Doped Mn Enhanced NiS Electrooxidation Performance of HMF into FDCA at Industrial‐Level Current Density

Abstract Electrooxidation of 5‐hydroxymethylfurfural (HMF) into 2,5‐furandicarboxylic acid (FDCA) is a highly promising approach for producing value‐added chemicals from biomass. However, developing highly efficient electrocatalysts for HMF oxidation (HMFOR) with high current density in large‐scale productions remains a challenge. Herein, it is demonstrated that the Mn‐doped NiS nanosheet electrocatalysts grown directly on 3D graphite felt (GF) substrates can efficiently perform electrooxidation of HMF into FDCA at industrial‐level current density (500 mA cm −2 ) in the H‐cell. The Mn 0.2 NiS/GF exhibits excellent HMFOR performance with high selectivity (98.3%), yield (97.6%), faradaic efficiency (94.2%), and robust stability (10 cycles). Especially, FDCA production rate up to 4.56 g h −1 can be achieved, superior to those reported in HMFOR literatures. Furthermore, by scaling up the Mn 0.2 NiS/GF electrode area and assembling it in a continuous‐flow electrolyzer, high FDCA production rate of 44.32 g h −1 is achieved. The high activity of Mn 0.2 NiS/GF for HMFOR can be attributed to incorporation of Mn into NiS material, theoretical calculation results indicate that the Mn and Ni as both the adsorption sites for HMF oxidation, thereby effectively facilitate the HMF electro‐oxidation performance. This work provides a strategy for developing potential industrial‐grade electrocatalysts at a large current density.