Promoted selectivity in lignin C_αC_β bonds cleavage by anodic oxidation with coupled reactive oxygen species through a...

Lignin is the primary renewable source of aromatic compounds in nature, and efficiently valorizing lignin can potentially help address the conflict between energy resources supply and demand. Electrochemical oxidation, when combined with extra oxidizing mediums, would be considered as a more powerful and environmentally friendly tool for lignin depolymerization. However, possible mechanisms of these combined oxidation processes lack to be fully elucidated. Herein, reactive oxygen species (ROSs) have been introduced into electrochemical conversion processes of both βO4 model compounds and organosolv birch lignin through a coupled O₂ cathodic reduction to better improve the efficiency of power utilization. Supported by electrochemical, in situ spectroelectrochemical and product analysis studies, a combined oxidation path has been revealed for the conversion processes of dimers with contributions of anode and O₂ cathodic reduction induced ROSs. In particular, this study also addresses the role of ROSs in the promoted selectivity of C_αC_β bond cleavage and further clarified the dimer structural and electrochemical process effects on product distribution for lignin conversion in details as well.