Heterogeneous Cobalt Phthalocyanine/Sulfur‐Modified Hollow Carbon Sphere for Boosting CO2 Electroreduction and Zn–CO2 Batteries

Tuning coordination environment of single‐atom catalysts (SACs) is widely applied for the electrochemical CO2 reduction reaction (CO2RR). However, the influence of the interaction between SACs and support on the catalytic performance are not comprehensive. Herein, taking cobalt phthalocyanine (CoPc) as a conceptual example, a hetero S‐atom doping strategy of hollow carbon sphere (S‐NHC) is put forward as a carrier, revealing the intrinsic relationship between microenvironment regulation and catalytic activity of single Co‐atom. The additional S doping may induce more carbon defect and increases the content of pyrrolic N in the S‐NHC sample, leading to stronger electronic interaction of heterogeneous CoPc/S‐NHC for boosting CO2RR performance. Remarkably, the catalyst achieves a highest CO selectivity of nearly 100% at −0.6 V, and the FECO are over 90% in a wide potential range from −0.4 to −0.8 V in a flow cell. The maximum power density is high as 2.68 mW cm−2 at 4.7 mA cm−2 for the Zn–CO2 battery with CoPc/S‐NHC cathode. In situ attenuated total reflection infrared (ATR‐IR) spectroscopy reveals the formation of key *COOH and *CO intermediates, while the calculation result confirm the optimized Gibbs free energy of these intermediates on CoPc/S‐NHC, suggesting the feasibility of the regulation strategy. A hetero‐S atom doping strategy is first developed to design the heterogeneous CoPc/S‐NC for CO2RR. The advantages of increased carbon defects and pyrrolic N, as well as the optimized free energies of *COOH, *CO, and *H intermediates caused by S doping, leading to the significantly improved performance of CoPc/S‐NC catalyst for CO2 electroreduction and Zn–CO2 battery.