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.