Self-templated synthesis of novel and robust honeycomb-like N-doped highly graphitized carbon from low-temperature carbonization

Abstract

Graphiticity and porosity are two marvelous properties desired in carbon support materials for electrocatalytically active materials. However, simultaneously incorporating the aforementioned properties is deemed incompatible with thermally induced carbon synthesis. A unique approach to realizing carbon materials with such dual properties at the same time is the use of porogen templates. In this study, g-C₃N₄ is pyrolyzed with the aid of metallic Mg to produce highly graphitized N-doped carbon endowed with abundant Mg₃N₂ sites. Notably, the self-generated Mg₃N₂ in the carbon matrix acts as a template for a unique honeycomb-like porous structure after etching of the porogen. Thus, the honeycomb-like N-doped graphitized carbon (HNGC) is found to be an effective support material for anchoring PtCo alloy nanoparticles which improved the mass transport pathways, resulting in a high peak power density in polymer electrolyte membrane fuel cell (PEMFC) operation. In addition, HNGC's high graphiticity enables it to withstand the harsh conditions of the DOE accelerated durability test (ADT), while the N-doping enhances its mass activity (MA), contributing to excellent support durability and catalytic performance.