Title of Paper:Preparation of hollow submicrospheres with ordered porous SiO2 shell and multiple AuPt nanoalloy cores and their high catalytic activity

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Date of Publication:2016-01-15

Journal:CHEMICAL ENGINEERING JOURNAL

Included Journals:SCIE、EI

Volume:284

Issue:284

Page Number:351-356

ISSN No.:1385-8947

Key Words:Noble metal nanocrystals; Hollow silica submicrospheres; Mesopore; Catalyst

Abstract:Noble metal nanocrystals (Au, Pt or AuPt) with controlled compositions and nanostructures were embedded into hollow silica submicrospheres with highly ordered radial mesopores through a one-step sol-gel process. 2,4-Dihydroxybenzoic acid-formaldehyde (RF-COOH) resin submicrospheres were utilized simultaneously as a hard template to create hollow interiors inside the silica submicrospheres and as carriers to transport pregrown metal nanocrystals, including Au nanoparticle (NP), Pt NP, and AuPt nanoalloy, into the submicrospheres. Calcination removes the resin submicrospheres and causes metal nanocrystals embedded into the RF-COOH submicrospheres break into multiple smaller nanoparticles (2-6 nm) that are randomly dispersed in the hollow space of SiO2 submicrospheres M@SiO2 (M = Au, Pt or AuPt). The AuPt@SiO2 submicrospheres showed good catalytic performance for epoxidation of styrene with the conversion and selectivity of 74% and 85%, respectively. The approach reported in this study could potentially be used to simplify the fabrication process of noble metal nanoalloys, which usually entails multiple steps and a previously synthesized hard metal template, and thus guide the design and creation of high-performance catalysts. (C) 2015 Elsevier B.V. All rights reserved.