Yoon, Ho Seok Lim, Bo Young Park, Hee Young Kim, Soo-Kil Jung, Won Suk 2024-01-19T08:30:25Z 2024-01-19T08:30:25Z 2023-11-01 2023-11 1572-6657 https://pubs.kist.re.kr/handle/201004/113127 The primary challenge in the large-scale production of metal-air batteries or fuel cells is the high cost of Pt, which is used in the oxygen reduction reaction. To address this issue, we synthesized non-precious metal catalysts by doping Fe, N, and S in various sequences. X-ray diffraction and Raman spectroscopy proved that these catalysts had a higher degree of graphitization than carbon black. While the Fe3C phase was found in the catalyst without S, it was absent in all Fe-NSC catalysts. Imaging and X-ray absorption near edge structure (XANES) studies showed atomically dispersed Fe metal in the S-doped non-precious metal catalysts. X-ray photoelectron spectroscopy (XPS) and XANES reveal that the active site concentrations, inactive Fe-S bond, and oxidation number of the Fe species vary according to the N and S doping sequences. Fe-NSC-1 showed fast kinetics and high selectivity, with an onset potential of 0.96 V. Even after 10,000 potential cycles between 0.6 and 1.0 V, the half-wave potential for Fe-NSC-1 decreased by only 3%. Additionally, the Fe-NSC-1 catalyst showed a negligible decrease in current density during the methanol tolerance tests. Overall, this study found that the doping sequence plays a vital role in enhancing the electrochemical performance and stability of these catalysts under suitable operating conditions by influencing their chemical and electronic structures. English Elsevier BV Modifying electronic and physical properties of Fe-NSC catalyst for oxygen reduction reaction via sulfur doping process Article 10.1016/j.jelechem.2023.117813 1 Journal of Electroanalytical Chemistry, v.948 Journal of Electroanalytical Chemistry 948 N scie scopus 001082062500001 2-s2.0-85172326203 Chemistry, Analytical Electrochemistry Chemistry Electrochemistry Article NONPRECIOUS METAL-CATALYSTS N-C CATALYSTS CARBON NANOTUBES POROUS CARBON ACTIVE-SITES ELECTROCATALYSTS IRON EVOLUTION GRAPHENE ALKALINE Non-precious metal catalysts Single atom catalysts Heteroatom doped carbon material Oxygen reduction reaction