iScience. 2022 Jul 9;25(8):104744. doi: 10.1016/j.isci.2022.104744. eCollection 2022 Aug 19.
Electrochemical 5-hydroxymethylfurfural oxidation reaction (HMFOR), as a clean biorefinery process, promotes a circular economy with value-added products. In HMFOR, the intrinsic catalytic activity and charge transfer mechanisms are crucial. Herein, nickel, co-deposited with phosphorus (Ni-P), attains superior electrocatalytic performance compared with Ni and its oxyhydroxides for the HMFOR. Such electrocatalytic activity of the Ni-P catalyst is attributed to the high oxidation state of surface Ni species, supported by the bulk Ni-P component. An unprecedented charge storing capacity enabled by the bulk Ni-P material maintains the spontaneous reaction between HMF and Ni3+ species to achieve a current density of 10 mA/cm2 normalized by the electrochemical active surface area at a low potential of 1.42 V vs RHE, reaching a 97% Faradaic efficiency toward 2,5-furandicarboxylic acid. This work, for the first time, sheds light on the importance of the electrode bulk material by showcasing the HMFOR via the Ni-P catalyst incorporating a charge-holding bulk component.