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 CoOx/Nb2O5 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 Nb2O5 and CoO via the Nb-O-Co bond in CoOx/Nb2O5-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 Co3O4 and Nb2O5 assisted the adsorption of FF. Further, DFT calculations verified CoO was the main adsorption site for FF adsorption in CoOx/Nb2O5-ctr. Moreover, CoOx/Nb2O5-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.

Automated summary

In this study, a CoOx/Nb2O5 nanostructure catalyst was synthesized for the selective hydrogenation of furfural (FF) to furfuryl alcohol (FA). The optimized conditions resulted in a 95.7% yield of FA with a TOF of 155.7 h-1. The catalyst characterization revealed the interaction between Nb2O5 and CoO, which prevented the further reduction of CoO to metal Co. DFT calculations confirmed that CoO was the main adsorption site for FF in CoOx/Nb2O5-ctr.