Solving Nafion poisoning of ORR catalysts with an accessible layer: designing a nanostructured core‐shell Pt/C catalyst via a one‐step self‐assembly for PEMFC. (13th July 2020)

• Record Type: Journal Article
• Authors: Zhou, Fen; Yan, Yizhi; Guan, Shumeng; Guo, Wei; Sun, Meiling; Pan, Mu
• Is Part Of: International journal of energy research. Volume 44:Number 13(2020)
• Page Start: 10155
• Page End: 10167
• Publication Date: 2020-07-13
• Subjects: accessible layer -- core‐shell -- ORR catalyst -- proton exchange membrane fuel cell -- self‐assembly; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Power resources -- Research -- Periodicals; 621.042
• DOI: 10.1002/er.5629
• Languages: English
• ISSNs: 0363-907X

Abstract

Summary: A core‐shell Pt/C@NCL300 catalyst with an accessible layer was designed to recover lost ORR activity and was constructed via a one‐step self‐assembly process in this paper. A thin porous layer derived from Nafion was first formed on the surface of Pt/C catalyst to create a shell. This first coating successfully separated the Nafion and Pt particles in the catalysts and reducing the negative impact of Nafion on ORR activity and enhancing the fuel cell performance. The newly fabricated Pt/C@NCL300 catalyst exhibited much higher specific activity than the original Pt/C catalyst in RDE tests under the same conditions and were comparable to the activity of Pt/C electrode without Nafion poisoning. Moreover, the fuel cell with Pt/C@NCL300 catalyst exhibited a higher power density without an obvious increase in proton transport and O2 transport resistance compared to that of a Pt/C fuel cell with a low Pt loading. This result indicates that coating the Pt/C catalyst with a layer accessible for oxygen and protons is a promising way to effectively promote Pt‐based catalysts that work under normal operating conditions. Abstract : A novel way to optimize the ionomer/Pt interfacial structure to alleviate ionomer poisoning effect has been proposed. It was achieved via a porous coating derived from Nafion on Pt particles which could reduce ionomer/Pt interface and made Pt particles accessible to protons and oxygen. The new catalyst with porous coating exhibits superior ORR and better cell performance.