Nano-engineered directed growth of Mn3O4 quasi-nanocubes on N-doped polyhedrons: Efficient electrocatalyst for oxygen reduction reaction

Abstract

Engineering the morphology of integral building blocks is a key step in broadening their catalytic activities. In this work, an interesting structure is reported by oriented and directed growth of manganese oxide (Mn3O4) quasi-nanocubes on nitrogen doped mesoporous carbon polyhedrons resulting from zeolite imidazole framework (ZIF-8). The prepared Mn3O4/NCP (Mn3O4 quasi-nanocubes on the surface of N-doped carbon polyhedrons) hybrid catalyst showed activity and durability comparable to Pt/C and higher than nitrogen-doped carbon polyhedrons (NCP) and pure Mn3O4. Further studies indicate that oxygen reduction reaction (ORR) is carried out via a four electron transfer mechanism with very low production of hydrogen peroxide (3%). In this perspective, Mn3O4/NCP is an auspicious nominee as a cathodic catalyst because of inexpensive Mn and good durability. Our synthetic strategy may open a new avenue for material synthesis.