Nitrogen-Doped Superporous Activated Carbons as Electrocatalysts for the Oxygen Reduction Reaction

Nitrogen-containing superporous activated carbons were prepared by chemical polymerization of aniline and nitrogen functionalization by organic routes. The resulting N-doped carbon materials were carbonized at high temperatures (600–800 °C) in inert atmosphere. X-ray Photoelectron Spectroscopy (XPS) revealed that nitrogen amount ranges from 1 to 4 at.% and the nature of the nitrogen groups depends on the treatment temperature. All samples were assessed as electrocatalysts for the oxygen reduction reaction (ORR) in alkaline solution (0.1 M KOH) in order to understand the role of well-developed microporosity as well as the different nitrogen functionalities on the electrocatalytic performance in ORR. It was observed that nitrogen groups generated at high temperatures were highly selective towards the water formation. Among the investigated samples, polyaniline-derived activated carbon carbonized at 800 °C displayed the best performance (onset potential of 0.88 V versus RHE and an electron transfer number of 3.4), which was attributed to the highest concentration of N–C–O sites.

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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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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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Beyond Nitrogen in the Oxygen Reduction Reaction on Nitrogen-Doped Carbons: A NEXAFS Investigation

Nanomaterials ◽

10.3390/nano11051198 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1198

Author(s):

Eugenia Tanasa ◽

Florentina Iuliana Maxim ◽

Tugce Erniyazov ◽

Matei-Tom Iacob ◽

Tomáš Skála ◽

...

Keyword(s):

Synchrotron Radiation ◽

Oxygen Reduction Reaction ◽

Crystallite Size ◽

Oxygen Reduction ◽

Photoelectron Spectroscopy ◽

Nitrogen Concentration ◽

Nitrogen Plasma ◽

Reduction Reaction ◽

Onset Potential ◽

Nitrogen Doped

Polymer electrolyte membrane fuel cells require cheap and active electrocatalysts to drive the oxygen reduction reaction. Nitrogen-doped carbons have been extensively studied regarding their oxygen reduction reaction. The work at hand looks beyond the nitrogen chemistry and brings to light the role of oxygen. Nitrogen-doped nanocarbons were obtained by a radio-frequency plasma route at 0, 100, 250, and 350 W. The lateral size of the graphitic domain, determined from Raman spectroscopy, showed that the nitrogen plasma treatment decreased the crystallite size. Synchrotron radiation photoelectron spectroscopy showed a similar nitrogen chemistry, albeit the nitrogen concentration increased with the plasma power. Lateral crystallite size and several nitrogen moieties were plotted against the onset potential determined from oxygen reduction reaction curves. There was no correlation between the electrochemical activity and the sample structure, as determine from Raman and synchrotron radiation photoelectron spectroscopy. Near-edge X-ray absorption fine structure (NEXAFS) was performed to unravel the carbon and nitrogen local structure. A difference analysis of the NEXAFS spectra showed that the oxygen surrounding the pyridinic nitrogen was critical in achieving high onset potentials. The work shows that there were more factors at play, other than carbon organization and nitrogen chemistry.

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Highly effective Fe-N-C electrocatalysts toward oxygen reduction reaction originated from 2,6-diaminopyridine

10.21203/rs.3.rs-269575/v1 ◽

2021 ◽

Author(s):

Weixiang Yang ◽

Shuihua Tang ◽

Qiankuan Huang ◽

Qian Zhang ◽

Zhen Tang ◽

...

Keyword(s):

Catalytic Activity ◽

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

Photoelectron Spectroscopy ◽

Active Sites ◽

Cost Effective ◽

Reduction Reaction ◽

Limiting Current ◽

X Ray ◽

Onset Potential

Abstract Fe-N-C electrocatalysts have been intensively studied due to their extraordinary catalytic activity toward oxygen reduction reaction (ORR). Here we prepare a Fe-N-C electrocatalyst through cost-effective and nontoxic precursors of 2,6-diaminopyridine (DAP) and FeCl3, where iron ions react with DAP to formed Fe-Nx species first, followed by polymerization and pyrolysis. X-ray diffraction patterns display no obvious Fe2O3 peaks observed in the catalyst as the nominal content of iron addition is less than 10 wt%. X-ray photoelectron spectroscopy spectra indicate that the catalyst has rich pyridinic nitrogen, graphitic nitrogen and Fe-Nx species, which are considered as active sites for ORR. Therefore the catalyst demonstrates an excellent catalytic activity with an onset potential of about 0.96 V, half-wave potential of about 0.84 V, and a limiting current density of 5.8 mA cm-2, better than commercial Pt/C catalyst in an alkaline medium. Furthermore its stability is also much more excellent than that of Pt/C. This work provides a strategy to synthesize universal M-N-C catalysts.

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Superior FexN electrocatalyst derived from 1,1′-diacetylferrocene for oxygen reduction reaction in alkaline and acidic media

Nanotechnology Reviews ◽

10.1515/ntrev-2020-0057 ◽

2020 ◽

Vol 9 (1) ◽

pp. 843-852

Author(s):

Hunan Jiang ◽

Jinyang Li ◽

Mengni Liang ◽

Hanpeng Deng ◽

Zuowan Zhou

Keyword(s):

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

Current Density ◽

Active Sites ◽

Reduction Reaction ◽

Alkaline Media ◽

Acidic Media ◽

Onset Potential ◽

Acidic And Alkaline Media ◽

The Stability

AbstractAlthough Fe–N/C catalysts have received increasing attention in recent years for oxygen reduction reaction (ORR), it is still challenging to precisely control the active sites during the preparation. Herein, we report FexN@RGO catalysts with the size of 2–6 nm derived from the pyrolysis of graphene oxide and 1,1′-diacetylferrocene as C and Fe precursors under the NH3/Ar atmosphere as N source. The 1,1′-diacetylferrocene transforms to Fe3O4 at 600°C and transforms to Fe3N and Fe2N at 700°C and 800°C, respectively. The as-prepared FexN@RGO catalysts exhibited superior electrocatalytic activities in acidic and alkaline media compared with the commercial 10% Pt/C, in terms of electrochemical surface area, onset potential, half-wave potential, number of electrons transferred, kinetic current density, and exchange current density. In addition, the stability of FGN-8 also outperformed commercial 10% Pt/C after 10000 cycles, which demonstrates the as-prepared FexN@RGO as durable and active ORR catalysts in acidic media.

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Methanol-Tolerant Oxygen Reduction Reaction at Pt–Pd/C Alloy Nanocatalysts

Journal of Fuel Cell Science and Technology ◽

10.1115/1.4001759 ◽

2010 ◽

Vol 8 (1) ◽

Cited By ~ 9

Author(s):

A. Mary Remona ◽

K. L. N. Phani

Keyword(s):

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

Rotating Disk ◽

Reduction Reaction ◽

Rotating Disk Electrode ◽

Methanol Tolerance ◽

Pd Catalysts ◽

Onset Potential ◽

Direct Methanol ◽

Methanol Tolerant

Carbon-supported platinum and Pt–Pd alloy electrocatalysts with different Pt/Pd atomic ratios were synthesized by a microemulsion method at room temperature (metal loading is 10 wt %). The Pt–Pd/C bimetallic catalysts showed a single-phase fcc structure and the mean particle size of Pt–Pd/C catalysts was found to be lower than that of Pt/C. The methanol-tolerant studies of the catalysts were carried out by activity evaluation of oxygen reduction reaction (ORR) on Pt–Pd catalysts using a rotating disk electrode (RDE). The studies indicated that the order of methanol tolerance was found to be PtPd3/C>PtPd/C>Pt3Pd/C. The oxygen reduction activities of all Pt–Pd/C were considerably larger than that of Pt/C with respect to onset and overpotential values. The Pd-loaded catalysts shift the onset potential of ORR by 125 mVMSE, 53 mVMSE, and 41 mVMSE to less cathodic potentials for Pt3Pd/C, PtPd/C, and PtPd3/C, respectively, with reference to Pt/C and the Pt3Pd/C catalyst showed greater shift in the onset value than the other PtPd catalysts reported in literature. Moreover, the Pt–Pd/C catalysts exhibited much higher methanol tolerance during ORR than the Pt/C, assessing that these catalysts may function as a methanol-tolerant cathode catalysts in a direct methanol fuel cell.

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Methanol tolerant, high performance, noble metal free electrocatalyst developed from polyaniline and ferric chloride for the oxygen reduction reaction

RSC Advances ◽

10.1039/c5ra17548h ◽

2015 ◽

Vol 5 (112) ◽

pp. 92648-92655 ◽

Cited By ~ 12

Author(s):

Sankararao Mutyala ◽

Jayaraman Mathiyarasu ◽

Ashok Mulchandani

Keyword(s):

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

Noble Metal ◽

Ferric Chloride ◽

High Performance ◽

Low Cost ◽

Inert Atmosphere ◽

Reduction Reaction ◽

Metal Free ◽

Methanol Tolerant

Here, we report a low-cost, noble metal free Fe–N–C catalyst prepared using carbonized polyaniline (PANI) and ferric chloride as precursors in an inert atmosphere for oxygen reduction reaction.

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

Materials ◽

10.3390/ma13204551 ◽

2020 ◽

Vol 13 (20) ◽

pp. 4551 ◽

Cited By ~ 1

Author(s):

Linglei Jin ◽

Baikang Zhu ◽

Xuesong Wang ◽

Le Zhang ◽

Debin Song ◽

...

Keyword(s):

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

Amorphous Carbon ◽

Photoelectron Spectroscopy ◽

Potassium Hydroxide Solution ◽

Reduction Reaction ◽

Alkaline Media ◽

X Ray ◽

Synthesis Strategy ◽

Fe Nanoparticles

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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