High-efficiency synthesis of 2,5-diformylfuran from 5-hydroxymethylfur-fural using iron-bismuth-molybdenum oxides

Herein we report the synthesis of various of iron-bismuth-molybdenum oxides (Fe3BiMo8-12O30-42) catalysts via a straightforward alkali-coprecipitation method. These catalyts exhibited notable highly efficiency as heterogeneous catalysts for the aerobic oxidation of HMF to DFF. Among the catalysts investigated, Fe3BiMo12O42 (pH = 1-2) exhibited exceptional efficiency, achieving high HMF conversion (98 %) with high selectivity (>99 %) and turnover numbers (TONs) up to 379, representing 1-2 orders of magnitude improvement than previously reported non-noble catalysis systems. The Fe3BiMo12O42 (pH = 1-2) catalyst demonstrated sustained high selectivity after five usage cycles, highlighting its practical recyclability and stability. Comprehensive characterization of the catalysts and control experiments provided insights into active sites along with the structural, morphological, and surface properties. Furthermore, a convenient one-pot, two-step process utilizing Fe3O4@SiO2-SO3H and Fe3BiMo12O42 in tandem successfully produced DFF from fructose with an impressive overall yield of 85%, showcasing potential for sustainable and eco-friendly biomass conversion.