Samarium-doped cobalt metal–organic framework as a versatile catalyst for the conversion of furfural and 2-methylfuran to high-value-added biofuel precursors

Abstract

The development of versatile catalysts for the conversion of biomass to value-added products is in great demand to tackle the environmental issues and depletion of fossil fuels required for energy. This work deals with the fabrication of a samarium-doped cobalt metal–organic framework (Sm/Co-TTA MOF) that provides acidic sites for catalysing the conversion of furfural and 2-methylfuran to a biofuel precursor 5,5′-(furan-2-ylmethylene)bis(2-methylfuran) (FMBMF) via hydroxyalkylation–alkylation (HAA). The Sm/Co-TTA MOF was obtained by a solvothermal process followed by doping with Sm³⁺ ions, and the material was characterized using FTIR spectroscopy, TGA, BET, FE-SEM, HR-TEM, PXRD, ICP-MS, TPD, and XPS analyses. The HAA reaction was carried out in water at 50 °C, obtaining 5,5′-(furan-2-ylmethylene)bis(2-methylfuran) in 89% yield in just 3 h. The product formation was verified using NMR spectroscopy and gas chromatography (GC-FID). The catalyst demonstrated excellent selectivity, efficiency, and stability, affording the desired products in high yields. These results have a high scope for promoting further biofuel research and development toward utilizing sustainable energy sources.