Synthesis of Fully Exposed Pt Nanoparticles on a 2D Mesoporous Graphitic Nanocarbon Framework for the Oxygen Reduction Reaction.

Abstract

The durability of proton-exchange membrane fuel cells is often compromised by the corrosion of carbon supports in oxygen reduction reaction (ORR) cathodes under harsh operating conditions, including high oxygen concentration, elevated humidity, low pH, and high potentials. To overcome this limitation, we report the synthesis of a 2D mesoporous graphitic nanocarbon framework (MGF) via chemical etching and high-temperature graphitization. The resulting MGF features a monolayer, highly ordered nanoframe architecture that offers enhanced structural stability and conductivity. Leveraging these structural advantages, we designed fully exposed Pt nanoparticles anchored on the MGF (Pt@MGF) as a model system to investigate the interplay between graphitization degree, pore architecture, and electrocatalytic performance. Among the variants, Pt@MGF-1200, synthesized at 1200 °C, demonstrates optimized mesopore confinement and strong Pt-carbon interactions. This results in superior electrochemical durability and ORR activity, positioning Pt@MGF-1200 as a promising alternative to conventional Pt/C catalysts.