Gold-catalyzed selective glucose oxidation at high glucose concentrations and oxygen partial pressures

The aqueous-phase glucose oxidation was studied at initial glucose concentrations of 1-57.5 wt% and oxygen partial pressures of 1.5-9 bar using a 0.3% Au/Al2O3 catalyst. The highest activity at 40 degrees C (about 5200 mmol min(-1) g(Au)(-1)) was observed at an initial glucose concentration of 20 wt% and an oxygen pressure of 9 bar. The apparent activation energy was determined to 54 kJ mol(-1). Kinetic analysis revealed that the reaction is likely to follow the Langmuir-Hinshelwood model. The catalyst possessed a high long-term stability in ten repeated batches at 20 wt% initial glucose concentration. (C) 2011 Elsevier B.V. All rights reserved.