MIL-47(v)-derived carbon-doped vanadium oxide for selective oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran

Abstract

The development and transformation of biomass-derived platform compounds is a sustainable way to deal with the fossil fuel crisis. 5-Hydroxymethylfurfural (HMF) can be reduced or oxidized to produce many high-value compounds; however, it is challenging to effectively produce 2,5-diformylfuran (DFF) due to overoxidation. In this work, a carbon-doped V₂O₅ (C–V₂O₅) material was obtained through pyrolysis of MIL-47(V) nanorods, a typical metal–organic framework material. The X-ray diffraction patterns and X-ray photoelectron spectra showed that the graphitized carbon species were incorporated in C–V₂O₅. High-efficiency HMF oxidation, high specific selectivity for DFF and excellent recycling could be achieved with the C–V₂O₅ catalyst. Fourier-transform infrared spectroscopy combined with density functional theory (DFT) calculation revealed that graphitized carbon weakens the VO bond and promotes the formation of oxygen vacancies in C–V₂O₅, thus improving the catalytic activity in the oxidation of furfuryl alcohols. The V⁴⁺ induced by oxygen vacancies will be oxidized by O₂ to form V⁵⁺, so that the cycle can be realized. It exhibits remarkable selectivity in the oxidation of different alcohols produced from biomass based on the relatively constant active sites in C–V₂O₅.