CoMn2O4 Anchored on N-Doped High-Dimensional Hierarchical Porous Carbon Derived from Biomass for Bifunctional Oxygen Electrocatalysis

Abstract

There is an emerging interest in developing bifunctional oxygen electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), being key electrochemical reactions that govern the overall performance of unitized regenerative fuel cells and rechargeable metal-air batteries. However, such undertaking has been a huge challenge due to the high cost of noble metals (e.g. Pt, Ir) and their stability when used as catalysts. Herein, we report CoMn2O4 embedded on three-dimensional (3D) hierarchical porous carbon (HPC) derived from waste corn cobs as a possible noble metal-free bifunctional electrocatalyst. The hybrid catalyst is fabricated by solvothermal reaction of as-prepared N-doped 3DHPC and CoMn2O4. The template-free approach in preparing N-3DHPC ensures ample nitrogen doping using melamine to improve electronic conductivity of carbon and formation of three-dimensional, interconnected pore network, which is favorable for CoMn2O4 crystal dispersion. The same hybrid material also presents good OER activity, rendering an active and inexpensive dual-function electrocatalyst.