(23d) Synthesis and Characterization of Homogeneous-Distributed Platinum Nanoparticles from Block Copolymer Template for Membrane Electrode

Due to the scarcity of platinum (Pt) resources, the Pt amount will seriusly limit the development of fuel cells for commercial applications, while the excellent catalytic performance of Pt nanoparticle catalyst makes it impossible to be totally replaceed in the short term.[1] To resolve the conflicting issue, both the availability and the durability of Pt nanoparticle catalyst need to improve significantly and Pt loading need to be reduced sharply. Pt-based alloy catalysts is the feasible way to improve the availability of Pt nanoparticle catalyst by optimizing the bonding energy for oxygen atom and reducing the Pt amount simultaneously.[2-7] However, a method to achieve the highly durable Pt catalyst needs still be explored. One of the main reasons is that the problem of nonuniform distribution of Pt NPs remains unsolved, thus leads to a high possibility for nanoparticle aggregation on the surface of support materials. Unfortunately, most of the existing technologies for synthesis of Pt nanoparticle catalyst, such as electrodeposition, microwave-assisted process and thermal reduction, can not achieve the homogeneous distribution of Pt NP catalyst successfully.[8]

Self-assembly of block copolymers (BCs) to form nano-structured templates has been considered as one of the most important methodology for preparation of functional and homogeneous-distributed nanopatterns.[9-12] However, up to now, the preparation and electrochemical testing of homogeneous-distributed Pt nanoparticle arrays from BCs for fuel cells have less been reported, let alone the investigation of the advances of durability in fuel cell application. In this work, homogeneous-distributed arrays of Pt nanoparticle catalysts have been obtained through a block copolymer route, and we will present herein (i) a detailed characterization of the structure of the Pt nanoparticle s and the spacing of the arrays, and (ii) a comprehensive study of the stability and longevity of the homogeneous-distributed Pt nanoparticle arrays loaded on different catalyst supports for the application of fuel cell.

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