Chinese Journal of Catalysis ›› 2017, Vol. 38 ›› Issue (9): 1588-1596.DOI: 10.1016/S1872-2067(17)62778-5

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Top-down synthesis strategies:Maximum noble-metal atom efficiency in catalytic materials

Yaxin Chena, Zhiwei Huanga, Xiao Gub, Zhen Maa, Jianmin Chena, Xingfu Tanga,c   

  1. a Institute of Atmospheric Sciences, Shanghai Key Laboratory of Atmospheric Particle Pollution & Prevention(LAP3), Department of Environmental Science & Engineering, Fudan University, Shanghai 200433, China;
    b Department of Applied Physics, Chongqing University, Chongqing 401331, China;
    c Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology(CICAEET), Nanjing University of Information Science & Technology, Nanjing 210044, Jiangsu, China
  • Received:2016-11-29 Revised:2016-12-30 Online:2017-09-18 Published:2017-09-06
  • Contact: 10.1016/S1872-2067(17)62778-5
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (21477023), and the Science and Technology Commission of Shanghai Municipality (14JC1400400).

Abstract:

Top-down synthesis has been used to prepare catalytic materials with nanometer sizes, but fabri-cating atomically dispersed metal catalysts remains a challenge because surface single metal atoms are prone to aggregation or coalescence. A top-down strategy is used to synthesize atomically dis-persed metal catalysts, based on supported Ag nanoparticles. The changes of the geometric and electronic structures of the Ag atoms during the top-down process are studied using the in situ syn-chrotron X-ray diffraction technique, ex situ X-ray absorption spectroscopy, and transmission elec-tron microscopy. The experimental results, coupled with the density functional theory calculations, demonstrate that the electronic perturbation of the Ag frontier orbitals, induced by the Ag-O inter-actions at the perimeter of the metal-support interface, is the driving force of the top-down process. The top-down synthesis has two important functions:to increase the number of catalytic active sites and to facilitate the study of complex reaction mechanisms (e.g., formaldehyde oxidation) by developing single-site model catalysts.

Key words: Top-down synthesis, Atomic dispersion, Catalytic active site, Electronic metal-support interaction, Formaldehyde oxidation