Design of high-performance g-C6N6-based dual-atom catalysts for CO2-to-CH4 conversion via first-principles screening

Electrochemical CO 2 reduction (CO 2 RR) is a promising strategy for carbon neutrality, yet it is hindered by CO 2 inertness and complex reaction pathways. Herein, 21 homonuclear and heteronuclear transition metal dual-atom catalysts (DACs) anchored on graphitic carbon nitride (g-C 6 N 6 ), denoted as TM1TM2@g-C 6 N 6 , are designed and studied via density functional theory (DFT) calculations. With CO 2 adsorption strength and differential binding energies of *CO/*CHO as descriptors, MnMn@g-C 6 N 6 and CrCu@g-C 6 N 6 are screened out with outstanding performance. Both catalysts show stable N-coordination, significant charge transfer, and synergistic activation of CO 2 . They selectively produce CH 4 with low free energy changes for the potential-determining steps (0.43 and 0.37 eV) and suppress the competing hydrogen evolution reaction (HER). This work offers theoretical guidance for developing advanced g-C 6 N 6 -based CO 2 RR catalysts.