Asymmetric Cu-N-La Species Enabling Atomic-Level Donor-Acceptor Structure and Favored Reaction Thermodynamics for Selective CO 2 Photoreduction to CH 4 .

Photocatalytic CO 2 reduction into ideal hydrocarbon fuels, such as CH 4 , is a sluggish kinetic process involving adsorption of multiple intermediates and multi-electron steps. Achieving high CH 4 activity and selectivity therefore remains a great challenge, which largely depends on the efficiency of photogenerated charge separation and transfer as well as the intermediate energy levels in CO 2 reduction. Herein, we construct La and Cu dual-atom anchored carbon nitride (LaCu/CN), with La-N 4 and Cu-N 3 coordination bonds connected by Cu-N-La bridges. The asymmetric Cu-N-La species enables the establishment of an atomic-level donor-acceptor structure, which allows the migration of electrons from La atoms to the reactive Cu atom sites. Simultaneously, intermediates during CO 2 reduction on LaCu/CN demonstrate thermodynamically more favorable process for CH 4 formation based on theoretical calculations. Eventually, LaCu/CN exhibits a high selectivity (91.6 %) for CH 4 formation with a yield of 125.8 μmol g -1 , over ten times of that for pristine CN. This work presents a strategy for designing multi-functional dual-atom based photocatalysts.