Design and synthesis of conductive carbon polyhedrons enriched with Mn-Oxide active-centres for oxygen reduction reaction

Abstract

The development of efficient, low-cost and stable electrocatalysts as the alternative to platinum for the oxygen reduction reaction (ORR) is of significance for many important electrochemical devices, such as fuel cells and metal–air batteries. Herein we discuss the design and synthesis of a MnxOy/N-C hybrid catalyst that can address both the activity and durability issues caused by the high productivity of peroxide (H2O2) in nitrogen-doped carbon (N-C). The high activity and stability of the MnxOy/N-C-3 catalyst is ascribed to its novel hybrid structure, in which MnxOy is a good catalyst for decomposition of peroxide, while N-C not only catalyses the ORR but also prevents MnxOy agglomeration. RRDE study indicates a typical 4-electron ORR pathway with very low peroxide production (∼1.9%) and considerable stability. In light of the low cost and high earth abundance of Mn, the highly active MnxOy/N-C is a promising candidate to be used as a cathode material in metal–air batteries and alkaline fuel cells.