Combining autoclave and LCWM reactor studies to shed light on the kinetics of glucose oxidation catalyzed by doped molybdenum-based heteropoly acids

Dorothea Voß; Sebastian Ponce; Stefanie Wesinger; Bastian J M Etzold; Jakob Albert

doi:10.1039/c9ra05544d

Combining autoclave and LCWM reactor studies to shed light on the kinetics of glucose oxidation catalyzed by doped molybdenum-based heteropoly acids

RSC Adv. 2019 Sep 17;9(50):29347-29356. doi: 10.1039/c9ra05544d. eCollection 2019 Sep 13.

Authors

Dorothea Voß¹, Sebastian Ponce², Stefanie Wesinger¹, Bastian J M Etzold², Jakob Albert¹

Affiliations

¹ Lehrstuhl für Chemische Reaktionstechnik, Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 3 91058 Erlangen Germany jakob.albert@fau.de.
² Lehrstuhl für Technische Chemie, Technische Universität Darmstadt Alarich-Weiss-Straße 8 64287 Darmstadt Germany.

Abstract

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^-1 for the classical HPA-Mo to 61 kJ mol^-1 for the Ta- and 55 kJ mol^-1 for the Nb-doped species, respectively. Regarding catalyst reoxidation kinetics, the doping did not show significant differences between the different catalysts.