Oxidized Lignin Depolymerization using Formate Ionic Liquid as Catalyst and Solvent

Abstract Lignin has been widely studied as a sustainable source of renewable materials, particularly aromatic feedstock chemicals, which are in great and increasing need in the world. Lignin oxidation and depolymerization presents a promising approach to functionalized phenolic products. In this work, a novel oxidative degradation of lignin using a formate ionic liquid was investigated resulting in ethyl acetate soluble and also water‐soluble depolymerized lignin products. The β‐ O ‐4 bonds in lignin were oxidized and then depolymerized by a recyclable ionic liquid, 2‐hydroxy ethylammonium formate. 2‐Hydroxy ethylammonium formate, which could dissolve lignin acting as a solvent, was found to also catalyze the depolymerization of the oxidized lignin. The lignin depolymerization products were characterized.