Synthesis of Bimetallic AuPt Nanoparticles in Aqueous Solution and Electrocatalytic Activity

2005 ◽  
Vol 900 ◽  
Author(s):  
Peter N. Njoki ◽  
Jin Luo ◽  
Aisley Jacob ◽  
Rizwan Munawar ◽  
Bilal Khan ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Electrocatalytic Activity ◽  
Bimetallic Nanoparticles ◽  
Rotating Disk ◽  
Reduction Reaction ◽  
Rotating Disk Electrode ◽  
Morphological Properties ◽  
Nanoparticle Catalysts ◽  
Bimetallic Nanoparticle

ABSTRACTThe ability to control composition and size in the synthesis of bimetallic nanoparticles is important for the exploitation of the bimetallic catalytic properties. This paper reports recent findings of an investigation of the synthesis of gold-platinum (AuPt) bimetallic nanoparticles in aqueous solution via reduction of AuCl4− and PtCl42− using a combination of reducing and capping agents. In addition to characterization of the morphological properties of the AuPt nanoparticles using TEM and XRD, the electrocatalytic activity of the carbon-supported AuPt nanoparticle catalysts was also examined for oxygen reduction reaction (ORR) using the rotating disk electrode (RDE) technique. The findings have implications to the design of bimetallic nanoparticle catalysts for fuel cell reactions.

scholarly journals Accurate Assessment of the Oxygen Reduction Electrocatalytic Activity of Mn/Polypyrrole Nanocomposites Based on Rotating Disk Electrode Measurements, Complemented with Multitechnique Structural Characterizations

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Patrizia Bocchetta ◽  
Carolina Ramírez Sánchez ◽  
Antonietta Taurino ◽  
Benedetto Bozzini
Keyword(s):  
Oxygen Reduction ◽  
Electrocatalytic Activity ◽  
Rotating Disk ◽  
Reduction Reaction ◽  
Rotating Disk Electrode ◽  
Activity Measurement ◽  
Disk Electrode ◽  
Atomic Force ◽  
Structural Characterizations

This paper reports on the quantitative assessment of the oxygen reduction reaction (ORR) electrocatalytic activity of electrodeposited Mn/polypyrrole (PPy) nanocomposites for alkaline aqueous solutions, based on the Rotating Disk Electrode (RDE) method and accompanied by structural characterizations relevant to the establishment of structure-function relationships. The characterization of Mn/PPy films is addressed to the following: (i) morphology, as assessed by Field-Emission Scanning Electron Microscopy (FE-SEM) and Atomic Force Microscope (AFM); (ii) local electrical conductivity, as measured by Scanning Probe Microscopy (SPM); and (iii) molecular structure, accessed by Raman Spectroscopy; these data provide the background against which the electrocatalytic activity can be rationalised. For comparison, the properties of Mn/PPy are gauged against those of graphite, PPy, and polycrystalline-Pt (poly-Pt). Due to the literature lack of accepted protocols for precise catalytic activity measurement at poly-Pt electrode in alkaline solution using the RDE methodology, we have also worked on the obtainment of an intralaboratory benchmark by evidencing some of the time-consuming parameters which drastically affect the reliability and repeatability of the measurement.

scholarly journals Synthesis and electrocatalytic activity towards oxygen reduction reaction of gold-nanostars

2018 ◽  
Vol 18 (44) ◽  
pp. 36-40
Author(s):  
Oyunbileg G ◽  
Batnyagt G ◽  
Enkhsaruul B ◽  
T Takeguchi
Keyword(s):  
Electron Microscope ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Electrocatalytic Activity ◽  
Electrical Energy ◽  
Rotating Disk ◽  
Reduction Reaction ◽  
Rotating Disk Electrode ◽  
Alkaline Electrolyte ◽  
Study Results

The oxygen reduction reaction (ORR) is a characteristic reaction which determines the performance of fuel cells which convert a chemical energy into an electrical energy. Aims of this study are to synthesize Au-based nanostars (AuNSs) and determine their preliminary electro-catalytic activities towards ORR by a rotating-disk electrode method in alkaline electrolyte. The images obtained from a scanning electron microscope (SEM) and a transmission electron microscope (TEM) analyses confirm the formation of the star-shaped nanoparticles. Among the investigated nanostar catalysts, an AuNS5 with smaller size and a few branches showed the higher electrocatalytic activity towards ORR than other catalysts with a bigger size. In addition, the electron numbers transferred for all the catalysts are approximately two. The present study results infer that the size of the Au-based nanostars may influence greatly on their catalytic activity. The present study results show that the further improvement is needed for Au-based nanostar catalysts towards the ORR reaction.

Electrochemical Reduction of Nitrous Oxide (N2O) Catalysed by Tetraaminophthalocyanatocobalt(II) Adsorbed on a Graphite Electrode in Aqueous Solution

1997 ◽  
Vol 01 (04) ◽  
pp. 323-331 ◽  
Author(s):  
JIUJUN ZHANG ◽  
YU-HONG TSE ◽  
A. B. P. LEVER ◽  
W. J. PIETRO
Keyword(s):  
Aqueous Solution ◽  
Nitrous Oxide ◽  
Electrochemical Reduction ◽  
Modified Electrode ◽  
Electrocatalytic Activity ◽  
Graphite Electrode ◽  
Rotating Disk ◽  
Rotating Disk Electrode ◽  
Disk Electrode ◽  
Ph Range

The surface electrochemical response of the Co II/ Co I redox process of tetraaminophthalocyaninatocobalt(II) ( Co II TAPc ) adsorbed on a graphite electrode, was studied in the pH range of 2–13. In aqueous solution, the Co II TAPc adsorbed graphite electrode displays very strong electrocatalytic activity toward N 2 O reduction to N 2, a process which was examined by cyclic and rotating disk electrode voltammetries. The possible application of this Co II TAPc modified electrode in N 2 O analysis was explored.

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 Perovskite-Type Oxides La0.6M0.4Ni0.6Cu0.4O3 (M = Ag, Ba, Ce) towards the Oxygen Reduction Reaction (ORR) in Alkaline Medium: Structural Aspects and Electrocatalytic Activity

2021 ◽  
Author(s):  
Alan Lima ◽  
Alex Lima ◽  
Gabriel Meloni ◽  
Carla Santos ◽  
Mauro Bertotti
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Alkaline Medium ◽  
Electrocatalytic Activity ◽  
Pechini Method ◽  
Rotating Disk ◽  
Reduction Reaction ◽  
Rotating Disk Electrode ◽  
Competition Mode ◽  
Good Catalytic Activity

In this work, La0.6M0.4Ni0.6Cu0.4O3 (M = Ag, Ba, and Ce, denoted as LANC, LBNC, and LCNC, respectively) electrocatalysts were synthesized by the Pechini method at 1023 K for two hours in air. Rietveld refinement allowed the identification of the crystallographic phases present in all oxides. The electrocatalytic performance of these oxides towards the oxygen reduction reaction (ORR) was examined in alkaline medium by rotating disk electrode (RDE) technique and scanning electrochemical microscopy (SECM) in the redox competition mode. The results indicate that the best performance was found with the LANC electrocatalyst prepared with carbon as a conducting agent (LANC/Carbon), which showed good catalytic activity towards the ORR via a pseudo fourelectron transfer pathway. The enhanced electrocatalytic activity of LANC is probably a result of the presence of a Ag phase, which improves the synergistic effect between the perovskite and carbon added to increase the conductivity, thus leading to a higher ORR performance when compared to other materials.

Fabrication and Characterization of Nife Thin Film Composition Modulated Alloys

1996 ◽  
Vol 451 ◽  
Author(s):  
S. D. Leith ◽  
D. T. Schwartz
Keyword(s):  
Rotation Rate ◽  
Stripping Voltammetry ◽  
Rotating Disk ◽  
Oscillation Period ◽  
Rotating Disk Electrode ◽  
Disk Rotation ◽  
Rate Oscillation ◽  
Composition And Structure ◽  
Spatially Periodic

ABSTRACTDescribed are results showing that an oscillating flow-field can induce spatially periodic composition variations in electrodeposited NiFe films. Flow-induced NiFe composition modulated alloys (CMA's) were deposited on the disk of a rotating disk electrode by oscillating the disk rotation rate during galvanostatic plating. Deposit composition and structure were investigated using potentiostatic stripping voltammetry and scanning probe microscopy. Results illustrate a linear relationship between the composition modulation wavelength and the flow oscillation period. CMA's with wavelengths less than 10 nm can be fabricated when plating with a disk rotation rate oscillation period less than 3 seconds.

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.

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