Efficient Conversion of Fructose Into 5‐HMF Over Zr‐O‐W Catalysts: Role of WO x Sub‐ and Nanoclusters

This work is dedicated to the development of new performing Zr‐O‐W‐mixed oxide catalysts for the direct conversion of fructose to 5‐hydroxymethylfurfural (5‐HMF) under soft operational conditions. By using sol–gel method, nanoclusters of WO x as active phase could be formed on the surface of the catalyst at low W loading (i.e., atomic ratio of W/Zr = 1/9), as revealed by different physico‐chemical characterizations (scanning transmission electron microscope with a high‐angle annular dark field [STEM‐HAADF], X‐ray diffraction [XRD], X‐ray photoelectron spectroscopy [XPS], etc.). The prepared catalysts show very good catalytic performance in the direct conversion of fructose into 5‐HMF under soft reaction conditions with the highest HMF yield of 95.8% (reaction conditions: 10 g/L catalyst loading, 120°C, 2 h of reaction, 5 wt.% of fructose in dimethyl sulfoxide [DMSO] solvent).