Tri(Fe/N/F)-doped mesoporous carbons as efficient electrocatalysts for the oxygen reduction reaction

• Published in: Applied surface science Vol. 487; pp. 389 - 397
• Main Authors: Lee, Young-Geun, Ahn, Hyo-Jin
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2019
• Subjects: Long-term stability; Non-precious metal electrocatalysts; Oxygen reduction reaction; Specific surface area; Tri-doped mesoporous carbons; Non-precious metal electrocatalysts; Specific surface area; Oxygen reduction reaction; Tri-doped mesoporous carbons; Long-term stability
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2019.05.095

In recent years, advanced designs of non-precious electrocatalysts, such as those with transition metals and heteroatoms into iron‑nitrogen-doped mesoporous carbon, have been actively studied to replace precious-metal electrocatalysts for oxygen reduction reaction (ORR), which are used by future energy storage and conversion devices such as metal-air batteries and fuel cells. In the present study, we propose a noble non-precious electrocatalyst through the introduction of fluorine into iron‑nitrogen doped mesoporous carbon. To this end, we synthesized Tri(Fe/N/F)-doped mesoporous carbon nanofiber (MCNF) using electrospinning, the precursor coating method, and carbonization. Tri(Fe/N/F)-doped MCNFs exhibited an improved onset potential of ~0.9 V, the half-wave potential of ~0.82 V, and limiting-current density of −4.76 mA cm−1, with a four-electron pathway. In addition, Tri(Fe/N/F)-doped MCNFs showed remarkable long-term stability and endurance of methanol-crossover. Therefore, Tri(Fe/N/F)-doped MCNFs exhibited improved ORR performance, which could be explained by the increased specific surface area by mesoporous structures and improved oxygen adsorption by the synergy effects by Fe-Nx macrocycles and a high pyridinic- and pyrrolic-N species resulting from F doping. [Display omitted] •Tri-doped mesoporous carbon as electrocatalyst for oxygen reduction reaction•Tri-dopants such as Fe, N, and F and mesoporous structure in the carbon matrix•Enhanced electrocatalytic active sites and oxygen adsorption•Improved oxygen reduction reaction activities and superior long-term stability