Selective oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran over niobium incorporated MCM-41 catalyst

Mesoporous supports with metal incorporation have emerged as productive heterogeneous catalysts with high conversion/selectivity in organic synthesis and biomass conversion. In the present work, niobium incorporated mesoporous materials (Nb-MCM-41) has been fabricated with different Si/Nb (33 and 64) ratios by hydrothermal method followed by calcination. The solid Nb-MCM-41 catalysts were characterized to study crystal structure, stability, porosity and acidity by X-Ray diffraction analysis (XRD), thermogravimetric analysis (TGA), N2 adsorption-desorption, and ammonia-temperature programmed desorption (NH3-TPD). The prepared catalysts were employed in the oxidation of model biomass intermediate 5-hydroxymethylfurfural (HMF). The Nb-MCM41 (64) solid catalyst was highly efficient with high HMF conversion and selectivity of 2,5-diformylfuran (DFF). The total acidity and prevailing oxidative active sites of niobium species over MCM-41 plays a vital catalytic role in the oxidation of HMF. Altogether, a versatile catalytic system has been proposed with higher life span on recyclability that can be regenerated after longer runs.

Automated summary

Mesoporous supports with metal incorporation have shown high catalytic activity in organic synthesis and biomass conversion. The niobium incorporated mesoporous materials (Nb-MCM-41) fabricated in this study exhibited efficient conversion of HMF with high selectivity to DFF. Characterization of the solid Nb-MCM-41 catalysts using X-Ray diffraction, thermogravimetric analysis, and other techniques revealed their crystal structure, stability, porosity, and acidity.