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalia Shenyang National Laboratory of Materials Science, Institute of Metal Research, Chinese Academy of S
国际会议
大连
英文
41-42
2012-05-28（万方平台首次上网日期，不代表论文的发表时间）