Oxidative delignification is the chemical removal or structural breakdown of lignin from lignocellulosic material through oxidation of its aromatic and side-chain functional groups. The process involves an oxidizing species—such as molecular oxygen, hydrogen peroxide, ozone, chlorine dioxide, or an oxidatively active catalyst—that modifies lignin by introducing oxygen-containing groups, cleaving interunit linkages, fragmenting the macromolecular structure, and promoting dissolution or separation from the carbohydrate matrix ^[1][2][3]. Its defining objective is the preferential transformation and removal of lignin while retaining cellulose and, where relevant, a substantial fraction of hemicellulose. Oxidative delignification is therefore distinct from nonoxidative delignification, which relies primarily on hydrolytic, nucleophilic, or reductive reactions, and from bleaching in the narrower sense, which may chiefly remove chromophoric groups without causing extensive lignin solubilization. The term encompasses both oxidative pretreatment of lignocellulosic biomass and oxidative stages used in pulp processing, provided that lignin oxidation is central to the process ^[1][2][3].