Voß Dorothea, Ponce Sebastian, Wesinger Stefanie, Etzold Bastian J M, Albert Jakob
Lehrstuhl für Chemische Reaktionstechnik, Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 3 91058 Erlangen Germany
Lehrstuhl für Technische Chemie, Technische Universität Darmstadt Alarich-Weiss-Straße 8 64287 Darmstadt Germany.
RSC Adv. 2019 Sep 17;9(50):29347-29356. doi: 10.1039/c9ra05544d. eCollection 2019 Sep 13.
In this work we combined kinetic studies for aqueous-phase glucose oxidation in a high-pressure autoclave setup with catalyst reoxidation studies in a liquid-core waveguide membrane reactor. Hereby, we investigated the influence of Nb- and Ta-doping on Mo-based Keggin-polyoxometalates for both reaction steps independently. Most importantly, we could demonstrate a significant increase of glucose oxidation kinetics by Ta- and especially Nb-doping by factors of 1.1 and 1.5 compared to the classical HPA-Mo. Moreover, activation energies for the substrate oxidation step could be significantly reduced from around 80 kJ mol for the classical HPA-Mo to 61 kJ mol for the Ta- and 55 kJ mol for the Nb-doped species, respectively. Regarding catalyst reoxidation kinetics, the doping did not show significant differences between the different catalysts.
在这项工作中，我们将在高压釜装置中进行的水相葡萄糖氧化动力学研究与在液芯波导膜反应器中进行的催化剂再氧化研究相结合。据此，我们分别研究了铌和钽掺杂对钼基Keggin型多金属氧酸盐在两个反应步骤中的影响。最重要的是，我们可以证明，与传统的HPA-Mo相比，钽掺杂尤其是铌掺杂使葡萄糖氧化动力学显著提高，分别提高了1.1倍和1.5倍。此外，底物氧化步骤的活化能可从传统HPA-Mo的约80 kJ/mol显著降低至钽掺杂物种的61 kJ/mol和铌掺杂物种的55 kJ/mol。关于催化剂再氧化动力学，掺杂在不同催化剂之间未显示出显著差异。
