Aerobic selective oxidation of glucose to gluconate catalyzed by Au/Al2O3 and Au/C: Impact of the mass-transfer processes on the overall kinetics
Delidovich, IV; Moroz, BL; Taran, OP; Gromov, NV; Pyrjaev, PA; Prosvirin, IP; Bukhtiyarov, VI; Parmon, VN
| HERO ID | 4339522 |
|---|---|
| In Press | No |
| Year | 2013 |
| Title | Aerobic selective oxidation of glucose to gluconate catalyzed by Au/Al2O3 and Au/C: Impact of the mass-transfer processes on the overall kinetics |
| Authors | Delidovich, IV; Moroz, BL; Taran, OP; Gromov, NV; Pyrjaev, PA; Prosvirin, IP; Bukhtiyarov, VI; Parmon, VN |
| Journal | Chemical Engineering Journal |
| Volume | 223 |
| Page Numbers | 921-931 |
| Abstract | Aerobic oxidation of glucose in the presence of Au/Al2O3 catalysts with different dispersion of supported gold and Au/C catalysts containing highly dispersed gold nanoparticles was studied at varied glucose:Au molar ratios. The studies were focused on determining the contribution of the mass-transfer processes to the overall reaction kinetics in different regimes. The Au/Al2O3 catalysts were more active than the Au/C catalysts at high glucose:Au molar ratios. Among the alumina-supported catalysts with different metal dispersion, the highest TOF at high glucose:Au molar ratios was characteristic of the Au/Al2O3 catalysts bearing metal particles of 1-5 nm in size. Under these conditions, the high effectiveness factor of the Au/Al2O3 catalysts (>95%) was observed at a uniform gold distribution through the support granules. For the Au/C catalysts with the non-uniform distribution of gold nanoparticles through the catalyst grains, the apparent reaction rate was affected by internal diffusion (the effectiveness factor of a catalyst grain is ca. 70%), while the interface gas liquid solid oxygen transfer influenced the overall reaction kinetics as well. At a low glucose:Au molar ratio the reaction rate was limited by oxygen dissolution in the aqueous phase. In this mass transfer regime the rate of glucose oxidation over the carbon-supported catalysts exceeds the reaction rate over the alumina-supported catalyst, which is attributed to a higher adhesion of the hydrophobic carbon support to the gas liquid interface facilitating the oxygen mass transfer towards catalytic sites. (C) 2012 Elsevier B.V. All rights reserved. |
| Doi | 10.1016/j.cej.2012.11.073 |
| Wosid | WOS:000320631200105 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |
| Keyword | Selective oxidation; Gold catalyst; Carbon; Alumina; Glucose; Gluconic acid; Mass transfer |