Modulating the Electronic Structures of Dual-Atom Catalysts via Coordination Environment Engineering for Boosting CO2 Electroreduction.

ABSTRACT

Dual-atom catalysts (DACs) have emerged as efficient electrocatalysts for CO2 reduction owing to the synergistic effect between the binary metal sites. However, rationally modulating the electronic structure of DACs to optimize the catalytic performance remains a great challenge. Herein, we report the electronic structure modulation of three Ni2 DACs (namely, Ni2 -N7 , Ni2 -N5 C2 and Ni2 -N3 C4 ) by the regulation of the coordination environments around the dual-atom Ni2 centres. As a result, Ni2 -N3 C4 exhibits significantly improved electrocatalytic activity for CO2 reduction, not only better than the corresponding single-atom Ni catalyst (Ni-N2 C2 ), but also higher than Ni2 -N7 and Ni2 -N5 C2 DACs. Density functional theory (DFT) calculations revealed that the high electrocatalytic activity of Ni2 -N3 C4 for CO2 reduction could be attributed to the electronic structure modulation to the Ni centre and the resulted proper binding energies to COOH* and CO* intermediates.