Atomic-level Rhodium Doping into NiO for Boosting the Selective Electrooxidation of HMF to FFCA in Neutral Electrolyte

The oxidation reaction of the biomass derivative 5-hydroxymethylfurfural (HMF) holds immense promise for the sustainable synthesis of high-value chemicals. Nevertheless, achieving the selective electrooxidation of HMF to generate high value-added formyl-2-furan carboxylic acid (FFCA) intermediate remains a serious challenge. Here, the V-NiO-Rh catalyst was constructed and demonstrates an impressive FFCA selectivity of 71 % for HMF electrooxidation reaction (HMFOR) in neutral electrolyte. The designed experiments elucidate that the HMFOR mechanism is the co-adsorption of OH* and HMF* on Ni active sites. Furthermore, the theoretical calculations prove that the modulation of Ni electronic structure by single atom Rh promotes the ability of HMF adsorption and the water electrolysis to release OH*. This paper establishes a theoretical foundation for the selective synthesis of high value-added intermediates products that are challenging to obtain in alkaline media.