Insight into the noble-metal-free NiCoAl catalyst boosting the reductive esterification of furancarboxylic acid to methyl 2-tetrahydrofuroate

Reduction of high oxidation level furancarboxylic acid (FA) with the retention of the carboxyl group is particularly important for the utilization, however, it has been rarely explored over non-precious catalysts and is challenging. Here, we demonstrate an excellent noble-metal-free trimetallic NiCoAl catalyst for the reductive esterification of FA to methyl 2-tetrahydrofuroate (MeTHFC), which delivers the complete conversion of FA and MeTHFC yield of up to 99%. More importantly, Ni 0.5 Co 0.5 Al could offer Y MeTHFC  > 90% over five reusability cycles. Detailed investigations suggest that the high activity originates from the synergistic of Ni-Co alloys sites and acid sites in Ni 0.5 Co 0.5 Al. The Ni-Co alloy sites were mainly responsible for the adsorption and dissociation of H 2 , which in turn improved hydrogenation activity, while the acid sites facilitated the esterification of FA and the adsorption and further activation of the furan ring. This work provides an eco-friendly noble-metal-free catalyst to enrich the strategies for the reductive esterification process.