Highly Exposed Active Sites of Fe/N Co‐doped Defect‐rich Graphene as an Efficient Electrocatalyst for Oxygen Reduction Reaction

Oxygen reduction reaction (ORR) provides a vital role for microbial fuel cells (MFCs) due to its slow reaction kinetics compared with the anodic oxidation reaction. How to develop new materials with low cost, high efficacy, and eco-friendliness which could replace platinum-based electrocatalysis is a challenge that we have to resolve. In this work, we accomplished this successfully by means of a facile strategy to synthesize a metallic organic framework-derived Fe, N, S co-doped carbon with FeS as the main phase. The Fe/S@N/C-0.5 catalyst demonstrated outstandingly enhanced ORR activity in neutral PBS and alkaline media, compared to that of commercial 20% Pt-C catalyst. Here, we started-up and operated two parallel single-chamber microbial fuel cells of an air cathode, and those cathode catalysts were Fe/S@N/C-0.5 and commercial Pt-C (20% Pt), respectively. Scanning electron microscopy (SEM) elaborated that the Fe/S@N/C-0.5 composite did not change the polyhedron morphology of ZIF-8. According to X-ray diffractometry(XRD) curves, the main crystal phase of the resulted Fe/S@N/C-0.5 was FeS. The chemical environment of N, S, and Fe which are anticipated to be the high-efficiency active sites of ORR for MFCs were investigated by X-ray photoelectron spectroscopic(XPS). Nitrogen adsorption/desorption techniques were used to calculate the pore diameter distribution. In brief, the obtained Fe/S@N/C-0.5 material exhibited a pronounced reduction potential at 0.861 V (versus Reversible Hydrogen Electrode(RHE)) in 0.1M KOH solution and –0.03 V (vs. SCE) in the PBS solution, which both outperform the benchmark platinum-based catalysts. Fe/S@N/C-0.5-MFC had a higher Open Circuit Voltage(OCV) (0.71 V), stronger maximum power density (1196 mW/m2), and larger output voltage (0.47 V) than the Pt/C-MFC under the same conditions.

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Identifying active sites of boron nitrogen co-doped carbon materials for the oxygen reduction reaction to hydrogen peroxide

Journal of Colloid and Interface Science ◽

10.1016/j.jcis.2021.06.068 ◽

2021 ◽

Author(s):

Xueyan Li ◽

Xingpu Wang ◽

Guozheng Xiao ◽

Ying Zhu

Keyword(s):

Hydrogen Peroxide ◽

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

Active Sites ◽

Carbon Materials ◽

Reduction Reaction ◽

Co Doped ◽

Boron Nitrogen

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Facilitating the acidic oxygen reduction of Fe-N-C catalysts by fluorine-doping

Materials Horizons ◽

10.1039/d1mh01307f ◽

2021 ◽

Author(s):

Xiafang Tao ◽

Ruihu Lu ◽

Lingmei Ni ◽

Vladislav Gridin ◽

Samir Al-Hilfi ◽

...

Keyword(s):

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

Active Sites ◽

Reduction Reaction ◽

Fluorine Doping ◽

Carbon Catalysts ◽

Co Doped

As the alternatives of expensive Pt-based materials for the oxygen reduction reaction (ORR), iron/nitrogen co-doped carbon catalysts (FeNC) with dense FeNx active sites are promising candidates to promote the commercialization...

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A nitrogen and sulfur co-doped iron-based electrocatalyst derived from iron and biomass ligand towards the oxygen reduction reaction in alkaline media

Dalton Transactions ◽

10.1039/d1dt01873f ◽

2021 ◽

Vol 50 (39) ◽

pp. 13943-13950

Author(s):

Haiyan Zhao ◽

Li Chen ◽

Yinghao Xu ◽

He Wang ◽

Jia-Yi Li ◽

...

Keyword(s):

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

Performance Improvement ◽

Alkaline Solution ◽

Active Sites ◽

Reduction Reaction ◽

Alkaline Media ◽

Iron Salt ◽

Iron Based ◽

Co Doped

A N,S-doped Fe-based electrocatalyst was mainly derived from the iron salt and biomass ligand. The single atomic Fe-based active sites and S-doped carbon matrixes cause the performance improvement of the oxygen reduction reaction in an alkaline solution.

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Clarification of Active Sites for Oxygen Reduction Reaction on Silver and Nitrogen Co-Doped Carbon Materials

ECS Meeting Abstracts ◽

10.1149/ma2020-02372399mtgabs ◽

2020 ◽

Vol MA2020-02 (37) ◽

pp. 2399-2399

Author(s):

Ivar Kruusenberg ◽

Anton Kuzmin ◽

Bagrat A. Shainyan ◽

Jin-Song Hu ◽

Digby D. Macdonald

Keyword(s):

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

Active Sites ◽

Carbon Materials ◽

Reduction Reaction ◽

Co Doped

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Nitrogen and sulphur co-doped crumbled graphene for the oxygen reduction reaction with improved activity and stability in acidic medium

Journal of Materials Chemistry A ◽

10.1039/c6ta00073h ◽

2016 ◽

Vol 4 (16) ◽

pp. 6014-6020 ◽

Cited By ~ 30

Author(s):

Siddheshwar N. Bhange ◽

Sreekuttan M. Unni ◽

Sreekumar Kurungot

Keyword(s):

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

Acidic Medium ◽

Active Sites ◽

Reduction Reaction ◽

Acidic Conditions ◽

Co Doped

A crumbled graphene structure with heteroatom doped active sites derived through the pyrolysis of polyethylenedioxythiophene served as an efficient platinum-free electrocatalyst for oxygen reduction under acidic conditions.

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N and S Co-doped Ordered Mesoporous Carbon: An Efficient Electrocatalyst for Oxygen Reduction Reaction in Microbial Fuel Cells

Current Nanoscience ◽

10.2174/1573413716666191231094731 ◽

2020 ◽

Vol 16 (4) ◽

pp. 625-638

Author(s):

Leila Samiee ◽

Sedigheh Sadegh Hassani

Keyword(s):

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

Microbial Fuel Cells ◽

Carbon Materials ◽

Reduction Reaction ◽

Carbon Substrate ◽

Promising Candidate ◽

X Ray ◽

Carbon Framework ◽

Co Doped

Background: Porous carbon materials are promising candidate supports for various applications. In a number of these applications, doping of the carbon framework with heteroatoms provides a facile route to readily tune the carbon properties. The oxygen reduction reaction (ORR), where the reaction can be catalyzed without precious metals is one of the common applications for the heteroatom-doped carbons. Therefore, heteroatom doped catalysts might have a promising potential as a cathode in Microbial fuel cells (MFCs). MFCs have a good potential to produce electricity from biological oxidization of wastes at the anode and chemical reduction at the cathode. To the best of our knowledge, no studies have been yet reported on utilizing Sulfur trioxide pyridine (STP) and CMK-3 for the preparation of (N and S) doped ordered porous carbon materials. The presence of highly ordered mesostructured and the synergistic effect of N and S atoms with specific structures enhance the oxygen adsorption due to improving the electrocatalytic activity. So the optimal catalyst, with significant stability and excellent tolerance of methanol crossover can be a promising candidate for even other storage and conversion devices. Methods: The physico-chemical properties of the prepared samples were determined by Small Angle X-ray Diffraction (SAXRD), N2 sorption-desorption, Transmission Electron Microscopy (TEM), Field Emission Scanning Electron Microscopy (FESEM) and X-ray Photoelectron Spectroscopy (XPS). The prepared samples were further applied for oxygen reduction reaction (ORR) and the optimal cathode was tested with the Microbial Fuel Cell (MFC) system. Furthermore, according to structural analysis, The HRTEM, and SAXRD results confirmed the formation of well-ordered hexagonal (p6mm) arrays of mesopores in the direction of (100). The EDS and XPS approved that N and S were successfully doped into the CMK-3 carbon framework. Results: Among all the studied CMK-3 based catalysts, the catalyst prepared by STP precursor and pyrolysis at 900°C exhibited the highest ORR activity with the onset potential of 1.02 V vs. RHE and 4 electron transfer number per oxygen molecule in 0.1 M KOH. The high catalyst durability and fuel-crossover tolerance led to stable performance of the optimal cathode after 5000 s operation, while the Pt/C cathode-based was considerably degraded. Finally, the MFC system with the optimal cathode displayed 43.9 mW·m-2 peak power density showing even reasonable performance in comparison to a Pt/C 20 wt.%.cathode. Conclusions: The results revealed that the synergistic effect of nitrogen and sulfur co-doped on the carbon substrate structure leads to improvement in catalytic activity. Also, it was clearly observed that the porous structure and order level of the carbon substrate could considerably change the ORR performance.

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