Advancing the Stability of Carbon-Based Catalysts for Long-Lasting Oxygen Reduction Reactions

Achieving high-performance carbon-based catalysts for the oxygen reduction reaction (ORR) is pivotal for advancing sustainable energy technologies. Despite significant advancements in ORR activity, the intrinsic instability of carbon frameworks and active sites under harsh operating conditions remains a fundamental challenge. Although the degradation of carbon under ORR conditions has long been recognized, previous reviews and research works dominantly focus on improving catalytic activity, whereas the stability issue, which is decisive for practical applications, is largely neglected or treated superficially, thus impeding the commercialization of carbon ORR catalysts. In this review, efforts are made to clarify carbon degradation pathways and the underlying mechanisms, including the oxidation of carbon frameworks, demetallation of metal-active sites, protonation of active sites, attack of reactive oxygen species (ROS), and micropore flooding. The strategies to mitigate carbon degradation are also systematically analyzed. By integrating theoretical modulations with experimental results, significant insights are gained into the trade-off between activity and stability. Importantly, valuable perspectives and implementable strategies are proposed to construct efficient carbon catalysts with high catalytic activity and stability. This work provides a big picture of carbon ORR catalyst degradation, aiming to bridge the gap between laboratory research and real-world electrocatalyst deployment.