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论文类型：期刊论文

发表时间：2016-01-15

发表刊物：CHEMICAL ENGINEERING JOURNAL

收录刊物：SCIE、EI

卷号：284

期号：284

页面范围：351-356

ISSN号：1385-8947

关键字：Noble metal nanocrystals; Hollow silica submicrospheres; Mesopore; Catalyst

摘要：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.