Highly electroactive N–Fe hydrothermal carbons and carbon nanotubes for the oxygen reduction reaction

Morais, R.G.; Rey‐Raap, Natalia; Figueiredo, José L.; Pereira, M.F.R.

doi:10.1016/j.jechem.2020.03.039

Cited by 16 publications

(8 citation statements)

References 49 publications

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“…The decreasing trend may be due to the heme doping process. It has been reported that pore blockage occurs during the incorporation of FePc . It is reasonable to speculate that the heme doping process could result in pore blockage and the reduction of the SSA, as heme possesses the Fe–N 4 structure similar to FePc.…”

Section: Resultsmentioning

confidence: 96%

Atomically Dispersed Fe–N₅ Sites Anchored on 3D N-Doped Porous Carbon for Efficient Selective Oxidation of Aromatic Alkanes at Room Temperature

Wei

Cai

et al. 2022

ACS Appl. Mater. Interfaces

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On account of the increasing demand for aromatic ketones and the challenging task of mass production in the chemical industry, efficient and sustainable catalysts are urgently needed to catalyze the conversion of aromatic alkyl compounds into high value-added products via the activation of C–H bonds. Herein, Fe single-site atoms anchored on a N-doped three-dimensional (3D) porous carbon nanostructure (Fe-MEG-800) synthesized through the self-assembly hydrothermal method are reported. Detailed characterization analyses, such as aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (AC-HAADF-STEM), are employed to prove the isolated single Fe atom dispersing on the carbon nanostructure, along with X-ray absorption spectroscopy (XAS) and Mössbauer spectroscopy analysis confirming the Fe–N5 coordination structure. Furthermore, the 3D cross-linked structure not only provides an abundant open-framework structure for the mass transfer during the reaction but also facilitates the exposure of more active sites and promotes the reaction procedure. The as-prepared catalyst possesses high catalytic activity toward the C–H bond at room temperature. In the model reaction of oxidizing ethylbenzene (EB) to high-value acetophenone (AcPO), the conversion and the selectivity of the reaction are both over 99%. In addition, the catalyst also presents favorable stability with retaining high performance even after eight cycles. The possible adsorption sites of the reactant and oxidant are explored through density functional theory (DFT) calculations. Based on the analysis of experimental and theoretical results, a possible mechanism for the oxidation of EB to AcPO involving •OH, O2 •–, and 1O2 is also proposed.

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Section: Resultsmentioning

confidence: 96%

Atomically Dispersed Fe–N₅ Sites Anchored on 3D N-Doped Porous Carbon for Efficient Selective Oxidation of Aromatic Alkanes at Room Temperature

Wei

Cai

et al. 2022

ACS Appl. Mater. Interfaces

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“… 27 Furthermore, the methodology involved in the fabrication of the proposed electrode is simpler compared to other electrodes in the literature. 30 − 32 …”

Section: Resultsmentioning

confidence: 99%

“…Furthermore, the electron-extracting effect of the ketonic group of poly( Co (II) TPpPc) has the ability to reduce the electron density on cobalt and minimize the energy gap between the donor poly( Co (II) TPpPc) and acceptor O 2 , leading to an efficient oxygen reduction . Furthermore, the methodology involved in the fabrication of the proposed electrode is simpler compared to other electrodes in the literature. − …”

Section: Resultsmentioning

confidence: 99%

Tetraphenolphthalein Cobalt(II) Phthalocyanine Polymer Modified with Multiwalled Carbon Nanotubes as an Efficient Catalyst for the Oxygen Reduction Reaction

et al. 2022

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Oxygen reduction reaction (ORR) is the main reaction at the cathode of a fuel cell that utilizes Pt/C as the benchmark catalyst. Due to sluggish activity, high cost, rare abundance, and durability issues, Pt/C must be replaced by nonprecious, stable, and easily synthesizable materials. This work involves the synthesis of novel, simple, low-cost, and environmentally friendly phenolphthalein-bearing cobalt(II) phthalocyanine polymer, poly ( Co II TPpPc ) dyad, as an efficient catalyst for ORR. The results of analytical characterizations reveal the formation of the poly ( Co II TPpPc ) polymer in the pure state. To further enhance the catalytic response of poly ( Co II TPpPc ), a hybrid composite is prepared using poly ( Co II TPpPc ) and multiwalled carbon nanotubes (MWCNTs) that increase the surface area and conductivity. The poly ( Co II TPpPc ) and hybrid composite are separately deposited on the electrode surfaces. The electron microscopy images confirm the uniform distribution of the poly ( Co II TPpPc ) molecules on the electrode surface and MWCNTs. The poly ( Co II TPpPc ) and hybrid composite electrodes are evaluated for ORR, and the hybrid composite exhibits better onset potential at 0.803 V versus reversible hydrogen reference electrode for ORR according to linear sweep voltammograms (LSVs). The obtained data are superior compared to those of other carbon-based redox-active materials reported previously and nearer to those of the benchmark catalyst (Pt/C). The rotating disc electrode measurement of the hybrid composite electrode confirms the total number of electrons involved in ORR to be four. Furthermore, the hybrid composite electrode exhibits an excellent stability for 100 LSV scans. The synergistic effect of poly ( Co II TPpPc ) and MWCNTs leads to the surprisingly high ORR activity due to the improved surface area, conductivity, and interfacial confined surface.

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“…In modern materials science, carbon materials with a unique structure, well-defined pores, and micro–nano morphology attracted considerable interest for multiple applications. − Among them, porous carbon spheres (PCSs) with large surface area, good liquidity, and tunable porosity are of great concern for energy storage, the environment, gas adsorption and separation, medicine, and catalysts. − Over the past decades, many efforts have been made on the synthesis and novel applications of PCSs. In order to meet the diversified applications, a large surface area, well-defined pore structure, hierarchical geometry, and structure stability of PCSs are desirable.…”

Section: Introductionmentioning

confidence: 99%

Molecular Level Design of Nitrogen-Doped Well-Defined Microporous Carbon Spheres for Selective Adsorption and Electrocatalysis

Chen

Liu

Huang

et al. 2021

ACS Appl. Mater. Interfaces

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Nitrogen-doped porous carbon spheres have attracted great interest in diversified fields owing to their unique physical and chemical properties. However, the synthesis of nitrogen-doped porous carbon spheres with hierarchical superstructures and refined micropore structures is still a challenge. Herein, we develop a molecular-scale silica templating strategy to prepare nitrogen-doped microporous carbon spheres (MCSSs) with high porosity and a well-defined micropore structure. Octa(aminophenyl) polyhedral oligomeric silsesquioxane is used as a building block in MCSS precursors to provide precise molecular-scale templating and nitrogen doping. The morphology of MCSSs can be easily tuned by choosing the proper solvent. The as-synthesized MCSS with a large surface area (2036 m2 g–1), narrow micropore size distribution, nitrogen doping, and hierarchical geometry can serve as an efficient selective adsorbent for CO2 and organic pollutants. Furthermore, the MCSS decorated with Fe–N–C active sites (MCSS–Fe) shows enhanced electrocatalytic ORR activity in alkaline solution. This novel approach may open a new avenue for controllable fabrication of porous carbon spheres with desired geometry and well-designed pore structure and show potential applications in selective adsorption and catalysis.

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Highly electroactive N–Fe hydrothermal carbons and carbon nanotubes for the oxygen reduction reaction

Cited by 16 publications

References 49 publications

Atomically Dispersed Fe–N₅ Sites Anchored on 3D N-Doped Porous Carbon for Efficient Selective Oxidation of Aromatic Alkanes at Room Temperature

Atomically Dispersed Fe–N₅ Sites Anchored on 3D N-Doped Porous Carbon for Efficient Selective Oxidation of Aromatic Alkanes at Room Temperature

Tetraphenolphthalein Cobalt(II) Phthalocyanine Polymer Modified with Multiwalled Carbon Nanotubes as an Efficient Catalyst for the Oxygen Reduction Reaction

Molecular Level Design of Nitrogen-Doped Well-Defined Microporous Carbon Spheres for Selective Adsorption and Electrocatalysis

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Highly electroactive N–Fe hydrothermal carbons and carbon nanotubes for the oxygen reduction reaction

Cited by 16 publications

References 49 publications

Atomically Dispersed Fe–N5 Sites Anchored on 3D N-Doped Porous Carbon for Efficient Selective Oxidation of Aromatic Alkanes at Room Temperature

Atomically Dispersed Fe–N5 Sites Anchored on 3D N-Doped Porous Carbon for Efficient Selective Oxidation of Aromatic Alkanes at Room Temperature

Tetraphenolphthalein Cobalt(II) Phthalocyanine Polymer Modified with Multiwalled Carbon Nanotubes as an Efficient Catalyst for the Oxygen Reduction Reaction

Molecular Level Design of Nitrogen-Doped Well-Defined Microporous Carbon Spheres for Selective Adsorption and Electrocatalysis

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Product

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Atomically Dispersed Fe–N₅ Sites Anchored on 3D N-Doped Porous Carbon for Efficient Selective Oxidation of Aromatic Alkanes at Room Temperature

Atomically Dispersed Fe–N₅ Sites Anchored on 3D N-Doped Porous Carbon for Efficient Selective Oxidation of Aromatic Alkanes at Room Temperature