title: In-situ loading ultrafine AuPd particles on ceria: highly active catalyst for solvent-free selective oxidation of benzyl alcohol.
abstract: Ce(III) oxide was synthesized under the protection of nitrogen gas, which had strong ability to reduce noble metal ions (e.g., Au, Pd ions) into metallic forms under oxygen-free conditions. On the basis of the surface redox reaction between the Ce(III) oxide support and noble metal ions, an effective and novel approach was presented to prepare noble metal/CeO(2) nanocatalysts, and a series of AuPd/CeO(2) nanocomposites with different Au:Pd molar ratios and metal loadings were obtained in the absence of any extra reducing and protective agents. The resultant composites were characterized by different techniques including X-ray diffraction, transmission electron microspectroscopy, X-ray photoelectron microspectroscopy, and ICP-AES analysis. It was demonstrated that in the AuPd/CeO(2) composites the content of Ce(III) reached about 30%, and the AuPd bimetallic particles with average size of 2.6 or 3.3 nm and narrow size distribution were uniformly distributed on the CeO(2) nanorods. The AuPd/CeO(2) composites were found to be excellent heterogeneous nanocatalysts for the selective oxidation of benzyl alcohol under solvent-free conditions. It was shown that all the AuPd/CeO(2) catalysts exhibited good selectivity toward benzaldehyde; especially, the catalyst with Au:Pd = 1:5 and metal loading of 1.2 wt % displayed extremely high activity with a TOF = 30.1 s(-1) at 160 °C.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Hongye
authors.initials: H
authors.lastname: Zhang
authors.forename: Yun
authors.initials: Y
authors.lastname: Xie
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Sun
authors.forename: Ranting
authors.initials: R
authors.lastname: Tao
authors.forename: Changliang
authors.initials: C
authors.lastname: Huang
authors.forename: Yanfei
authors.initials: Y
authors.lastname: Zhao
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Liu