Controlled synthesis of a Ni2 dual-atom catalyst for synergistic CO2 electroreduction

Dual-atom catalysts (DACs) have drawn much attention recently by virtue of the synergistic effect within the dual-atom sites, while controlled synthesis of pure DACs remains a challenge. Herein, a uniform dual-atom Ni 2 catalyst (Ni 2 -NCNT) was controllably synthesized using a dinuclear Ni complex as the precursor, in which directly bonded Ni 2 pairs are uniformly anchored on N-doped carbon nanotubes. Ni 2 -NCNT exhibits extraordinary catalytic activity, selectivity and stability for electroreduction of CO 2 into CO, with a partial current density for CO ( j CO ) of 76 mA cm –2 . The j CO mass activity of Ni 2 -NCNT is 2.3-times higher than that of corresponding Ni 1 -NCNT single-atom catalyst. DFT calculations reveal that the synergistic coordination of *COOH at the Ni 2 dual-atom site can dramatically lower the reaction free energy for *COOH formation, thus promoting the CO 2 electroreduction. An atomically precise dual-atom Ni 2 electrocatalyst was controllably synthesized using a dinuclear Ni complex as a precursor, which exhibits much higher electrocatalytic activity for CO 2 reduction to CO than the corresponding Ni 1 single-atom catalyst due to the synergistic effect at Ni 2 dual-atom catalytic site. • A strategy for controlled synthesis of pure dual-atom and single-atom catalysts was reported simply by modulating the ligands of the precursors. • The conditions for controlled synthesis of dual-atom catalyst were investigated in detail. • The j CO mass activity of dual-atom catalyst is 2.3-times higher than that of corresponding single-atom catalyst for CO 2 eledctroreduction due to the synergistic catalysis at Ni 2 dual-atom site.