An N-doped porous carbon network with a multidirectional structure as a highly efficient metal-free catalyst for the oxygen reduction reaction

• Published in: Nanoscale 2019-01, Vol.11 (5), p.2423-2433
• Main Authors: Han, Hyunsu, Noh, Yuseong, Kim, Yoongon, Jung, Won Suk, Park, Seongmin, Kim, Won Bae
• Format: Article
• Language: English
• Subjects: Carbon; Catalysis; Catalysts; Fuel cells; Gluconic acid; Mass production; Oxygen reduction reactions; Platinum; Porosity; Porous materials; Sodium salts
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c8nr10242b

Metal-free catalysts have gained substantial attention as a promising candidate to replace the expensive platinum (Pt) catalysts for the oxygen reduction reaction (ORR) which is a key process in low temperature fuel cells. Development of highly efficient and mass-producible N-doped carbon catalysts, however, remains to be a great challenge. In this study, N-doped porous carbon (NPC) materials were synthesized via a simple, cost-effective and scalable method for mass production by using the d -gluconic acid sodium salt, pyrrole, Triton X-100 and KOH. The resulting NPC possessed a multidirectional porous carbon network ( S BET : 1026.6 m 2 g −1 , V t : 1.046 cm 3 g −1 ) with hierarchical porosity and plenty of graphitic N species (49.1%). Electrochemical tests showed that the NPC itself was highly active for the ORR under alkaline and acidic conditions via a four electron pathway for the complete reduction of O 2 in water. More importantly, this NPC catalyst demonstrated better performance than commercial Pt/C catalysts in terms of long-term durability and methanol tolerance under both conditions. A highly efficient multidirectional N-doped porous carbon network with plenty of graphitic N-species has been explored as cathode catalysts in fuel cells.