Defect-Mediated Gold Substitution Doping in ZnO Mesocrystals and Catalysis in CO Oxidation

Ming Han Liu, Yun Wen Chen, Xiaoyan Liu, Jer Lai Kuo, Ming Wen Chu, Chung Yuan Mou

Research output: Contribution to journalArticlepeer-review

45 Citations (Scopus)

Abstract

Highly dispersed supported gold with strong metal-support interaction is a desirable material for heterogeneous catalysis. Unlike current dispersion strategies of depositing gold from solution to support, we report herein a new method of producing highly dispersed gold clusters on ZnO mesocrystal. The gold clusters appeared on defect-rich twin-brush ZnO mesocrystals (TB-ZnO) via an in-and-out process: (i) a mixed Au/Zn oxide was formed first after deposition-precipitation of Au with AuCl4-, (ii) fine Au clusters grow from the underneath to the surface of the oxide after heating. The TB-ZnO behaved like a sponge allowing gold atoms to heavily disperse into the wurtzite structure of ZnO with Zn-substitution by gold. After mild thermal treatment, the embedded gold emerged from underneath of the ZnO support to form highly dispersed Au nanoparticles of ∼2 nm on the ZnO surface. DFT calculation shows energetically favored Au-doping in TB-ZnO and facile defect-mediated migration of Au in it. The material (Au/TB-ZnO) gave outstanding activities for the catalysis of CO oxidation. The use of mesocrystals of metal oxide as supports, with rich vacancy defects, provides a new route for preparing highly dispersed and active supported metal catalysts.

Original languageEnglish
Pages (from-to)115-122
Number of pages8
JournalACS Catalysis
Volume6
Issue number1
DOIs
Publication statusPublished - Jan 4 2016
Externally publishedYes

Keywords

  • catalysis
  • CO oxidation
  • defect
  • gold
  • mesocrystal
  • substitution
  • ZnO

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)

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