Iron-decorated nitrogen-rich carbons as efficient oxygen reduction electrocatalysts for Zn–air batteries
A low-cost and scalable method has been developed to synthesize Fe-decorated N-rich carbon electrocatalysts for the oxygen reduction reaction (ORR) based on pyrolysis of metal carbonyls containing metal–organic frameworks (MOFs). Such a method simultaneously optimizes the Fe-related active sites and the porous structure of the catalysts. Accordingly, the best-performing Fe-NC-900-M catalyst shows excellent ORR activity with a half-wave potential of 0.91 V vs. RHE, exceeding that of the 40% Pt/C catalyst in alkaline media. Furthermore, the zinc–air batteries constructed with Fe-NC-900-M as the cathode catalyst exhibit high open-circuit voltage (1.5 V) and peak power density (271 mW cm−2), and outperform most zinc–air batteries with noble-metal free ORR catalysts.