Facile Synthesis of the Amorphous Carbon Coated Fe-N-C Nanocatalyst with Efficient Activity for Oxygen Reduction Reaction in Acidic and Alkaline Media

With the assistance of surfactant, Fe nanoparticles are supported on g-C3N4 nanosheets by a simple one-step calcination strategy. Meanwhile, a layer of amorphous carbon is coated on the surface of Fe nanoparticles during calcination. Transmission electron microscopy (TEM), scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma (ICP) were used to characterize the morphology, structure, and composition of the catalysts. By electrochemical evaluate methods, such as linear sweep voltammetry (LSV) and cyclic voltammetry (CV), it can be found that Fe25-N-C-800 (calcinated in 800 °C, Fe loading content is 5.35 wt.%) exhibits excellent oxygen reduction reaction (ORR) activity and selectivity. In 0.1 M KOH (potassium hydroxide solution), compared with the 20 wt.% Pt/C, Fe25-N-C-800 performs larger onset potential (0.925 V versus the reversible hydrogen electrode (RHE)) and half-wave potential (0.864 V vs. RHE) and limits current density (2.90 mA cm−2, at 400 rpm). In 0.1 M HClO4, it also exhibits comparable activity. Furthermore, the Fe25-N-C-800 displays more excellent stability and methanol tolerance than Pt/C. Therefore, due to convenience synthesis strategy and excellent catalytic activity, the Fe25-N-C-800 will adapt to a suitable candidate for non-noble metal ORR catalyst in fuel cells.

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Ethanol: Tolerant Oxygen Reduction Reaction Catalysts in Alkaline Media

Journal of Electrochemical Energy Conversion and Storage ◽

10.1115/1.4041979 ◽

2018 ◽

Vol 16 (2) ◽

Cited By ~ 1

Author(s):

Chakkrapong Chaiburi ◽

Bernd Cermenek ◽

Birgit Elvira Pichler ◽

Christoph Grimmer ◽

Viktor Hacker

Keyword(s):

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

State Of The Art ◽

Rotating Disk ◽

Reduction Reaction ◽

Rotating Disk Electrode ◽

Alkaline Media ◽

Direct Ethanol Fuel Cells ◽

X Ray ◽

Transmission Electron

This paper describes electrocatalysts for the oxygen reduction reaction (ORR) in alkaline direct ethanol fuel cells (ADEFCs), using the non-noble metal electrocatalyst Ag/C, MnO2/C and AgMnO2/C. These electrocatalysts showed tolerance toward ethanol in alkaline media and therefore resistance to ethanol crossover in ADEFCs. Transmission electron microscopy, X-ray spectroscopy (EDX), cyclic voltammetry, and rotating disk electrode (RDE) were employed to determine the morphology, composition, and electrochemical activity of the catalysts. The herein presented results confirm that the AgMnO2/C electrocatalyst significantly outperforms the state-of-the art ORR catalyst platinum.

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MOF-Derived CuPt/NC Electrocatalyst for Oxygen Reduction Reaction

Catalysts ◽

10.3390/catal10070799 ◽

2020 ◽

Vol 10 (7) ◽

pp. 799 ◽

Cited By ~ 1

Author(s):

Rehan Anwar ◽

Naseem Iqbal ◽

Saadia Hanif ◽

Tayyaba Noor ◽

Xuan Shi ◽

...

Keyword(s):

Electron Microscopy ◽

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

Photoelectron Spectroscopy ◽

Rotating Disk ◽

Reduction Reaction ◽

Rotating Disk Electrode ◽

X Ray ◽

Onset Potential ◽

Orr Activity

Metal-organic frameworks (MOFs) have been at the center stage of material science in the recent past because of their structural properties and wide applications in catalysis. MOFs have also been used as hard templates for the preparation of catalysts. In this study, highly active CuPt/NC electrocatalyst was synthesized by pyrolyzing Cu-tpa MOF along with Pt precursor under flowing Ar-H2 atmosphere. The catalyst was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray powder diffraction (XRD). Rotating disk electrode study was performed to determine the oxygen reduction reaction (ORR) activity for CuPt/NC in 0.1 M HClO4 at different revolutions per minute (400, 800, 1200, and 1600) and it was also compared with commercial Pt/C catalyst. Further the ORR performance was evaluated by K-L plots and Tafel slope. CuPt/NC shows excellent ORR performance with onset potential of 0.9 V (vs. RHE), which is comparable with commercial Pt/C. The ORR activity of CuPt/NC is demonstrated as an efficient electrocatalyst for fuel cell.

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Metallic Organic Framework-Derived Fe, N, S co-doped Carbon as a Robust Catalyst for the Oxygen Reduction Reaction in Microbial Fuel Cells

Energies ◽

10.3390/en12203846 ◽

2019 ◽

Vol 12 (20) ◽

pp. 3846 ◽

Cited By ~ 1

Author(s):

Xiao Luo ◽

Wuli Han ◽

Han Ren ◽

Qingzuo Zhuang

Keyword(s):

Fuel Cells ◽

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

Microbial Fuel Cells ◽

Active Sites ◽

Reduction Reaction ◽

Alkaline Media ◽

X Ray ◽

Co Doped ◽

Organic Framework

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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Co3O4 Nanoparticles-Modified α-MnO2 Nanorods Supported on Reduced Graphene Oxide as Cathode Catalyst for Oxygen Reduction Reaction in Alkaline Media

NANO ◽

10.1142/s1793292016501265 ◽

2016 ◽

Vol 11 (11) ◽

pp. 1650126 ◽

Cited By ~ 16

Author(s):

GuanHua Jin ◽

Suqin Liu ◽

Yaomin Li ◽

Yang Guo ◽

Zhiying Ding

Keyword(s):

Electron Microscopy ◽

Graphene Oxide ◽

Catalytic Activity ◽

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

Reduced Graphene Oxide ◽

Reduction Reaction ◽

Alkaline Media ◽

X Ray ◽

Reduced Graphene

Development of efficient electrocatalysts for the oxygen reduction reaction (ORR) remains a key issue for the commercialization of metal-air batteries. In this study, the novel structured Co3O4 nanoparticles-modified [Formula: see text]-MnO2 nanorods supported on reduced graphene oxide (Co3O4-MnO2/rGO) were synthesized with varying amounts of [Formula: see text]-MnO2 via a facile two-step hydrothermal method. The relationship between the physical properties and the electrochemical results was investigated using X-ray diffraction spectrum, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, cyclic voltammograms, electrochemical impedance spectroscopy and rotating disk electrode. The as-prepared Co3O4–MnO2 nanohybrid exhibits enhanced catalytic activity for ORR under alkaline condition compared with MnO2/rGO and Co3O4/rGO. Furthermore, it mainly favors a direct 4e-reaction pathway for ORR, which is attributed to the well-designed structure, the synergistic effect between Co3O4 and [Formula: see text]-MnO2, and the covalent coupling between the Co3O4-MnO2 and reduced graphene oxide. The role of Co3O4 in Co3O4–MnO2 hybrid for catalyzing ORR also has been illustrated by varying the mass ratio of Co3O4 and MnO2, which reveals that the Co3O4–MnO2 with the ratio of 1:1 has better catalytic activity.

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High impact of the reducing agent on palladium nanomaterials: new insights from X-ray photoelectron spectroscopy and oxygen reduction reaction

RSC Advances ◽

10.1039/c5ra24829a ◽

2016 ◽

Vol 6 (15) ◽

pp. 12627-12637 ◽

Cited By ~ 26

Author(s):

Yaovi Holade ◽

Christine Canaff ◽

Suzie Poulin ◽

Têko W. Napporn ◽

Karine Servat ◽

...

Keyword(s):

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

Chemical Stability ◽

Photoelectron Spectroscopy ◽

Reduction Reaction ◽

High Impact ◽

Reducing Agent ◽

X Ray ◽

Catalytic Performances

The nature of the reduction agent changes drastically the palladium nanomaterials chemical stability, which subsequently alters earnestly their catalytic performances.

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PtNi and CoNi Film Electrocatalysts Prepared by MOCVD for the Oxygen Reduction Reaction in Alkaline Media

Journal of New Materials for Electrochemical Systems ◽

10.14447/jnmes.v14i2.114 ◽

2011 ◽

Vol 14 (2) ◽

pp. 81-85 ◽

Cited By ~ 1

Author(s):

M. A. Garcia-Contreras ◽

S. M. Fernandez-Valverde ◽

J. R. Vargas-Garcia

Keyword(s):

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

Chemical Vapour ◽

Rotating Disk ◽

Reduction Reaction ◽

Rotating Disk Electrode ◽

Alkaline Media ◽

Organic Chemical ◽

Experimental Conditions ◽

X Ray

CoNi and PtNi film electrocatalysts were prepared by Metal-Organic Chemical Vapour Deposition (MOCVD) and their electrocatalytic activity for the oxygen reduction reaction (ORR) in 0.5 M KOH was investigated by cyclic voltammetry and Rotating Disk Electrode techniques. Experiments included working electrodes of Co, Ni and Pt prepared also by MOCVD for comparison. The film electrocatalysts were characterized by X-ray diffraction, Scanning Electronic Microscopy and Energy dispersive X-ray analysis. Films thickness was about 200-250 nm and nanocrystallites were found in the range of 12 to 30 nm. In the same experimental conditions, the overpotential for the ORR at a current density of 1 mA cm-2 for PtNi film was 120 mV lower than the overpotential of Pt film electrocatalyst, and an enhanced activity was observed on PtNi with respect to Pt. The electrochemical response for the oxygen reduction reaction on CoNi film was higher than those of elemental Ni and Co films obtained by MOCVD. A good stability was obtained in a chronoamperometry test for the PtNi electrode, only affected by oxygen flow variations.

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Non-precious Melamine/Chitosan Composites for the Oxygen Reduction Reaction: Effect of the Transition Metal

Frontiers in Materials ◽

10.3389/fmats.2020.578518 ◽

2020 ◽

Vol 7 ◽

Author(s):

B. Aghabarari ◽

M. V. Martínez-Huerta ◽

M. C. Capel-Sánchez ◽

M. J. Lázaro

Keyword(s):

Transition Metal ◽

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

Photoelectron Spectroscopy ◽

Low Cost ◽

Reduction Reaction ◽

X Ray ◽

Transmission Electron ◽

Electrode Cell ◽

C And N

The development of active and low-cost electrocatalysts for the oxygen reduction reaction (ORR) is crucial for the sustainable commercialization of fuel cell technologies. In this study, we have synthetized Me/Mo2C (Me = Fe, Co, Cu)-based composites embedded in N- and P-dual doped carbon by means of inexpensive industrial materials, such as melamine and chitosan, as C and N sources, and the heteropolyacid H3PMo12O40 as P and Mo precursor. The effect of the transition metal (Fe, Co, and Cu) on the ORR in alkaline medium has been investigated. The physicochemical properties of the electrocatalysts were performed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and transmission electron microscopy (TEM). Activity towards ORR was carried out in a three-electrode cell using a ring-disk electrode in 0.1M NaOH. The results obtained clearly show the important role played by each transition metal (Fe, Co, and Cu) in the electrochemical activity. Among them, Fe gives rise to the best performing composite in carrying out the oxygen reduction reaction. The formation Fe3C/Mo2C species embedded in N- and P-dual doped carbon seems to be the determining role in the increase of the ORR performance.

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Electrocatalytic Performance of Carbon Supported WO3-Contained Pd-W Nanoalloys for Oxygen Reduction Reaction in Alkaline Media

10.20944/preprints201804.0097.v1 ◽

2018 ◽

Author(s):

Nan Cui ◽

Zengfeng Guo ◽

Wenpeng Li ◽

Xun Xu ◽

Hongxia Zhao ◽

...

Keyword(s):

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

Photoelectron Spectroscopy ◽

Reduction Reaction ◽

Alkaline Media ◽

Alkaline Electrolyte ◽

Atom Ratio ◽

Onset Potential ◽

Electrocatalytic Performance ◽

Catalytic Stability

In this paper, we first report that WOx contained nanoalloys exhibit stable electrocatalytic performance in alkaline media, though bulk WO3 are easy to be dissolved in NaOH solutions. Carbon supported oxide-rich Pd-W alloy nanoparticles (PdW/C) with different Pd:W atom ratios were prepared by reduction-oxidation method. Among the catalysts, the oxide-rich Pd0.8W0.2/C (Pd/W = 8:2, atom ratio) exhibits the highest catalytic activity for oxygen reduction reaction. The X-ray photoelectron spectroscopy data shows that ~40% of Pd atoms and ~60% of the W atoms are in their oxides form. The Pd 3d5/2 peaks in oxide-rich Pd-W nanoalloys are positive shift compared with that of Pd/C, which indicates the electronic structure of Pd is affected by the strong interaction between Pd and W/WO3. Compare to Pd/C, the onset potential of oxygen reduction reaction at the oxide-rich Pd0.8W0.2/C is positive shifted. The current density (mA·mg Pd−1) at the oxide-rich Pd0.8W0.2/C is ~1.6 times of that at Pd/C. The oxide-rich Pd0.8W0.2/C also exhibits higher catalytic stability than Pd/C, which demonstrate that it is a prospective candidate for the cathode of fuel cells operated with alkaline electrolyte.

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