Nitrogen-doped carbon nanofibers on expanded graphite as oxygen reduction electrocatalysts

Buan, Marthe Emelie Melandsø; Muthuswamy, Navaneethan; Walmsley, John C.; Chen, De; Rønning, Magnus

doi:10.1016/j.carbon.2016.01.081

Cited by 60 publications

(40 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar to commercial CNTs, these three samples exhibit two obvious peaks at approximately 1343 cm −1 and 1584 cm −1 respectively as shown in Figure f. The two pronounced peaks can be attributed to well‐known Disorder (D) bands and Graphitic (G) bands, which are related to sp 2 carbon materials . D band arises from A 1 g vibration mode of carbon owing to defects and heteroatoms disordering the graphitic lattice, while G band arises from the E 2 g vibration mode of C−C stretching signifies highly ordered crystalline carbon .…”

Section: Resultsmentioning

confidence: 76%

Restructured Fe−Mn Alloys Encapsulated by N‐doped Carbon Nanotube Catalysts Derived from Bimetallic MOF for Enhanced Oxygen Reduction Reaction

et al. 2018

View full text Add to dashboard Cite

A set of novel catalysts FeMn/N‐CNTs that partly maintain the core‐shell structure have been prepared successfully by calcination of analogous MOF‐74, which has bimetallic species (Fe and Mn) and a cheap organic ligand (2, 5‐dihydroxylbenzoic acid, DHBA) with melamine as additional nitrogen source. These catalysts exhibit a distinctive microstructure of Fe−Mn alloys surrounded by N‐doped carbon nanotubes (CNTs). Electrochemical methods have been employed to investigate their activity in oxygen reduction reaction (ORR) in alkaline solution. The highest ORR performance of Fe3Mn1/N‐CNTs‐100 shows that the half wave potential is at 0.865 V and the kinetic current density (at 0.9 V) is 1.447 mA cm−2, which are higher than those of commercial Pt/C (0.855 V, 0.946 mA cm−2). In addition, Fe3Mn1/N‐CNTs‐100 is much more durable than commercial Pt/C under the conditions tested. The highly efficient ORR performance may be attributed to the unique microstructure and large surface area with appropriate pore size, as well as to the synergistic effects between the pyridinic N species and the Fe−Nx species that play important roles in ORR in alkaline solution. However, in acid medium, only Fe−Nx species catalyze ORR and pyridinic N species are limited to work as the active sites. This study may prompt others to explore the development of heteroatom‐doped CNTs surrounding particles as efficient catalyst for ORR and fuel cell applications.

show abstract

Section: Resultsmentioning

confidence: 76%

Restructured Fe−Mn Alloys Encapsulated by N‐doped Carbon Nanotube Catalysts Derived from Bimetallic MOF for Enhanced Oxygen Reduction Reaction

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Although Pt-based electrocatalysts suffer from sluggish ORR kinetics, low durability, high price and scarcity, they currently remain the most effective catalyst for proton-exchange membrane fuel cells [1,5]. To this end, it is of immense importance to maximize the activity of the Pt-based catalyst by carefully engineering either its morphology or composition.…”

Section: Introductionmentioning

confidence: 99%

Boosting oxygen reduction and hydrogen evolution at the edge sites of a web-like carbon nanotube-graphene hybrid

Odedairo

Yan

Gao

et al. 2016

Carbon

View full text Add to dashboard Cite

Identifying catalytically active sites in graphene-based catalysts is critical to improved oxygen reduction reaction (ORR) electrocatalysts for fuel-cell applications. To generate abundant active edge sites on graphene-based electrocatalysts for superior electrocatalytic activity, rather than at their basal plane, has been a challenge. A new type of ORR electrocatalyst produced using fluidization process and based on a three-dimensional hybrid consisting of horizontally-aligned carbon nanotube and graphene (CNT-G), featured abundant active edge sites and a large specific surface area (863 m 2 g -1 ). The Pt-doped CNT-G exhibited an increase of about 55% in mass activity over the state-of-the-art commercial Pt/C and about 164% over Pt/N-graphene in acidic medium, and approximately 54% increase in kinetic limiting current than the Pt/C at low overpotential in alkaline medium. The higher mass activity indicates that less Pt is required for the same performance, reducing the cost of fuel cell electrocatalyst. In hydrogen evolution reaction (HER), both the metal-free CNT-G and Pt/CNT-G exhibited superior electrocatalytic activity compared to N-doped graphene and commercial Pt/C, respectively. * Corresponding

show abstract

“…The electrolyte was 0.5 M H 2 SO 4 solution. The potentials were converted to the reversible hydrogen reference electrode (RHE), E RHE = E SCE +0.241+0.0591 pH …”

Section: Methodsmentioning

confidence: 99%

Three‐dimensional Polypyrrole Derived N‐doped Carbon Nanotube Aerogel as a High‐performance Metal‐free Catalyst for Oxygen Reduction Reaction

Zhang

Zhou

2019

ChemCatChem

View full text Add to dashboard Cite

A novel N‐doped carbon nanotube aerogel has been synthesized by pyrolysis of the three‐dimensional tubular polypyrrole networks and evaluated as a metal‐free electrocatalyst for the oxygen reduction reaction. The carbon aerogel catalysts are pyrolyzed at 500 °C (PPy/C‐500), 700 °C (PPy/C‐700), 900 °C (PPy/C‐900) and 1050 °C (PPy/C‐1050), and display the pyrolyzed temperature‐dependent activity and stability. The catalytic activity is increased with the increase of pyrolysis temperature from 500 °C to 1050 °C, ascribed to the high electronically conductive graphitic phases, the thin wall of the three‐dimensional tubular carbon aerogel framework and the increased effective active sites. The nitrogen content is reduced with the increase of pyrolysis temperature, and which plays an important role in the stability of the pyrolyzed catalyst. After 1500 cycles, the PPy/C‐1050 catalyst shows more positive half‐wave potential than the commercial Pt/C catalyst, and displays a quasi‐four‐electron pathway toward the oxygen reduction reaction in the acid solution. This work provides an effective strategy for preparing the low cost and metal‐free N‐doped carbon aerogel catalyst from the conjugated conducting polymer, to achieve high activity and stability.

show abstract

Nitrogen-doped carbon nanofibers on expanded graphite as oxygen reduction electrocatalysts

Cited by 60 publications

References 61 publications

Restructured Fe−Mn Alloys Encapsulated by N‐doped Carbon Nanotube Catalysts Derived from Bimetallic MOF for Enhanced Oxygen Reduction Reaction

Restructured Fe−Mn Alloys Encapsulated by N‐doped Carbon Nanotube Catalysts Derived from Bimetallic MOF for Enhanced Oxygen Reduction Reaction

Boosting oxygen reduction and hydrogen evolution at the edge sites of a web-like carbon nanotube-graphene hybrid

Three‐dimensional Polypyrrole Derived N‐doped Carbon Nanotube Aerogel as a High‐performance Metal‐free Catalyst for Oxygen Reduction Reaction

Contact Info

Product

Resources

About