CoN2O2 sites in carbon nanosheets by template-pyrolysis of COFs for CO2RR

• The atomic CoN 2 O 2 sites have been first constructed for CO 2 RR via template pyrolysis of COFs. • The catalyst had abundant CoN 2 O 2 sites with a Co content of 4.27 wt.%. • The catalyst showed a remarkable catalytic activity and selectivity towards CO 2 RR. Electrocatalytic CO 2 reduction (CO 2 RR) is critical in addressing CO 2 emissions. Single atom catalysts, are attracting considerable attention for CO 2 RR because of their high atom utilization efficiencies and tailored electron states. However, the catalytic sites remain limited and developing novel catalytic centers is a significant and challenge. Herein, for the first time, we fabricated CoN 2 O 2 sites in 2D carbon for use in CO 2 RR via template pyrolysis of covalent organic frameworks (COFs). After forming the COF on the surface of Mg/Al-LDH, the obtained catalyst displayed a layered morphology with a thickness of approximately 36 nm and had abundant CoN 2 O 2 sites (4.27 wt.% Co). The catalyst showed a remarkable catalytic activity towards CO 2 RR, with Faradaic efficiencies of 80.2–96.5% at applied potentials between −0.6 and −1.0 V. Theoretical calculations showed that the CoN 2 O 2 sites favor the stretching and cleavage of COOH* at the Co active centers, accelerating the rate-determining step of COOH* formation.