Breaking the activity-selectivity dilemma in direct electrocatalytic hydrogenolysis of furfural into furanic biofuel.

Abstract

Electrocatalytic hydrogenolysis of biomass-derived furfural usually encounters the disordered flow of electrons, particularly for the formation of 2-methylfuran with a complex four-electron transfer process. To address this, we develops an intermediates coverage-induced strategy through the mixed valences in copper clusters wrapped by carbonaceous matrix, which boosts the transfer of electrons toward 2-methylfuran with dual advantages in kinetics and thermodynamics. Experimental results indicate that the carbonaceous matrix create a furural-favorable environment for less adsorption of H⁺; on it surface, the cleavage of C-O bonds in Fur-CH₂OH^* can be easily activated by Cu⁺ sites for 2-methylfuran, while partial participation of Cu⁰ accelerates the hydrogenation processes with an enhancement of local H^* concentration, leading to the high selectivity and faradaic efficiency at 89.8% and 76.6%, respectively. In addition, the coexistence of Cu⁺ and Cu⁰ is also stable under cathodic conditions, but the deposition of polymers disturbs the intermediates coverage, which is subsequently mitigated through the continuous-flow reactor. This study provides insights into the interfacial modulation on electrode surface, advancing the development of efficient electrocatalysts for biomass valorization.