Proton Transport Functionality-Enabled Carbon Support for Improved Fuel Cell Performance and Durability

A novel Monarch carbon material with proton conduction capability due to the presence of sulfone/sulfoxide/sulfonic groups on the surface was evaluated as a potential cathode catalyst support to enable an electrode design with low ionomer content in proton exchange membrane (PEM) fuel cells. X-ray photoelectron spectroscopy of the carbon support confirmed the sulfonic acid functionality, while dynamic vapor sorption measurements proved higher water uptake. Electrochemical impedance spectroscopy of the PtCo/Monarch electrodes showed higher proton conductivity than state-of-the-art PtCo/C with decreasing ionomer to carbon (I/C) content due to the presence of sulfonic acid functional groups on the carbon support surface. Fuel cell performance and durability measurements showed better high-current density performance for PtCo/Monarch with a 75% lower ionomer content in the electrode compared to that of PtCo/C. Our studies indicate that Monarch carbon could be a viable alternative support for PEM fuel cell catalyst applications.