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 CO2 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 CO2 electroreduction.