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 Ni2 catalyst (Ni2-NCNT) was controllably synthesized using a dinuclear Ni complex as the precursor, in which directly bonded Ni2 pairs are uniformly anchored on N-doped carbon nanotubes. Ni2-NCNT exhibits extraordinary catalytic activity, selectivity and stability for electroreduction of CO2 into CO, with a partial current density for CO (jCO) of 76 mA cm–2. The jCO mass activity of Ni2-NCNT is 2.3-times higher than that of corresponding Ni1-NCNT single-atom catalyst. DFT calculations reveal that the synergistic coordination of *COOH at the Ni2 dual-atom site can dramatically lower the reaction free energy for *COOH formation, thus promoting the CO2 electroreduction.