Liquid flow fuel cell with an electrodeposition-modified nickel foam anode for efficient oxidation of 5-hydroxymethylfurfural to produce 2, 5-furandicarboxylic acid with co-generation of electricity

Liquid flow fuel cells were developed as reactors for efficient conversion of 5-hydroxymethylfurfural (HMF) to 2, 5-furandicarboxylic acid (FDCA) at room temperature with co-generation of electricity. Electrodeposition modification of nickel foam (NF) with CoSO4 and NaH2PO2 (Co-P@NF anode) was found to significantly increase HMF oxidation efficiency, due to the reduction of polarization resistance of NF and increased electrochemical active area. However, the active species of Co-P@NF anode for HMF oxidation actually was NiOOH rather than cobalt. By using (VO2)2SO4 as a cathodic electron carrier, peak power density of 38.9 mW/cm2 at room temperature was obtained with 100% HMF conversion and 89.0–93.4% FDCA yield. FDCA concentration reached 81.8 g/L with 90% total yield after feeding HMF for six batches. Therefore, efficient production of FDCA was achieved under mild conditions with oxygen (air) as the final oxidant via the electron transport chains constructed by active nickel species and cathode electron carriers.