Catalytic conversion of renewables: Kinetic and mechanistic aspects of the gold-catalyzed liquid-phase glucose oxidation
Pruesse, Ulf; Heidinger, S; Baatz, C
| HERO ID | 4382411 |
|---|---|
| In Press | No |
| Year | 2011 |
| Title | Catalytic conversion of renewables: Kinetic and mechanistic aspects of the gold-catalyzed liquid-phase glucose oxidation |
| Authors | Pruesse, Ulf; Heidinger, S; Baatz, C |
| Journal | Landbauforschung Voelkenrode |
| Volume | 61 |
| Issue | 3 |
| Page Numbers | 261-271 |
| Abstract | Among the studies about conversion of renewable resources, glucose oxidation to gluconic acid received very much attention in recent years. The present paper describes kinetic and mechanistic aspects of the liquid-phase glucose oxidation. Therefore a 0.3 % Au/Al2O3 catalyst prepared by the incipient wetness method was used. The reaction conditions were varied between 20 to 60 degrees C, pH 7 to 10, catalyst concentrations between 50 to 1200 mg l(-1) and initial glucose concentrations between 10 to 1000 mmol l(-1) The concentration of dissolved oxygen was tracked for most experiments. An increasing activity was found with increasing pH value in the range between pH 7 and 10, and with increasing temperature in the range between 20 and 60 degrees C, whereas the selectivity to gluconic acid remained unchanged at > 99 % under these conditions. The activation energy was determined to be 53 kJ mol(-1). Analysis of the reaction orders with regard to glucose and oxygen leads to the conclusion that the Eley-Rideal model proposed by Beltrame et al. (2006) should be discarded for the gold-catalyzed glucose oxidation. Hydrogen peroxide is formed as by-product in glucose oxidation under oxygen atmosphere, whereas hydrogenated products are by-products under oxygen-free conditions. These observations have been explained by a modified oxidative dehydrogenation mechanism. |
| Wosid | WOS:000297439200010 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |
| Keyword | conversion of renewables; gold catalyst; glucose oxidation; kinetics; mechanism |