Acetic acid production by selective oxidation of ethanol using Au catalysts supported on various metal oxide

• Published in: Gold Bulletin 2009-01, Vol.42 (4), p.321-327
• Main Authors: Tembe, Steton M., Patrick, Gary, Scurrell, Mike S.
• Format: Article
• Language: English
• Subjects: Chemistry and Materials Science; Materials Science; Metallic Materials
• ISSN: 0017-1557; 2190-7579
• DOI: 10.1007/BF03214954

The liquid-phase oxidation of ethanol to acetic acid using Au catalysts supported on various metal oxides was studied at 150°C using molecular oxygen as stoichiometric oxidant. Catalysts containing 1 wt% Au supported on TiO 2 , Al 2 O 3 , and ZnO were examined for ethanol oxidation. The results showed that ZnO and TiO 2 gave higher initial activities as supports for gold in ethanol oxidation, followed by Al 2 O 3 . Ethanol conversions of >90% and selectivities to acetic acid of >95% were achieved when using ZnO and TiO 2 as supports under conditions where a slight oxygen deficiency was used. With a slight excess of oxygen present initially, ethanol conversions of 99.4%, and a selectivity to acetic acid selectivity of 99.8% could be achieved. Gold leaching seemed to be very apparent with alumina as support and also, after continued use with titania-based catalysts. The use of higher initial concentrations of ethanol (range studied 5–40 mass% ethanol in water) led to higher ethyl acetate selectivities. High acetic acid selectivities were seen for relatively low (5–10 mass%) initial ethanol concentrations.