Fig. 4: Electrocatalytic ORR performance.
From: Multilayer stabilization for fabricating high-loading single-atom catalysts
a ORR polarization curves, b Tafel plots, and c electron-transfer number (n) (top) and H2O2 yield (bottom) for the Fe-SA-NC, Fe-SA-NSC, Fe-SA-NSFC, and Pt/C in 0.1 M KOH solution. d ORR polarization curves of the Fe-SA-NSFC before and after 25000 CV cycles; the inset of d shows the i–t curve at 0.9 V and 1600 r.p.m. for 25,000 s. e ORR polarization curves and f electron-transfer number (n) (top) and H2O2 yield (bottom) for the Fe-SA-NC, Fe-SA-NSC, Fe-SA-NSFC, and Pt/C in 0.1 M HClO4 solution with rotation speed of 900 r.p.m. g Proposed 4e− reduction mechanism in alkaline solution for the ORR on Fe-SA-NSFC; the inset shows the structure of the Fe-SA-NSFC. h Free energy diagram for the Fe-SA-NC, Fe-SA-NSC, and Fe-SA-NSFC (U = 0 V vs. RHE, pH 13). i OH* binding energies and Mulliken charges of the FeN4 active centres in the Fe-SA-NC, Fe-SA-NSC, and Fe-SA-NSFC.
