Exploring the Catalytic Activity of Metal-Free Heteroatom-Doped Carbon Nanotubes in Oxygen Reduction Reactions

Abstract: This study investigates the catalytic activity and stability of heteroatom-doped carbon nanotubes (CNTs) in oxygen reduction reactions (ORR), a pivotal process in fuel cell technology. Addressing the critical need for efficient, durable, and cost-effective ORR catalysts, the research specifically explores the effects of nitrogen, boron, and sulfur doping on the electrochemical performance of CNTs. Employing a systematic research design, CNTs were synthesized and doped with the selected heteroatoms through chemical vapor deposition. The doped CNTs underwent comprehensive characterization followed by electrochemical analysis using cyclic voltammetry and linear sweep voltammetry to evaluate ORR activity. The Tafel extrapolation method provided further insights into the kinetic parameters, enhancing the understanding of the electrocatalytic mechanisms at play. Key findings reveal that nitrogen-doped CNTs exhibit superior ORR activity and stability, evidenced by the most positive half-wave potentials, lowest Tafel slopes, and highest exchange current densities among the dopants studied. Additionally, nitrogen-doped CNTs demonstrated remarkable durability and resistance to poisoning, making them highly suitable for long-term fuel cell applications. This research fills a significant gap in the comparative analysis of heteroatom-doped CNTs for ORR, offering valuable insights for the development of next-generation electrocatalysts. The implications of this study extend to advancing fuel cell technologies, contributing to the broader adoption of clean and renewable energy sources