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Icosahedral Pt–Ni Nanocrystalline Electrocatalyst: Growth Mechanism and Oxygen Reduction Activity
Author(s) -
Tian Renxiu,
Shen Shuiyun,
Zhu Fengjuan,
Luo Liuxuan,
Yan Xiaohui,
Wei Guanghua,
Zhang Junliang
Publication year - 2018
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201800074
Subject(s) - electrocatalyst , nanocrystalline material , nucleation , materials science , icosahedral symmetry , chemical engineering , dissolution , catalysis , nanostructure , nanocrystal , alloy , bimetallic strip , crystallography , nanotechnology , chemistry , electrochemistry , metallurgy , electrode , biochemistry , organic chemistry , engineering
Engineering the structure of Pt alloy offers an effective way to the design of high performance electrocatalysts. Herein, we synthesize a sandwich‐structured, icosahedral Pt 2.1 Ni catalyst through a hot injection method. Its growth involves three steps: 1) burst nucleation of Pt atoms to form a Pt‐enriched core, 2) heterogeneous nucleation of Ni atoms onto the Pt core to form a Ni‐enriched interlayer, and 3) kinetic controlled growth of a Pt‐enriched shell. The Pt‐enriched core protects the nanostructure from collapse and mitigates the strain change caused by lattice mismatch, and thus enhances the stability of the structure. The Ni‐enriched interlayer induces the electronic modification of the outermost Pt shell, and in turn tunes the activity. The Pt‐enriched shell provides more active sites through the exposure of (1 1 1) facets and retards the dissolution of Ni atoms. As a result, this sandwich‐structure enables impressive electrocatalytic activity (0.91 mA cm −2 and 0.32 Am g P t - 1@ 0.9 V) and duability.