Low temperature lignin depolymerization to aromatic compounds with a redox couple catalyst

Development of selective lignin depolymerization method to valuable chemicals enhances the sustainability of downstream processing of biomass in a bio-refinery. The depolymerization of lignin is challenging due to its complicated structural pattern and changes during the process. Herein, we reported a low-temperature (~100 °C) oxidative depolymerization method for kraft lignin to aromatics by using a FeCl₃/NaNO₃/O₂ redox couple catalyst under mild conditions. The redox catalyst depolymerized the lignin with a limited quantity of catalyst. Experimental study reveals the formation of vanillic acid and vanillin as the major products during the process. This study explains a suitable method for valorization of lignin and as a whole effective method for depolymerization of lignin to aromatic which partially fulfill the future need of the Industry.