Atomic Fe Dispersed Hierarchical Mesoporous Fe–N–C Nanostructures for an Efficient Oxygen Reduction Reaction

Abstract

Due to the scarcity and high cost of precious metals, the hydrogen economy would ultimately rely on non-platinum-group-metal (non-PGM) catalysts. The non-PGM-catalyzed oxygen reduction reaction, which is the bottleneck for the application of hydrogen fuel cells, is challenging because of the limited activity and durability of non-PGM catalysts. A stabilized single-atom catalyst may be a possible solution to this issue. In this work, we employ a coordination-assisted polymerization assembly strategy to synthesize an atomic Fe and N co-doped ordered mesoporous carbon nanosphere (denoted as meso-Fe–N–C). The meso-Fe–N–C possesses a hierarchical structure with a high surface area of 494.7 m2 g–1 as well as a high dispersion of Fe (2.9 wt %) and abundant N (4.4 wt %). With these beneficial structural properties, the meso-Fe–N–C exhibits excellent activity and durability toward the oxygen reduction reaction, outperforming the state-of-the-art Pt/C electrocatalysts.

Activity Trends and Mechanisms in Peroxymonosulfate‐Assisted Catalytic Production of Singlet Oxygen over Atomic Metal‐N‐C Catalysts

“…X-ray diffractions (XRD) and Raman spectroscopy are performed to detect the similarity of M-SACs.Asexhibited in Figure 1g,t wo broad and weak diffraction peaks at around 258 8 (002, graphite) and 448 8 (101, graphite) can be indexed to the disordered and defective carbon structure. [34] Besides,n o peaks of metal phases can be observed, which is consistent with SEM and TEM results.Asrevealed by Raman spectroscopy (Figure S6 and Table S1), the intensity ratios of Dband to Gband (I D /I G )for the M-SACs and N-C are similar, which indicates that these catalysts have as imilar degree of structural defects. [35,36] Additionally,t he Brunner-Emmet-Te ller (BET) surface area and total pore volume of M-SACs and N-C measured by nitrogen sorption isotherms are all around 800 m 2 g À1 and 2cm 3 g À1 ,r espectively,w hich further identify the similarity on material structural and physicochemical properties (Figure 1h and Figure S7,S8, Table S2).…”

“…X‐ray diffractions (XRD) and Raman spectroscopy are performed to detect the similarity of M‐SACs. As exhibited in Figure 1 g, two broad and weak diffraction peaks at around 25° (002, graphite) and 44° (101, graphite) can be indexed to the disordered and defective carbon structure [34] . Besides, no peaks of metal phases can be observed, which is consistent with SEM and TEM results.…”

Engineering local coordination environments and site densities for high‐performance Fe‐N‐C oxygen reduction reaction electrocatalysis

“…Traditional templates (SiO 2 , 79,81,82 PVP, 83 F127, 84 etc.) have been widely applied to introduce mesopores into carbon supports.…”

Electrospinning Synthesis of Self‐Standing Cobalt/Nanocarbon Hybrid Membrane for Long‐Life Rechargeable Zinc–Air Batteries

“…[4][5][6] However, the complex and sluggish kinetics of oxygen reduction and evolution reactions (ORR/OER) at air electrodes during the discharge/charge process severely limit its electrochemical properties and lead to low power density and unsatisfactory cyclability. [7][8][9] Meanwhile, precious oxygen electrocatalysts, including platinum (Pt) composite and ruthenium (Ru) oxides-based composites, exhibit insufficient bifunctional…”