Morphology-dependent structures and catalytic performances of Au nanostructures on Cu₂O nanocrystals synthesized by galvanic replacement reaction

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• 作者：Zhenhua Zhang ; Rui Song ; Tian Cao ; Weixin Huang ; ^{huangwx@ustc.edu.cn}
• 关键词：Au/Cu2O nanocomposites ; Galvanic replacement reaction ; Liquid&ndash ; solid interfacial reaction ; Crystal plane effect ; Aerobic oxidation of benzyl alcohol
• 刊名：Journal of Energy Chemistry
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：25
• 期：6
• 页码：1086-1091
• 全文大小：1672 K
• 卷排序：25

文摘

Au nanostructures were prepared on uniform Cu2O octahedra and rhombic dodecahedra via the galvanic replacement reaction between HAuCl4 and Cu2O. The compositions and structures were studied by Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), High-Resolution Transmission Electron Microscope (HRTEM), X-Ray Diffraction (XRD), X-Ray Absorption Spectroscopy (XAS), X-ray Photoelectron Spectroscopy (XPS) and in-situ DRIFTS spectroscopy of CO adsorption. Different from the formation of Au–Cu alloys on Cu2O cubes by the galvanic replacement reaction (ChemNanoMat 2 (2016) 861-865), metallic Au particles and positively-charged Au clusters form on Cu2O octahedra and rhombic dodecahedra at very small Au loadings and only metallic Au particles form at large Au loadings. Metallic Au particles on Cu2O octahedra and rhombic dodecahedra are more active in catalyzing the liquid phase aerobic oxidation reaction of benzyl alcohol than positively-charged Au clusters. These results demonstrate an obvious morphology effect of Cu2O nanocrystals on the liquid–solid interfacial reactions and prove oxide morphology as an effective strategy to tune the surface reactivity and catalytic performance.