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

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Date of Publication:2016-01-27

Journal:ACS APPLIED MATERIALS & INTERFACES

Included Journals:SCIE、EI、PubMed

Volume:8

Issue:3

Page Number:1922-1928

ISSN No.:1944-8244

Key Words:Pt@Ni nanoparticles; core-shell; nanoreactor; hydrogen generation: catalysis

Abstract: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 H-2 generation rate of 1221-1475 H-2 mL min(-1) g(cat)(-1) than the Pt@Ni NPs with a thick Ni layer (2 and 4 h, 920-1183 H-2 mL min(-1) g(cat)(-1)), and much higher than that of pure Pt NPs (224 H-2 mL min(-1) g(cat)(-1)). In addition, the catalyst possesses good stability and recyclability for H-2 generation. The Pt@Ni core-shell NPs confined inside silica nanocapsules, with well-defined compositions and morphologies, high H-2 generation rate, and recyclability, should be an ideal catalyst for specific applications in liquid phase reaction.