Highly Active Nanoreactors: Patchlike or Thick Ni Coating on Pt Nanoparticles Based on Confined Catalysis

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• 作者：Xinhong Qi ; Xiangcun Li ; Bo Chen ; Huilan Lu ; Le Wang ; Gaohong He
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：January 27, 2016
• 年：2016
• 卷：8
• 期：3
• 页码：1922-1928
• 全文大小：540K
• ISSN：1944-8252

文摘

Catalyst-containing nanoreactors have attracted considerable attention for specific applications. Here, we initially report preparation of PtNi@SiO₂ hollow microspheres based on confined catalysis. The previous encapsulation of dispersed Pt nanoparticles (NPs) in hollow silica microspheres ensures the formation of Pt@Ni coreshell NPs inside the silica porous shell. Thus, the Pt NPs not only catalyze the reduction of Ni ions but also direct Ni deposition on the Pt cores to obtain Pt@Ni core–shell catalyst. It is worthy to point out that this synthetic approach helps to form a patchlike or thick Ni coating on Pt cores by controlling the penetration time of Ni ions from the bulk solution into the SiO₂ microspheres (0.5, 1, 2, or 4 h). Notably, the Pt@Ni core–shell NPs with a patch-like Ni layer on Pt cores (0.5 and 1 h) show a higher H₂ generation rate of 1221–1475 H₂ mL min^–1 g^–1_cat than the Pt@Ni NPs with a thick Ni layer (2 and 4 h, 920–1183 H₂ mL min^–1 g^–1_cat), and much higher than that of pure Pt NPs (224 H₂ mL min^–1 g^–1_cat). In addition, the catalyst possesses good stability and recyclability for H₂ generation. The Pt@Ni core–shell NPs confined inside silica nanocapsules, with well-defined compositions and morphologies, high H₂ generation rate, and recyclability, should be an ideal catalyst for specific applications in liquid phase reaction.