Facile preparation of 2D nanomaterials by chelating agent-assisted electrodeposition for efficient electrochemical oxidation of biomass-derived aldehydes coupled with CO2 reduction

In this work, a novel paired electrolysis system was developed for efficient oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) and reduction of CO2 to formate. Particularly, by using chelating agent-assisted electrodeposition, 2D nano-structured electrocatalysts can be easily prepared with the morphology and catalytic performance being conveniently controlled by changing the type and dosage of chelating agents. EDTA2Na was found to be the most efficient to prepare Ni-based anode catalysts and Bi-based cathode catalysts. 98.7 % average FDCA yield and 93.9 % Faradaic efficiency (FE) were obtained with FDCA concentration reaching 159.1 g/L. The cathode catalyst (Bi-EDTA2Na) showed good performance for CO2 reduction to produce formate with FE of higher than 90 % in a potential range from -1.4 to -1.8 V vs. Ag/AgCl. By using a paired electrolysis system, 50.7 g/L FDCA and 10.8 g/L formate were obtained, with both FDCA yield and cathode FE being higher than 90 %.