fig7

Figure 7. (A and B) Schematic diagram of fabrication (A) and XRD spectrum(B) of Fe₁-N₄-C SAC and Fe₂-N₆-C DAC; (C and D) LSV curves (C) and FE_CO test (D) of different Fe_x-N_y-C catalysts; (A-D) are quoted with permission from Wang et al.^[158]; (E) Structure diagram of Fe₂NPC; (F and G) FE_CO (F) and J_CO (G) of Fe₂NPC and other reference catalysts; (E-G) are quoted with permission from Zhao et al.^[159]. SACs: Single-atom catalysts; DACs: dual-atom catalysts; RHE: reversible hydrogen electrode; XRD: X-ray diffraction; LSV: linear sweep voltammetry; FE_CO: Faradaic efficiency for CO.