High-Performance Dealloyed PtCu/CuNW Oxygen Reduction Reaction Catalyst for Proton Exchange Membrane Fuel Cells

详细信息    查看全文

• 作者：Jarrid A. Wittkopf ; Jie Zheng ; Yushan Yan
• 刊名：ACS Catalysis
• 出版年：2014
• 出版时间：September 5, 2014
• 年：2014
• 卷：4
• 期：9
• 页码：3145-3151
• 全文大小：462K
• ISSN：2155-5435

文摘

One major barrier to fuel cell commercialization is the high cost of oxygen reduction reaction catalysts. Current catalysts are predominantly supported Pt nanoparticles. These nanoparticles show high surface area but low specific activity and durability. A transition to unsupported catalysts possessing an extended surface would improve both specific activity and durability and in turn cost-effectiveness when high surface area can be achieved. Platinum-coated copper nanowires (Pt/CuNW) exemplify these advantages. In this study, postsynthetic processing is used to further improve the performance of Pt/CuNW catalyst. Specifically, annealing followed by electrochemical dealloying enhances activity through geometric lattice tuning. The resultant bimetallic PtCu/CuNW catalyst yields specific and mass activities (SA and MA) of 2.65 mA cm_Pt^鈥? and 1.24 A mg_Pt^鈥?, surpassing the respective Department of Energy (DOE) benchmarks of 0.72 mA cm^鈥? and 0.44 A mg_Pt^鈥?. PtCu/CuNWs demonstrate enhanced durability over Pt nanoparticle catalysts by maintaining 64.1% of its active surface area after 30鈥?00 cycles between 0.6鈥?.1 vs RHE at a scan rate of 50 mV s^鈥? in Ar saturated 0.1 M HClO₄. Post durability PtCu/CuNWs outperformed the DOE benchmarks with a SA and MA of 1.50 mA cm_Pt^鈥? and 0.477 A mg_Pt^鈥?.

Keywords:

proton exchange membrane fuel cells; ORR catalysts; bimetallic catalysts; core鈭抯hell catalysts; extended structure catalysts; dealloyed catalysts