Mn-Co oxide/PEDOT as a bifunctional electrocatalyst for oxygen evolution/reduction reactions

2015 ◽  
Vol 1777 ◽  
pp. 1-6 ◽  
Author(s):  
Elaheh Davari ◽  
Douglas G. Ivey
Keyword(s):  
Oxygen Reduction ◽  
Oxygen Evolution ◽  
Linear Sweep Voltammetry ◽  
Microstructural Characterization ◽  
Rotating Disk ◽  
Reduction Reaction ◽  
Rotating Disk Electrode ◽  
Bifunctional Electrocatalyst ◽  
Bifunctional Electrocatalysts ◽  
Anodic Electrodeposition

ABSTRACTBifunctional electrocatalysts, which facilitate the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), are vital components in advanced metal-air batteries. Results are presented for carbon-free, nanocrystalline, rod-like, Mn-Co oxide/PEDOT bifunctional electrocatalysts, prepared by template-free sequential anodic electrodeposition. Electrochemical characterization of synthesized electrocatalysts, with and without a conducting polymer (PEDOT) coating, was performed using cyclic voltammetry (CV) and linear sweep voltammetry (LSV). In addition, microstructural characterization was conducted using SEM, TEM, STEM and XPS. Mn-Co oxide/PEDOT showed improved ORR/OER performance relative to Mn-Co oxide and PEDOT. On the basis of rotating disk electrode (RDE) experiments, Mn-Co oxide/PEDOT displayed the desired 4-electron transfer oxygen reduction pathway. Comparable ORR activity and superior OER activity relative to commercial Pt/C were observed.

Preparation of a One-Dimensional Hierarchical MnO@CNT@Co-N/C Ternary Nanostructure as a High-Performance Bifunctional Electrocatalyst for Rechargeable Zn-Air Batteries

2021 ◽  
Author(s):  
Fen Li ◽  
Qin Tengteng ◽  
Yuping Sun ◽  
Renjun Jiang ◽  
Jiangfeng Yuan ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
High Performance ◽  
Reduction Reaction ◽  
One Dimensional ◽  
Bifunctional Electrocatalyst ◽  
Significant Challenge ◽  
Bifunctional Electrocatalysts

Developing high-performance bifunctional electrocatalysts for both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is a significant challenge for the implementation of rechargeable Zn-air batteries. Herein, MnO2 nanotubes...

scholarly journals Spray-Pyrolytic Tunable Structures of Mn Oxides-Based Composites for Electrocatalytic Activity Improvement in Oxygen Reduction

Metals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 22
Author(s):  
Miroslava Varničić ◽  
Miroslav M. Pavlović ◽  
Sanja Eraković Pantović ◽  
Marija Mihailović ◽  
Marijana R. Pantović Pavlović ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Hybrid Materials ◽  
Electrocatalytic Activity ◽  
Ultrasonic Spray Pyrolysis ◽  
Linear Sweep Voltammetry ◽  
Rotating Disk ◽  
Reduction Reaction ◽  
Single Step ◽  
Rotating Disk Electrode ◽  
Alkaline Media

Hybrid nanomaterials based on manganese, cobalt, and lanthanum oxides of different morphology and phase compositions were prepared using a facile single-step ultrasonic spray pyrolysis (USP) process and tested as electrocatalysts for oxygen reduction reaction (ORR). The structural and morphological characterizations were completed by XRD and SEM-EDS. Electrochemical performance was characterized by cyclic voltammetry and linear sweep voltammetry in a rotating disk electrode assembly. All synthesized materials were found electrocatalytically active for ORR in alkaline media. Two different manganese oxide states were incorporated into a Co3O4 matrix, δ-MnO2 at 500 and 600 °C and manganese (II,III) oxide-Mn3O4 at 800 °C. The difference in crystalline structure revealed flower-like nanosheets for birnessite-MnO2 and well-defined spherical nanoparticles for material based on Mn3O4. Electrochemical responses indicate that the ORR mechanism follows a preceding step of MnO2 reduction to MnOOH. The calculated number of electrons exchanged for the hybrid materials demonstrate a four-electron oxygen reduction pathway and high electrocatalytic activity towards ORR. The comparison of molar catalytic activities points out the importance of the composition and that the synergy of Co and Mn is superior to Co3O4/La2O3 and pristine Mn oxide. The results reveal that synthesized hybrid materials are promising electrocatalysts for ORR.

scholarly journals PtCoNb2O5/graphene as electrocatalyst towards oxygen reduction reaction in alkaline and acidic media

Chemija ◽  
2018 ◽  
Vol 29 (1) ◽  
Author(s):  
Virginija Kepenienė ◽  
Raminta Stagniūnaitė ◽  
Loreta Tamašauskaitė-Tamašiūnaitė ◽  
Vidas Pakštas ◽  
Eugenijus Norkus
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Cobalt Catalyst ◽  
Linear Sweep Voltammetry ◽  
Rotating Disk ◽  
Reduction Reaction ◽  
Rotating Disk Electrode ◽  
Acidic Media ◽  
Acidic Solutions ◽  
Supported Platinum

The aim of the study was to prepare and to investigate the catalytic activity of the Nb2O5/graphene-supported platinum–cobalt catalyst for the oxygen reduction reaction (ORR) in alkaline and acidic media. Electrocatalytic properties of the prepared catalyst towards the oxygen reduction reaction were characterized by using cyclic voltammetry (CV) and rotating disk electrode (RDE) linear sweep voltammetry (LSV). It has been found that the PtCoNb2O5/graphene catalyst shows more positive onset potentials, as well as higher current in the mixed-kineticdiffusion region towards the oxygen reduction reaction in both alkaline and acidic solutions as compared with those for the bare Pt/GR catalyst.

Metal molybdate nanorods as non-precious electrocatalysts for the oxygen reduction

2015 ◽  
Vol 08 (03) ◽  
pp. 1540005 ◽  
Author(s):  
Tian Wu ◽  
Lieyu Zhang
Keyword(s):  
Fuel Cells ◽  
Oxygen Reduction ◽  
Large Scale ◽  
Linear Sweep Voltammetry ◽  
Rotating Disk ◽  
Reduction Reaction ◽  
Rotating Disk Electrode ◽  
Alkaline Media ◽  
One Pot ◽  
Metal Molybdate

Development of non-precious electrocatalysts with applicable electrocatalytic activity towards the oxygen reduction reaction (ORR) is important to fulfill broad-based and large-scale applications of metal/air batteries and fuel cells. Herein, nickel and cobalt molybdates with uniform nanorod morphology are synthesized using a facile one-pot hydrothermal method. The ORR activity of the prepared metal molybdate nanorods in alkaline media are investigated by using cyclic voltammetry (CV), linear sweep voltammetry (LSV) and chronoamperomety in rotating disk electrode (RDE) techniques. The present study suggests that the prepared metal molybdate nanorods exhibit applicable electrocatalytic activities towards the ORR in alkaline media, promising the applications as non-precious cathode in fuel cells and metal–air batteries.

scholarly journals Eco-Friendly Nitrogen-Doped Graphene Preparation and Design for the Oxygen Reduction Reaction

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3858
Author(s):  
Monica Dan ◽  
Adriana Vulcu ◽  
Sebastian A. Porav ◽  
Cristian Leostean ◽  
Gheorghe Borodi ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Rotating Disk ◽  
Reduction Reaction ◽  
Machine Learning Algorithms ◽  
Rotating Disk Electrode ◽  
X Ray ◽  
Synthesis Conditions ◽  
Characterization Techniques ◽  
Doped Graphene

Four N-doped graphene materials with a nitrogen content ranging from 8.34 to 13.1 wt.% are prepared by the ball milling method. This method represents an eco-friendly mechanochemical process that can be easily adapted for industrial-scale productivity and allows both the exfoliation of graphite and the synthesis of large quantities of functionalized graphene. These materials are characterized by transmission and scanning electron microscopy, thermogravimetry measurements, X-ray powder diffraction, X-ray photoelectron and Raman spectroscopy, and then, are tested towards the oxygen reduction reaction by cyclic voltammetry and rotating disk electrode methods. Their responses towards ORR are analysed in correlation with their properties and use for the best ORR catalyst identification. However, even though the mechanochemical procedure and the characterization techniques are clean and green methods (i.e., water is the only solvent used for these syntheses and investigations), they are time consuming and, generally, a low number of materials can be prepared, characterized and tested. In order to eliminate some of these limitations, the use of regression learner and reverse engineering methods are proposed for facilitating the optimization of the synthesis conditions and the materials’ design. Thus, the machine learning algorithms are applied to data containing the synthesis parameters, the results obtained from different characterization techniques and the materials response towards ORR to quickly provide predictions that allow the best synthesis conditions or the best electrocatalysts’ identification.

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

2010 ◽  
Vol 8 (1) ◽  
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.

Ethanol: Tolerant Oxygen Reduction Reaction Catalysts in Alkaline Media

2018 ◽  
Vol 16 (2) ◽  
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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