An Empowered Spinel Electrocatalyst by Active [Cu ²⁺ Td –O–Co δ+ Oh ] Electron‐Shuttle Chain for Lignin Biomass Electrooxidation

Electrocatalytic lignin valorization enables the transformation of this renewable resource into high‐value‐added aromatic chemicals. Nevertheless, engineering catalysts capable of modulating the reaction surface‐lignin interaction, particularly in the context of the momentous C β –O–4 moiety, remains challenging. In this study, catalytic activity of the spinel Co 3 O 4 catalyst was enhanced by first identifying the active sites and then replacing the inert sites with Cu. The interfacial interaction was optimized by as‐constructed [Cu 2+ Td –O–Co δ+ Oh ] electron‐shuttle chain empowered electrocatalytic surface. Combined experimental and theoretical analysis revealed that the electronic chain structure increased the oxidation state of the active Co 3+ Oh site, thus effectively reshaping the adsorption configuration of the lignin. Compared with pristine Co 3 O 4 , the d‐band center shift contributed to a decrease in the energy barrier of the C β –H scission during substrate conversion, from 2.36 to 0.89 eV. Owing to the electron‐shuttle chain [Cu 2+ Td –O–Co δ+ Oh ], a maximum aromatic monomer yield of 81.92% was achieved with nearly complete conversion of lignin model compounds through electrocatalytic oxidative bond cleavage. Under the designed electrocatalyst, the depolymerization of native poplar lignin achieved a total monomer yield of approximately 16.25 wt.%.