Mediating heterogenized nickel phthalocyanine into isolated Ni-N3 moiety for improving activity and stability of electrocatalytic CO2 reduction

The poor stability of heterogenized nickel phthalocyanine (NiPc) has hindered its application as a desirable catalyst for electrocatalytic carbon dioxide reduction. Herein, the electrocatalytic stability of heterogenized NiPc on nitrogen-doped hollow carbon nanospheres (NiPc@NHCSs) can be optimized via mediating NiPc into Ni-NC moiety (Ni-NC/NHCSs-Y) to construct a stable Ni catalytic unit. Different from the poor activity of NiPc@NHCSs (CO Faradaic efficiency, FECO< 80%, stability < 1200 s), the optimal catalyst (Ni-NC/NHCSs-600) with unsaturated Ni-N3 nitrogen-vacancy structure, displays FECO of 98.57% and CO turnover frequency of 3.75 s−1 at − 0.87 V vs. RHE, and stable operation over 14 h (−0.82 V vs. RHE). The stabilization mechanism and the temperature effect on the structure-activity relationship are systematically explored, which successfully steers the design of stable Ni-NC catalytic unit on different carbon substrate, while a zinc-CO2 rechargeable battery is constructed, displaying a peak power density of 0.64 mW cm−2 and FECO of 91.45%. [Display omitted] •Mediating heterogenized NiPc into single Ni-N3 moiety for optimizing the poor stability of NiPc-based hybrid catalyst.•The stabilization mechanism and the temperature effect on the structure-activity relationship were systematically discussed.•The optimal catalyst achieved a near-unity electrocatalytic CO2-to-CO conversion, with CO Faradaic efficiency of 98.57%.•A Zn-CO2 rechargeable battery was designed, displaying a peak power density of 0.64 mW cm−2, and a good cyclability of 80 h.