W exsolution promotes the in situ reconstruction of a NiW electrode with rich active sites for the electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF)

The electrocatalytic HMF oxidation reaction (HMFOR) is one of the promising technologies for the valorization of biomass derivatives and potential replacements for the energy-consuming oxygen evolution reaction (OER). For the most investigated Ni-based electrode, the in situ reconstruction from Ni(OH)2 to NiOOH is hardly avoidable during the electro-oxidation reaction, which is also a highly indispensable prerequisite towards HMFOR. Herein, we developed an efficient strategy of sacrificing W to investigate the effect of surface defects on the self-reconstruction of Ni for promoting HMFOR. It was rationalized that the selective and rapid exsolution of the W species from the as-prepared NiW layer created a porous structure and induced lattice defects on the surface, which facilitated the ion and electron transportation, and further promoted the in situ reconstruction for the formation of higher oxidated Ni with superior activity for HMFOR. This work offers a novel and low-cost means to enrich the active sites for the electrocatalytic upgrading of HMF and other bio-derived platforms.