Highly active and sintering-resistant heteroepitaxy of Au nanoparticles on ZnO nanowires for CO oxidation

Jiaxin Liu, Botao Qiao, Yian Song, Hailian Tang, Yudong Huang, Jingyue Liu

Research output: Contribution to journalArticlepeer-review

16 Scopus citations

Abstract

Gold was supported on commercial ZnO powders (P) and homemade ZnO nanowires (NWs) by a modified deposition-precipitation method. X-ray diffraction and transmission electron microscopy investigation indicated that the size of the Au nanoparticles (NPs) depended strongly on the calcination temperature. The Au NPs were highly dispersed (< 5 nm) on both supports with calcination temperatures < 400 °C. However, after calcination at 600 °C the Au NPs aggregated much more severely on ZnO P than on ZnO NWs. Gold NPs epitaxially grew into the {10-10} facets of the ZnO NWs after calcination at temperatures > 400 °C. Such unique anchoring mechanism accounts for the much better experimentally observed sintering resistance. X-ray photoelectron spectra showed that Au existed as both metallic Au0 and Auδ+ species in all the synthesized catalysts with or without calcination treatment; the ratios of Auδ+/Au0, however, varied, depending on the treatment conditions. Catalytic tests showed that the activity for CO oxidation strongly depended on the size of the Au NPs. After calcination at 600 °C, the specific rate for CO oxidation at room temperature decreased about 30 times on Au/ZnO P but only about 4 times on Au/ZnO NW. Stability tests demonstrated that the Au/ZnO NW catalysts had better stability for CO oxidation.

Original languageEnglish (US)
Pages (from-to)361-370
Number of pages10
JournalJournal of Energy Chemistry
Volume25
Issue number3
DOIs
StatePublished - May 1 2016

Keywords

  • CO oxidation
  • Epitaxy
  • Gold
  • Nanowires
  • Sintering
  • Stability
  • ZnO

ASJC Scopus subject areas

  • Fuel Technology
  • Energy Engineering and Power Technology
  • Energy (miscellaneous)
  • Electrochemistry

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