Mn-Pyridine N site-enriched Mn-N–C derived from covalent organic polymer for electrochemical oxygen reduction and capacitive storage

A new Mn-pyridine covalent organic polymer combining on carbon nanotubes and graphenes was thermally converted into porous Mn-N–C materials with high graphitization degree. It was found to be highly active electrocatalysts for oxygen reduction reaction (ORR) in both alkaline and acidic media. The ORR half-wave potential reached 0.87 V in 0.1 M KOH and 0.62 V in 0.1 M HClO4, together with a high Zn-air battery power density of 141 mW cm−2. It also demonstrated an impressive capacitive storage performance in alkaline and acidic media, with a reversible capacitance of 408 F‧g−1 in 6 M KOH and 310 F‧g−1 in 2.0 M H2SO4. The abundant Mn-Nx sites coordinating to pyridine N atoms and few MnO nanoparticles contributed to its efficient ORR catalytic activity and better capacitive storage performance.