Non-noble Ni@NbOx Catalyst for Selective Hydrodehydroxylation of 5-Hydroxymethylfurfural to 5-Methylfurfural

Selective hydrogenation of substrates containing multiple unsaturated bonds (C & boxH;C and C & boxH;O) is a crucial catalytic process in the production of high-value chemicals. The development of nonprecious metal catalytic systems is of importance for hydrogenation processes due to the high cost and scarcity of noble metals. In this study, we have developed a straightforward and versatile encapsulation technique for the synthesis of Ni@NbOx catalysts, which enables highly selective hydrodehydroxylation of 5-hydroxymethylfurfural (HMF) to 5-methylfurfural (MF) under H-2. Mechanistic studies revealed that metallic Ni-0 encapsulated within NbOx facilitates hydrogen dissociation through an energy quasi-barrierless process (<0.1 eV), while simultaneously avoiding the adsorption of furan or C & boxH;O groups over Ni nanoparticles, therefore enhancing the selective hydrodehydroxylation of HMF to MF. Furthermore, the Ni@NbOx catalyst was tolerant to different conditions for selective hydrogenation, such as crude H-2 containing CO, substrates contaminated with various metal salts, etc.