Selectivity in the gas-phase hydrogenation of 4-nitrobenzaldehyde over supported Au catalysts

Noemie Perret, Xiaodong Wang, Thomas Onfroy, Christophe Calers, Mark A Keane

Research output: Contribution to journalArticle

24 Citations (Scopus)

Abstract

The effects of Au particle size and support properties have been examined in the gas-phase hydrogenation of 4-nitrobenzaldehyde over Au/ZrO2, Au/TiO2 and Au/Al2O3. Gold particle size was varied using deposition-precipitation and impregnation syntheses. The catalysts have been characterised in terms of BET area/pore volume, temperature-programmed reduction (TPR), XRD, H-2 chemisorption/TPD, TEM, XPS, and pyridine adsorption FOR measurements. Reaction exclusivity to 4-aminobenzaldehyde was achieved over Au/ZrO2 and Au/TiO2 where a decrease in Au particle size (mean from 7.0 to 4.7 nm) generated a higher turnover frequency. Pyridine adsorption coupled with FTIR analysis has revealed stronger Lewis acidity associated with Au/Al2O3, which contributes to C=O reduction via the formation of a benzoate intermediate. Selectivity to the alcohol is sensitive to Au size and reaction temperature with 100% 4-nitrobenzyl alcohol selectivity over Au/Al2O3 (mean Au size = 7.8 nm) at 423-443 K. Our results demonstrate the viability of controlling selective -NO2 and C=O reduction using oxide-supported Au catalysts. (C) 2013 Elsevier Inc. All rights reserved.

Original languageEnglish
Pages (from-to)333-342
Number of pages10
JournalJournal of Catalysis
Volume309
DOIs
Publication statusPublished - Jan 2014

Keywords

  • Supported Au catalysts
  • Selective hydrogenation
  • 4-Nitrobenzaldehyde
  • Lewis acidity
  • Au particle size effects
  • AROMATIC NITRO-COMPOUNDS
  • GOLD CATALYSTS
  • CHEMOSELECTIVE HYDROGENATION
  • ACTIVE-SITES
  • CROTONALDEHYDE HYDROGENATION
  • SUBSTITUTED NITROAROMATICS
  • UNSATURATED ALCOHOLS
  • CARBONYL-COMPOUNDS
  • AU/ZRO2 CATALYSTS
  • REAL STRUCTURE

Cite this