Selective hydrogenolysis of biomass-derived 5-hydroxymethylfurfural to 2,5-dimethylfuran over a unique Co@CN catalyst

Developing precious-metal-free catalysts for the selective hydrodeoxygenation of biomass-derived 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF) is critical yet challenging. Herein, a series of non-noble metal Co@CN-T catalysts were designed and fabricated, which can efficiently catalyze the selective hydrogenolysis of HMF to DMF under mild reaction conditions of 140 °C, with the selectivity of the target product reaching as high as 99%. The Co-N x coordination active sites serve as Lewis acid sites, which can preferentially activate the C=O bond in HMF. Such selective activation promotes the effective hydrogenolysis of the intermediate 2,5-bis(hydroxymethyl)furan (BHMF) to 5-methylfurfuryl alcohol (MFA), reduces intermediate accumulation, and thus guarantees high selectivity toward DMF. In addition, the Co@CN-T catalysts also exhibited excellent stability, and their catalytic activity remained stable without obvious attenuation after five consecutive cycles of reaction. This study offers theoretical insights into the use of non-noble metal catalysts for the hydrodeoxygenation of renewable biomass to produce chemical feedstocks.