High-Performance Co-N-C Aerogel Catalyst for Efficient and Durable Oxygen Reduction Reactions

Developing efficient and cost-effective oxygen reduction reaction (ORR) catalysts is crucial for advancing clean energy technologies. In this study, the 3D polypyrrole aerogel was synthesized using methyl orange as a soft template. The subsequent in-situ spatially confined pyrolysis ensures the atomic dispersion of Co-N x active sites while effectively suppressing metal agglomeration. The optimized CoNC-150 catalyst exhibited a high surface area (298.53 m 2 /g) and well-distributed cobalt-coordinated active sites (Co-N 4 ), significantly enhancing ORR performance. Electrochemical evaluations demonstrated an exceptional half-wave potential of 0.886 V, closely approaching that of commercial 20 wt% Pt/C (0.892 V). The catalyst followed a fourelectron transfer pathway, ensuring efficient ORR kinetics. Remarkably, this robust 3D monolithic architecture endows the catalyst with exceptional stability in alkaline media. Long-term durability tests over 40,000 cycles confirmed their remarkable stability, with only a 0.008 V loss in half-wave potential, significantly lower than the 0.022 V loss in Pt/C under similar conditions. The degraded CoNC-150 exhibited a half-wave potential of 0.878 V, significantly outperforming Pt/C (0.870 V). Kinetically, CoNC-150 exhibits a Tafel slope of 146.16 mV/dec, indicating favorable ORR dynamics. These results highlight the potential of CoNC-150 as a highly active and durable non-precious metal catalyst (NPMC) for ORR applications. This study provides valuable insights into the rational design of transition metal-based electrocatalysts, offering a promising route toward scalable and sustainable energy conversion technologies.