Defect-Dominated Shape Recovery of Nanocrystals: A New Strategy for Trimetallic Catalysts

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• 作者：Yuen Wu ; Dingsheng Wang ; Xiaobin Chen ; Gang Zhou ; Rong Yu ; Yadong Li
• 刊名：The Journal of the American Chemical Society
• 出版年：2013
• 出版时间：August 21, 2013
• 年：2013
• 卷：135
• 期：33
• 页码：12220-12223
• 全文大小：301K
• 年卷期：v.135,no.33(August 21, 2013)
• ISSN：1520-5126

文摘

Here we present a shape recovery phenomenon of Pt鈥揘i bimetallic nanocrystals that is unequivocally attributed to the defect effects. High-resolution electron microscopy revealed the overall process of conversion from concave octahedral Pt₃Ni to regular octahedral Pt₃Ni@Ni upon Ni deposition. Further experiments and theoretical investigations indicated that the intrinsic defect-dominated growth mechanism allows the site-selective nucleation of a third metal around the defects to achieve the sophisticated design of trimetallic Pt₃Ni@M core鈥搒hell structures (M = Au, Ag, Cu, Rh). Consideration of geometrical and electronic effects indicated that trimetallic atomic steps in Pt₃Ni@M could serve as reactive sites to significantly improve the catalytic performance, and this was corroborated by several model reactions. The synthesis strategy based on our work paves the way for the atomic-level design of trimetallic catalysts.