The Durability of the Platinum/Polypyrrole Nanotubes' Catalysts in Oxygen Reduction Reaction

Abstract

Platinum (Pt) catalysts supported on carbon-based materials are effective catalysts for fuel cells. However, the durability of the carbon supports in acidic media needs to be improved. Platinum/polypyrrole (PPy) nanotubes have emerged as promising catalysts for the oxygen reduction reaction (ORR) due to their high surface area and good electrocatalytic activity. Furthermore, the nitrogen atoms within the chemical structure of PPy nanotubes are expected to improve their durability.In this study, we investigated the performance and durability of Pt catalysts during ORR by decorating different carbon-based materials with Pt nanoparticles. The catalytic activity and durability were analyzed using the rotation ring-disk electrode (RRDE) technique. We also examined the influence of the different supports on the electrochemical degradation of the catalysts.Our results showed that Pt/PPy nanotubes exhibited high activity and durability in ORR reactions. We paid particular attention to the chemical changes of the catalysts' surfaces, including both the metal and support components, during the ex-situ electrochemical measurements. The surface of the catalysts was characterized using photoelectron X-ray spectroscopy (XPS), synchrotron radiation photoelectron spectroscopy (SRPES), and near-edge X-ray absorption fine structure (NEXAFS) analysis before and after electrochemical degradation. Based on our findings, we proposed degradation mechanisms of the Pt/PPy nanotubes catalysts.In addition, we tested the Pt/PPy nanotubes catalysts in fuel cells and observed their high performance. These findings suggest that Pt/PPy nanotubes catalysts can serve as durable and effective catalysts for ORR reactions, even under harsh conditions. Further research is needed to optimize the synthesis conditions and operating parameters of these catalysts to improve their performance and durability.