Switching Products Selectivity in Electrocatalytic C(sp3)‐H Bonds Activation and CO2 Carboxylation via Cu‐S Bond Crystal Engineering

Inert C(sp3)‐H bonds activation along with CO2 carboxylation to prepare high‐value carboxylic acids is a sustainable route for achieving the carbon‐neutral goal, but the current catalytic performance is far from satisfying the demand. Targeting this problem, it was found that crystal engineering of Cu‐S bonds not only significantly enhanced the activity of C(sp3)‐H activation and CO2 carboxylation in an electrocatalytic system, but also efficiently realized chemoselectivity in the CO2 carboxylation process. Specifically, hexagonal CuS(001) electrocatalyst could readily achieve C(sp3)‐H bond activation of alkanes and aromatics along with CO2 carboxylation, exhibiting almost complete chemoselectivity to carbon chain increased monocarboxylation acids. Intriguingly, hexagonal Cu2S(110) electrocatalyst, which was prepared by phase transition, could realize highly selective alkanes and aromatics dicarboxylation with CO2 to produce dicarboxylation acids. Notably, biomass compound 2‐methylfuran was efficiently converted into furan‐2‐acetic acid over CuS(001); while 2,5‐dimethylfuran was quantitatively converted to the degradable polymer precursor furan‐2,5‐dicarboxylic acid over Cu2S(110). Moreover, density functional theory (DFT) results revealed the origin of differences in the activity and chemoselectivity over CuS(001) and Cu2S(110) catalysts.