Active sites for oxygen reduction reaction on nitrogen-doped carbon nanotubes derived from polyaniline

Deng, Haijing; Li, Qian; Liu, Jingjun; Wang, Feng

doi:10.1016/j.carbon.2016.11.014

Cited by 210 publications

(137 citation statements)

References 85 publications

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“…As revealed by the Raman scattering spectra shown in Figure b, a lower intensity ratio between the D and G bands ( I D / I G ) was obtained for GCB, which indicated a much higher graphitization degree for GCB than for CB . In this case, to obtain an accurate I D / I G value, we treated the Raman spectra with a linear baseline subtraction and normalized them with respect to the value of the highest intensity, then deconvoluted to Lorentzian lines . So, we can conclude that the degree of graphitization of the carbon support can substantially promote the formation of the preferred (111) orientation of Co 3 O 4 .…”

Section: Resultsmentioning

confidence: 92%

Tuning the Electronic Bandgap: An Efficient Way To Improve the Electrocatalytic Activity of Carbon‐Supported Co₃O₄ Nanocrystals for Oxygen Reduction Reactions

Liu

Long

Song

et al. 2017

Chemistry A European J

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The achievement of crystal-lattice tuning along low Miller index planes to decrease the bandgap of spinel transition-metal oxides may be an effective way to enhance their electrocatalytic activity for the oxygen reduction reaction (ORR). Herein, we have prepared spherical Co O nanoparticles with a preferred orientation along the (111) plane by direct nucleation and growth of the oxide on graphitized carbon black (GCB). The formation of the preferred (111) oxide is attributed to a unique chemical interaction at the interface between Co O and carbon, which results in covalent C-O-Co bonds in the hybrid. Electrocatalysis experiments in an alkaline environment revealed that the electrocatalytic activity for ORR on the preferred (111) oxide increased as a function of the degree of crystal-lattice orientation, which implies a closely intrinsic correlation between the predominant (111) plane and the catalytic activity. Because Co cations are enriched in this plane, they possess a narrow bandgap and unfilled conduction bands at low energy with respect to Co ions in the preferred (111) Co O , which can contribute to the absorption and activation of active oxygen and lead to improved ORR activity.

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Section: Resultsmentioning

confidence: 92%

Tuning the Electronic Bandgap: An Efficient Way To Improve the Electrocatalytic Activity of Carbon‐Supported Co₃O₄ Nanocrystals for Oxygen Reduction Reactions

Liu

Long

Song

et al. 2017

Chemistry A European J

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“…Above 700 °C, the I D / I G ratio decreases with the temperature, indicating the increase of the graphitization degree. Compared to the other samples, the PPy/C‐1050 catalyst shows a 2D band at 2683 cm −1 , indicating the better graphitization structure of this sample annealed at high temperature . The ordered and graphitic carbon structure obtained at high temperature can improve the electric conductivity of the catalyst materials, and further enhance the ORR activity .…”

Section: Resultsmentioning

confidence: 88%

“…As the temperature continues to rise, the pyridinic N may convert to graphitic N due to the higher stability of the latter . Therefore, the pyridinic N increases first and then decreases, and reaches a minimum at 1050 °C . The graphitic N increases with the increasing temperature, from 13 at% in PPy/C‐500 to 63 at% in PPy/C‐1050.…”

Section: Resultsmentioning

confidence: 97%

“…Figure c shows the XRD patterns of PPy/C‐500, PPy/C‐700, PPy/C‐900 and PPy/C‐1050. The diffraction peaks at around 24° and 43° correspond to (002) and (100) crystal planes of the turbostratic carbon structure . With the increase of pyrolysis temperature, the (002) plane becomes stronger and narrower, and the (100) peak becomes more prominent, implying the increase of degree of graphitization of the carbon catalysts pyrolyzed at higher temperature .…”

Section: Resultsmentioning

confidence: 99%

“…The pyridinic N is at a low level of 9 at% for PPy/C‐500, which increases to 40 at% for PPy/C‐700, and then markedly decreases to 3 at% for PPy/C‐1050. The pyridinic N can be formed when pyrolyzing the organic polymer at >700 °C . As the temperature continues to rise, the pyridinic N may convert to graphitic N due to the higher stability of the latter .…”

Section: Resultsmentioning

confidence: 99%

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

Zhang

Zhou

2019

ChemCatChem

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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.

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Identification and Understanding of Active Sites of Non‐Noble Iron‐Nitrogen‐Carbon Catalysts for Oxygen Reduction Electrocatalysis

Yang

Chen

Zhang

et al. 2023

Adv Funct Materials

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Non-noble iron-nitrogen-carbon (Fe-N-C) catalysts have been explored as one type of the most promising alternatives of precious platinum (Pt) in catalyzing the oxygen reduction reaction (ORR). However, their catalytic ORR activity and stability still cannot meet the requirement of practical applications. Active sites in such catalysts are the key factors determining the catalytic performance. This review gives a critical overview on identification and understanding of active sties of non-pyrolytic and pyrolytic Fe-N-C catalysts in terms of design strategies, synthesis, characterization, functional mechanisms and performance validation. The diversity and complexity of active sites that greatly dominate the progress of Fe-N-C catalysts include Fe-containing sites (Fe-based nanoparticles and single-atom Fe-species) and metalfree sites (heteroatoms doping and defects). Meanwhile, synergistic effects are also discussed in this review with emphasis on the interaction among multiple active sites. Although substantial endeavors have been devoted to develop the efficient Fe-N-C catalysts, some challenges still remain. To facilitate further research on Fe-N-C catalysts toward practical applications, some research perspectives are prospected in the aspects of innovative synthesis methods, active-sites modulation strategies, high-resolution ex situ/in situ/ operando characterization techniques, theoretical calculations, and so on. This review may provide a guideline for identifying and understanding activesites for developing high-performance Fe-N-C catalysts.

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Active sites for oxygen reduction reaction on nitrogen-doped carbon nanotubes derived from polyaniline

Cited by 210 publications

References 85 publications

Tuning the Electronic Bandgap: An Efficient Way To Improve the Electrocatalytic Activity of Carbon‐Supported Co₃O₄ Nanocrystals for Oxygen Reduction Reactions

Tuning the Electronic Bandgap: An Efficient Way To Improve the Electrocatalytic Activity of Carbon‐Supported Co₃O₄ Nanocrystals for Oxygen Reduction Reactions

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

Identification and Understanding of Active Sites of Non‐Noble Iron‐Nitrogen‐Carbon Catalysts for Oxygen Reduction Electrocatalysis

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Active sites for oxygen reduction reaction on nitrogen-doped carbon nanotubes derived from polyaniline

Cited by 210 publications

References 85 publications

Tuning the Electronic Bandgap: An Efficient Way To Improve the Electrocatalytic Activity of Carbon‐Supported Co3O4 Nanocrystals for Oxygen Reduction Reactions

Tuning the Electronic Bandgap: An Efficient Way To Improve the Electrocatalytic Activity of Carbon‐Supported Co3O4 Nanocrystals for Oxygen Reduction Reactions

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

Identification and Understanding of Active Sites of Non‐Noble Iron‐Nitrogen‐Carbon Catalysts for Oxygen Reduction Electrocatalysis

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Tuning the Electronic Bandgap: An Efficient Way To Improve the Electrocatalytic Activity of Carbon‐Supported Co₃O₄ Nanocrystals for Oxygen Reduction Reactions

Tuning the Electronic Bandgap: An Efficient Way To Improve the Electrocatalytic Activity of Carbon‐Supported Co₃O₄ Nanocrystals for Oxygen Reduction Reactions