Porous Nitrogen-Doped Carbon Supported Pt Nanocatalyst for Efficient Oxygen Reduction Reactions

Abstract

Oxygen reduction reaction (ORR) at catalyst surface is the key kinetic limiting step in fuel cells that influence the overall cell performance in the energy conversion process. Rational design of the carbon supports with unique morphology and controllable porosity is challenging and significant for efficient and durable oxygen reduction electrocatalysis. Nitrogen-doped carbon nanospheres with uniform size and precise control over mesopores and micropores have been derived from mussel-inspired biomimetic polydopamine through a facile colloidal synthesis method and subsequent high-temperature pyrolysis. The unique surface structure of this nitrogen-doped carbon also dictated the morphologies of the deposited platinum nanoparticles, alleviating the particle dissolution, detachment, and agglomeration issue, which are main factors for catalyst degradation in working conditions. The ORR activity and durability of this electrocatalysts were studied in both rotational disk electrode (RDE) system and membrane electrode assembly (MEA), and a detailed structure-property relationship between porosity of carbon supports, Pt morphologies and fuel cell ORR performance was uncovered. This work is informative to researchers working in electrochemical materials field for developing efficient and robust electrocatalyst supports. Acknowledgement: This research was supported by the Hydrogen and Fuel Cell Technologies Office (HFTO), Office of Energy Efficiency and Renewable Energy, US Department of Energy (DOE) through the Million Mile Fuel Cell Truck (M2FCT) consortium, technology managers G. Kleen and D. Papageorgopoulos.