fig8
Figure 8. (A, B) Field-emission scanning electron microscopy (FESEM) image of 3D ordered porous ZIF-67 taken from different directions. These figures are quoted with permission from Li et al.[74]. Thin (C) and thick (D) carbon shell models. These figures are quoted with permission from Yoo et al.[109]. (E) Schematic demonstration of Fe-N-C catalyst with NH4Cl treatment and deposit of a carbon layer on the Fe-AC catalyst. (F, G) ORR polarization curves after different cycles AST text in O2-saturated 0.5 H2SO4. These figures are quoted with permission from Liu et al.[46] (H) H2-O2 PEMFCs polarization and power density curves. Cathode, 3.5 mgcat cm-2 for Fe-N-C; anode, 0.4 mgPt cm-2. This figure is quoted with permission from Yin et al.[81].
