Electrocatalytic Cleavage of C–C Bonds in Lignin Models Using Nonmetallic Catalysts at Ambient Conditions

Abstract

Lignin, characterized by its amorphous, heavily polymerized structure, is a primary natural source of aromatic compounds, yet its complex constitution poses considerable challenges in its transformation and utilization. Therefore, the selective cleavage of C−C bonds represents a critical and challenging step in lignin degradation, essential for the production of high-value aromatic compounds. In this study, we report a simple electrocatalytic approach for lignin valorization via C−C bond cleavage by developing a nonmetallic electrocatalyst of carbon-based materials. It is found that the hydrophilicity and hydrophobicity of the electrocatalyst have a significant effect on the degradation process. Under mild conditions, the hydrophilic carbon paper exhibits 100% substrate conversion, yielding 97% benzaldehyde and 96% quinone with ionic liquid electrolytes. The mechanism study shows that the carbon catalyst with higher surface defects favors electron transfer in the oxidative cleavage process of C−C bonds. These results signify a substantial advancement in lignin degradation, offering an environmentally friendly, metal-free electrochemical route.