Mechanistic insights for dual-species evolution toward 5-hydroxymethylfurfural oxidation.

Electrochemical induced CuOOH/NiOOH active species performs the desirable activity for HMF oxidation. Nearly 100% FE (FDCA) was achieved in the paired-electrocatalytic system. Therefore, this work provides a new perspective for in-depth dissection of the reconstructed species. [Display omitted] • In-situ electrochemical reconstitution was proposed for CuO/Ni-BTC MOF. • Catalytic sites for HMF oxidation were determined as CuOOH/NiOOH species. • Close 100 % HMF conversion and 91.0 % FE FDCA were obtained at 0.55 V vs Ag/AgCl. • Paired electrocatalytic system exhibits superior performance for HMF oxidation. The biomass-derived 5-hydroxymethylfurfural (HMF) oxidation holds great significance for the sustainable production of value-added chemicals. However, the construction of active species with efficient oxidative-activity of alcohol/aldehyde still faces a great challenge. In this work, the reconstruction of CuO/Ni MOF successfully implanted CuOOH/NiOOH and deeply clarified their catalytic mechanism for HMF oxidation. It is worth noting that CuOOH/NiOOH exhibited an excellent self-healing ability during HMF oxidation, further realizing the reproducibility and long-term stability of catalyst. Moreover, a two-chamber electrocatalytic system combining HMF oxidation with 4-nitrophenol hydrogenation was established based on the activated CuO/Ni MOF. As a result, the overall reaction achieved a current density of 47.6 mA/cm2 at 0.55 V vs Ag/AgCl (3.0 h), and the corresponding conversion rate and Faraday efficiency reached nearly 100 %. This study provides new insight into the electrocatalytic-reconstruction strategy to implant active species for alcohol/aldehyde oxidation. [ABSTRACT FROM AUTHOR]