Sub‐50 nm Iron–Nitrogen‐Doped Hollow Carbon Sphere‐Encapsulated Iron Carbide Nanoparticles as Efficient Oxygen Reduction Catalysts

Abstract

Sub‐50 nm iron–nitrogen‐doped hollow carbon sphere‐encapsulated iron carbide nanoparticles (Fe3C‐Fe,N/C) are synthesized by using a triblock copolymer of poly(styrene‐b‐2‐vinylpyridine‐b‐ethylene oxide) as a soft template. Their typical features, including a large surface area (879.5 m2 g−1), small hollow size (≈16 nm), and nitrogen‐doped mesoporous carbon shell, and encapsulated Fe3C nanoparticles generate a highly active oxygen reduction reaction (ORR) performance. Fe3C‐Fe,N/C hollow spheres exhibit an ORR performance comparable to that of commercially available 20 wt% Pt/C in alkaline electrolyte, with a similar half‐wave potential, an electron transfer number close to 4, and lower H2O2 yield of less than 5%. It also shows noticeable ORR catalytic activity under acidic conditions, with a high half‐wave potential of 0.714 V, which is only 59 mV lower than that of 20 wt% Pt/C. Moreover, Fe3C‐Fe,N/C has remarkable long‐term durability and tolerance to methanol poisoning, exceeding Pt/C regardless of the electrolyte.

Controlled Synthesis of a Vacancy‐Defect Single‐Atom Catalyst for Boosting CO2 Electroreduction

“…The high-resolution TEM image exhibits obvious lattice fringes with spacing of 0.34 nm (Figure 1f), which can be assigned to the (002) plane of graphitic carbon. [31] Furthermore,t he HAADF-STEM image of Ni-N 3 -V shows abundant pores,as noted by red circles in the Supporting Information, Figure S6. Thes ize of the pores is about 1nm, corresponding well with the pore diameter distributions obtained from N 2 sorption isotherm ( Figure 1h).…”

Self‐Assembly Synthesis of Mulberry‐Like Fe/N/S‐Doped Highly Porous Carbon Materials: Efficient and Stable Catalysts for Oxygen Reduction Reaction

“…Heteroatom (Fe, Co, N, B, P and S) doped carbon nanomaterials exhibit amplified physicochemical properties, e. g. excellent electronic and thermal conductivity, low density, high chemical reactivity and stability, etc . Porosity as one of the most important attributes of carbon nanomaterials facilitates the mass transport and enlarges the surface area . As a result, the heteroatom doped nanoporous carbon materials (NCMs) have been widely researched and applied in catalysis, drug delivery, separation, energy conversion/storage, and many other fields .…”

“…[7][8][9][10][11][12] As a result, the heteroatom doped nanoporous carbon materials (NCMs) have been widely researched and applied in catalysis, drug delivery, separation, energy conversion/storage, and many other fields. [13][14][15][16][17][18][19][20] Despite the great development, there are still some challenges of synthesizing these carbon materials, for instance, reducing the pollution caused by the carcinogenic carbon resources or toxic reagents used in template removal, designing the structure, morphology, and chemical composition easily and efficiently, and so on. Dopamine (DA) is a kind of widespread, green and sustainable biomolecule with catechol and amine groups that can effectively bind with most organic and inorganic species.…”

Metal‐Tuned Acetylene Linkages in Hydrogen Substituted Graphdiyne Boosting the Electrochemical Oxygen Reduction

“…Two‐dimensional graphene, including graphene oxide and reduced graphene, as a promoter or supporter for nanoparticles, is an important milestone toward the development of efficient nanocatalysts 1,2. Benefiting from the large specific surface area and high electrical conductivity,3,4 graphene enables high loading of nanoparticles onto separate sites of 2D sheets, which allows catalytically active species free from agglomeration and retains the stability of nanostructure in various electrolyte solutions, thus prolonging the lifespan of catalyst 2,5–8. The high conductivity of graphene facilitates charge transport between catalyst surface and reaction intermediates 2.…”

“…The engineering of strong interactions plays a critical role in tuning electronic state of supporters and supported species for facilitating catalysis process 11–13. Although some defect and functionalization strategies have been introduced,8,14–17 engineering the strong interactions to enhance the catalytic activity of graphene‐supported compounds is still far from being controllable and tunable.…”