Salt-Confined Engineering of Hierarchically Porous Cobalt-Modified Nitrogen-Doped Carbon Architecture as a Cathode Electrocatalyst for Anion Exchange Membrane Fuel Cell

Abstract

Developing durable and scalable non-platinum group metal (non-PGM) cathode catalysts remains a canonical challenge for anion exchange membrane fuel cells (AEMFCs). In this study, we report a hierarchically porous cobalt-modified nitrogen-doped carbon (Co─CoO/NC) electrocatalyst synthesized via salt-confined carbonization of glucose and urea using NaCl as a removable ionic template. Methodical TG-DSC analysis is employed to elucidate the thermal evolution of the precursors, revealing the sequential decomposition of urea, carbonization of glucose, and stabilization of the carbon framework under salt confinement, which has collectively suppressed the aggregation of cobalt nanoparticles during the growth. Structural and spectroscopic characterizations confirm uniformly dispersed, coordination-stabilized cobalt species within a defect-rich yet conductive carbon framework, in Co─CoO/NC. Nitrogen adsorption–desorption measurements show a Type IV isotherm with H3 hysteresis and a high surface area (∼240 m² g⁻¹), indicative of interconnected micro- and meso-pores. The resulting catalyst exhibits enhanced oxygen reduction reaction (ORR) activity and remarkable durability, with minimal loss of its E_1/2 after 15,000 cycles. The MEA fabricated with Co─CoO/NC as cathode catalyst delivered a peak power density of 464 mW cm⁻² in an AEMFC application.