Highly selective production of the biofuel 2,5-dimethylfuran from 5-hydroxymethylfurfural over Co/N–C catalysts

Abstract

A simple and efficient method for the catalytic synthesis of 2,5-dimethylfuran (DMF) from 5-hydroxymethylfurfural (HMF) was investigated, and Co/N–C catalysts with different cobalt contents, which demonstrated high catalytic activity for the selective hydrogenation of HMF to DMF, were prepared by a solvothermal crystallization method. The catalysts were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric and derivative thermogravimetric analyses, and N₂ adsorption–desorption analysis. The effects of cobalt loading rate, calcination conditions, and reaction conditions were investigated. At relatively low reaction temperatures and hydrogen pressures, 99.9% conversion of HMF and 98.5% selectivity for DMF were achieved using the Co_0.25/N–C-500 catalyst. This excellent catalytic activity was attributed to the high dispersion of Co nanoparticles in the porous structure of the N–C backbone, which resulted in the formation of Co–N_x species. The catalyst exhibited good recyclability and recoverability in a six-run recycling test.