Enhancing Ni oxidation reconstruction in Ni3Fe nanoalloy for efficient Electro-Oxidation of 5-Hydroxymethylfurfural

Herein, a novel ball milling-pyrolysis strategy was proposed for preparing a highly dispersed Ni₃Fe nanoalloy catalyst (Ni₃Fe@NC) used for 5-hydroxymethylfurfural (HMF) electro-oxidation reaction. The Ni₃Fe@NC delivered a high current density of 100 mA cm⁻² at a low potential of 1.467 V vs RHE, with a HMF conversion rate of over 99.6 %, 2,5-furan dicarboxylic acid (FDCA) selectivity of 97.1 % and a Faraday efficiency of 96.7 %. Theoretical calculations, in-situ EIS, quasi-in-situ XRD and XPS demonstrated that Fe-doping optimizes the electronic structure of Ni₃Fe@NC and regulates its d-band center, which not only promoted the reconstruction of Ni₃Fe@NC to form high-oxidation-activity Ni^2+δ and Ni^3+δ species but also reduced the reaction barrier of the key rate-determining step (*5-Hydroxymethyl-2-furancarboxylic acid (HMFCA)→*5-formyl-2-furancarboxylic acid (FFCA)) during HMFOR. Based on this interesting work, we provided a facile macroscopic preparation strategy on highly dispersed nanoalloy catalyst for efficient electro-oxidation of HMF.