title: SiO2-Ag-SiO2core/shell structure with a high density of Ag nanoparticles for CO oxidation catalysis.
abstract: SiO2-Ag-SiO2, a sandwiched core/shell structure with a layer of Ag nanoparticles (∼4 nm) encapsulated between a shallow SiO2surface layer and a SiO2submicrosphere substrate (∼200 nm), has been synthesized from [Formula: see text] and SiO2spheres by a facile one-pot hydrothermal method. The composite is proposed to result from the dynamic balance between the [Formula: see text] reduction and the dissolution-redeposition of SiO2in mild basic media. The synthetic mechanism and the roles of the reaction time, temperature, and the amount of ammonia in the formation of this unique structure are investigated and discussed. The composite structure shows superior catalytic performance in CO oxidation to the control Ag/SiO2structure prepared by impregnation. Pre-treatment by O2at 600 °C significantly improves the catalytic performance of the composite structure and preserves the nanocomposite structure well.
authors.affiliation: State Key Laboratory for Metallic Matrix Composite Materials, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China.
authors.forename: Xiaoqian
authors.initials: X
authors.lastname: Feng
authors.forename: Hongmo
authors.initials: H
authors.lastname: Li
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhang
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Song
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.forename: Liping
authors.initials: L
authors.lastname: Zhao
authors.forename: Lian
authors.initials: L
authors.lastname: Gao