Rational Design of a Bifunctional Catalyst for the Oxydehydration of Glycerol: A Combined Theoretical and Experimental Study

Abstract

Due to its cost effectiveness and eco-friendliness, oxydehydration of glycerol is currently attracting considerable attention. In an attempt to develop an efficient catalyst for the reaction, tungsten-incorporated molybdenum vanadium mixed oxide (MoVW) catalysts were designed on the basis of computational calculations and mechanistic insights. By incorporating tungsten into molybdenum vanadium mixed oxide structure, the catalysts are active and selective not only for the dehydration of glycerol but also for the subsequent oxidation of acrolein to acrylic acid. Through DFT calculations, we confirmed that tungsten species induced a change in the electron density of neighboring atoms, which leads to selective production of acrylic acid. Structural characterization demonstrates that the structure of such MoVW catalysts is similar to that of DFT models. The incorporated tungsten species enhanced the add and redox properties of the catalyst, leading to high selectivity for acrylic acid (30.5%). It not only induced but also stabilized the reduced oxidation states of molybdenum and vanadium atoms, as confirmed by XPS and DFT calculations. Hence, a stable and selective production of acrylic add was achieved with full glycerol conversion for 110 h. The MoVW catalytic system with an additional acid catalyst bed exhibited remarkable selectivity for acrylic add (47.2%), suggesting its potential for practical applications.