Facile regulation of porous N-doped carbon-based catalysts from covalent organic frameworks nanospheres for highly-efficient oxygen reduction reaction. (15th August 2021)

• Record Type: Journal Article
• Authors: Jiang, Ting; Jiang, Weicun; Li, Yaling; Xu, Yunshi; Zhao, Mingyu; Deng, Mengyuan; Wang, Yi
• Is Part Of: Carbon. Volume 180(2021)
• Page Start: 92
• Page End: 100
• Publication Date: 2021-08-15
• Subjects: Fuel cell -- Covalent organic framework -- Oxygen reduction reaction -- N-doped; Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2021.04.058
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: Exploiting inexpensive, highly active and durable electrocatalysts for highly-efficient oxygen reduction reaction (ORR) remains an urgent need. Herein, uniformed covalent organic frameworks (COFs) nanospheres were prepared as the precursors of N-doped porous carbon-based electrocatalyst for ORR reaction. Investigations into the COF-derived N-doped carbon nanospheres (N–CNS) demonstrated that the porous and crystalline frameworks with precise N positions in COF precursors facilitated the regulation of surface area, conductivity, active sites (defects) and their accessibility (pores) in N–CNS via optimizing the pyrolysis temperature. As a result, an excellent ORR catalyst with the activity mostly approximating to that of the commercial 20 wt% Pt/C catalyst among the reported metal-free N-doped carbon-based catalysts to our best knowledge, was obtained, which also exhibited good durability and excellent methanol tolerance. Moreover, Fe 3+ was facilely coordinated into COF nanospheres, which therefore derived an ultra-small Fe nanoparticles-decorated N–CNS (Fe–N–CNS) by the simple one-step pyrolysis. This Fe–N–CNS can further enhance its ORR activities (onset potentials, half-wave potentials and limit current density) to be comparable with those of 20 wt% Pt/C catalyst via the synergistic Fe–N active sites. Also, it exhibited good durability and methanol tolerance. All these paved a way to derive COF into the carbon-based electrocatalysts for highly-efficient ORR. Graphical abstract: Image 1 Highlights: COF nanospheres were exploited for N-doped porous carbon-based ORR electrocatalyst (N–CNS). Porous/crystalline COF with precise N positions facilitated the regulation of carbon-based catalysts with high activity. Superior ORR performances of N–CNS to most metal-free carbon-based catalysts were achieved. Fe–N–CNS with ultra-small Fe nanoparticles was also prepared by the simple one-step pyrolysis of Fe 3+ -coordinated COF. Fe–N–CNS exhibited the comparable activities and much superior durability/methanol tolerance to those of Pt/C (20 wt%).