Selective Electrocatalytic Production of Formic Acid from Plastic Waste Using a Nickel Metal–Organic Framework Constructed from a Biomass-Derived Ligand

Abstract

A novel nickel-based metal organic framework (MOF) [Ni(FDC)(CH3OH)1.5(H2O)0.5](H2O)0.35 (UOW-6) utilizing biomass-derived 2,5-furan dicarboxylate (FDC) as a ligand is reported as an electrocatalyst for anodic ethylene glycol (EG) oxidation with cathodic hydrogen evolution. The MOF structure was analyzed using single crystal X-ray-diffraction, thermogravimetric analysis (TGA) and thermodiffractometry, to establish its structure and verify phase purity. The material was dropcast on carbon fiber paper as a catalyst, and by using a three-electrode system, UOW-6 requires only 1.47 V to attain a current density of 50 mA cm−2. During oxidation of the EG, UOW-6 shows unprecedented selectivity towards formic acid with a Faradaic efficiency of 94 % and remarkable stability over 20 days. The combination of electrochemical measurements and in situ Raman confirmed in situ formed NiOOH at the surface of UOW-6 as the catalytically active sites for EG oxidation. This work not only presents a pioneering application of FDC-based MOFs for polyethylene terephthalate (PET) upcycling but also underscores the potential of electrocatalysis in advancing sustainable plastic valorization strategies.