Performance of Preformed Au/Cu Nanoclusters Deposited on MgO Powders in the Catalytic Reduction of 4-Nitrophenol in Solution

Research output: Contribution to journalArticlepeer-review

Authors

  • Peter R. Ellis
  • Jian Liu
  • Christopher M. Brown
  • Guojing Chang
  • Dongjiang Yang
  • Jun Ren
  • Kevin Cooke
  • Peter T. Bishop

External organisations

  • Nanoscale Physics Research Laboratory, School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, UK
  • College of Engineering, Swansea University Bay Campus Fabian Way Swansea SA1 8EN
  • Johnson Matthey; Blount's Court, Sonning Common Reading RG4 9NH UK
  • Teer Coatings Ltd., Miba Coating Group, West Stone House, West Stone, Berry Hill Industrial Estate, Droitwich, Worcestershire, WR9 9AS
  • School of Chemical and Environmental Engineering; North University of China; Taiyuan 030051 P. R. China

Abstract

The deposition of preformed nanocluster beams onto suitable supports represents a new paradigm for the precise preparation of heterogeneous catalysts. The performance of the new materials must be validated in model catalytic reactions. It is shown that gold/copper (Au/Cu) nanoalloy clusters (nanoparticles) of variable composition, created by sputtering and gas phase condensation before deposition onto magnesium oxide powders, are highly active for the catalytic reduction of 4‐nitrophenol in solution at room temperature. Au/Cu bimetallic clusters offer decreased catalyst cost compared with pure Au and the prospect of beneficial synergistic effects. Energy‐dispersive X‐ray spectroscopy coupled with aberration‐corrected scanning transmission electron microscopy imaging confirms that the Au/Cu bimetallic clusters have an alloy structure with Au and Cu atoms randomly located. Reaction rate analysis shows that catalysts with approximately equal amounts of Au and Cu are much more active than Au‐rich or Cu‐rich clusters. Thus, the interplay between the Au and Cu atoms at the cluster surface appears to enhance the catalytic activity substantially, consistent with model density functional theory calculations of molecular binding energies. Moreover, the physically deposited clusters with Au/Cu ratio close to 1 show a 25‐fold higher activity than an Au/Cu reference sample made by chemical impregnation.

Details

Original languageEnglish
Article number1703734
JournalSmall
Volume14
Issue number13
Early online date7 Feb 2018
Publication statusPublished - 27 Mar 2018