Mehmood, Asad Ali, Basit Gong, Mengjun Kim, Min Gyu Kim, Ji-Young Bae, Jee Hwan Kucernak, Anthony Kang, Yong-Mook Nam, Kyung-Wan 2024-01-19T14:02:17Z 2024-01-19T14:02:17Z 2021-09-04 2021-08 0021-9797 https://pubs.kist.re.kr/handle/201004/116587 Nitrogen-doped porous carbons containing atomically dispersed iron are prime candidates for substituting platinum-based catalysts for oxygen reduction reaction (ORR) in fuel cells. These carbon catalysts are classically synthesized via complicated routes involving multiple heat-treatment steps to form the desired Fe-Nx sites. We herein developed a highly active Fe-N-C catalyst comprising of exclusive FeNx sites by a simplified solid-state synthesis protocol involving only a single heat-treatment. Imidazole is pyrolyzed in the presence of an inorganic salt-melt resulting in highly porous carbon sheets decorated with abundant Fe-Nx centers, which yielded a high density of electrochemically accessible active sites (1.36 x 1019 sites g-1) as determined by the in situ nitrite stripping technique. The optimized catalyst delivered a remarkable ORR activity with a half-wave potential (E1/2) of 0.905 VRHE in alkaline electrolyte surpassing the benchmark Pt catalyst by 55 mV. In acidic electrolyte, an E1/2 of 0.760 VRHE is achieved at a low loading level (0.29 mg cm-2). In PEMFC tests, a current density of 2.3 mA cm-2 is achieved at 0.90 ViR-free under H2-O2 conditions, reflecting high kinetic activity of the optimized catalyst. (c) 2021 Elsevier Inc. All rights reserved. English ACADEMIC PRESS INC ELSEVIER SCIENCE Development of a highly active Fe-N-C catalyst with the preferential formation of atomic iron sites for oxygen reduction in alkaline and acidic electrolytes Article 10.1016/j.jcis.2021.03.081 1 JOURNAL OF COLLOID AND INTERFACE SCIENCE, v.596, pp.148 - 157 JOURNAL OF COLLOID AND INTERFACE SCIENCE 596 148 157 N scie scopus 000645630200002 2-s2.0-85103795888 Chemistry, Physical Chemistry Article METAL ELECTROCATALYST CARBON PERFORMANCE POLYANILINE EFFICIENT ELECTROREDUCTION MELAMINE DENSITY FE/N/C STABILITY Non-precious metal catalysts Fe-N-C Fuel cells Oxygen reduction reaction Site density