Green and efficient selective hydrogenation of furfural to furfuryl alcohol over hybrid CoOx/Nb2O5 nanocatalyst in water

The selective hydrogenation of the C=O group in biomass-derivate furfural (FF) over noble metal-free catalysts is challenging in aqueous. Herein, a CoO x /Nb 2 O 5 nanostructure catalyst was synthesized for the hydrogenation of FF to furfuryl alcohol (FA). Under optimized conditions, a 95.7% yield of FA was obtained with a TOF of 155.7 h −1 , and the kinetic study revealed that the reaction followed a pseudo-first-order pathway with an activation energy of 39.42 kJ mol −1 . The catalyst characterization indicated the interaction between Nb 2 O 5 and CoO via the Nb-O-Co bond in CoO x /Nb 2 O 5 -ctr, which prevented the further reduction of CoO to metal Co in the catalyst's preparation process. The catalytic mechanism suggested CoO was the dominant hydrogenation/adsorption active, whilst Co 3 O 4 and Nb 2 O 5 assisted the adsorption of FF. Further, DFT calculations verified CoO was the main adsorption site for FF adsorption in CoO x /Nb 2 O 5 -ctr. Moreover, CoO x /Nb 2 O 5 -ctr showed outstanding recyclability for the selective hydrogenation of FF to FA ever after five runs. This work provides opportunities for the clean conversion of biomass-based FF to FA and infers potential applications of Co for the large-scale hydrogenation of bio-based platform chemicals.