Synthesis of Cytochrome-like Copper/Sulfur/Graphite Hybrid as a Cathode Catalyst for Oxygen Reduction with High Selective Four-electron Pathway in Alkaline Medium

2020 ◽  
Vol 42 (4) ◽  
pp. 612-612
Author(s):  
Zhaleh Ashtari Zhaleh Ashtari ◽  
Behnam Seyyedi Behnam Seyyedi ◽  
Baharak Sehatnia Baharak Sehatnia
Keyword(s):  
Oxygen Reduction ◽  
Alkaline Medium ◽  
Active Sites ◽  
Copper Phthalocyanine ◽  
Linear Sweep Voltammetry ◽  
Rotating Disk ◽  
Catalytic Performance ◽  
Rotating Disk Electrode ◽  
Hydrogen Electrode ◽  
Wide Range

The cytochrome-like Copper/Sulfur/Graphite electrocatalyst (Cu-S-G) was successfully produced via a facile low temperature process with an impressive performance for oxygen reduction reaction (ORR). The incorporation of trace amounts of copper atoms (andlt; 4%) in the form of copper phthalocyanine (CuPc) noticeably enhanced activity of Sulfur/Graphite (S-G) composite for ORR. The catalytic performance was evaluated by cyclic voltammetry (CV) and linear sweep voltammetry (LSV) methods on a rotating-disk electrode (RDE) in alkaline medium (ΔE = 0.00 to 1.20V vs. Reversible Hydrogen Electrode: RHE). The novel copper-based catalyst was shown superior efficiency compared to platinum base electrocatalyst (Pt0.2/C0.8). The number of electrons consumed (n) per O2 in Cu-S-G was found to vary between 3.87 and 3.90 at a wide range of low overpotentials, which indicates an efficient four-electron pathway from O2 to H2O. Also, the estimated Tafel slopes demonstrate insignificant amount of copper oxide in the surface of electrocatalyst. The Cu-S-G exhibits superior electroactivity durability (ΔE1/2 = -21 mV after 10,000 cycles). We believe that the rather high ORR activity (n ≈ 4 and EOnset=1.06 V vs. RHE) is governed by a unique bio-inspired structure and novel active sites formed upon the anchoring of copper atoms onto the S-G structure.

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.

scholarly journals Electrochemical Reduction of Oxygen Using a Metal–Organic Complex of Cu2+

Proceedings ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 33
Author(s):  
Carla M. Ormachea ◽  
José L. Fernández ◽  
Pedro M. E. Mancini ◽  
María N. Kneeteman
Keyword(s):  
Linear Sweep Voltammetry ◽  
Rotating Disk ◽  
Reduction Reaction ◽  
Rotating Disk Electrode ◽  
Cyclic Voltammogram ◽  
Hydrogen Electrode ◽  
Metal Organic Complex ◽  
Naoh Solution ◽  
Metal Organic ◽  
Electron Transfer Processes

A biphenyl-based copper complex was evaluated as electrocatalyst for the oxygen reduction reaction (orr), for a possible application as cathode material in fuel cells. To carry out this evaluation, the complex was supported on Vulcan carbon and deposited as a film on a glassy carbon rotating disk electrode by drop-casting a 1-μL drop of a suspension of carbon in a solution of the complex in dimethyl sulfoxide containing Nafion as ionic conductive binder, and drying under vacuum. The cyclic voltammogram in 0.1 M NaOH solution showed voltammetric peaks between 0.8 and 1.0 V vs. reference hydrogen electrode, which suggest the existence of electron transfer processes from/toward the ligand. The orr was tested in oxygen-saturated (1 atm) solution by linear sweep voltammetry, which showed significant orr current at relatively low overpotential (around −0.4 V), demonstrating the ability of the complex to electrocatalyze the orr efficiently.

Synthesis, characterization and electrocatalytic properties of bimetallic sulfides CoS/MnS/N-C for oxygen reduction in alkaline media

2021 ◽  
Vol 25 (04) ◽  
pp. 336-342
Author(s):  
Ningchao Liu ◽  
Laihai Huang ◽  
Jian Rong ◽  
Zhaoli Xue ◽  
Zhongping Ou ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Rotating Disk ◽  
Catalytic Performance ◽  
Reduction Reaction ◽  
Rotating Disk Electrode ◽  
Alkaline Media ◽  
Alkaline Condition ◽  
Zeolitic Imidazolate Framework ◽  
Electrocatalytic Properties ◽  
Bimetallic Sulfide

Synthesis, characterization and oxygen reduction reaction (ORR) catalytic properties of bimetallic sulfides CoS/MnS/N-C catalyst was discussed. The catalyst was derived from a typical Co based zeolitic imidazolate framework (ZIF-67) and manganese aminoporphyrin. 5,15-Bis(4-aminophenyl)-10,20-bis(4-bromophenyl) porphyrin manganese oxoacetate loaded with ZIF-67 forms a porphyrin loaded ZIF-67. This product was then calcined at 800ˆ∘C and vulcanized with thioacetamide to obtain the bimetallic sulfide product CoS/MnS/N-C. The structure of CoS/MnS/N-C was further characterized by XRD, XPS, FESEM and HRTEM spectra which indicated a novel porous and hollow sphere structure. The electrocatalytic properties of the bimetallic material as well as its parent porphyrin and ZIF-67 were also compared in alkaline condition (0.1 M KOH) with a rotating disk electrode. The prepared catalyst CoS/MnS/N-C exhibits a higher catalytic performance than its precursors (PorMnOAc, ZIF-67 and PorMnOAc loaded ZIF-67) with almost four electron transfers under this condition.

scholarly journals Hydrogen Oxidation and Oxygen Reduction Reactions on an OsRu-Based Electrocatalyst Synthesized by Microwave Irradiation

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5692
Author(s):  
Ángela Selva-Ochoa ◽  
Javier Su-Gallegos ◽  
P. J. Sebastian ◽  
Lorena Magallón-Cacho ◽  
Edgar Borja-Arco
Keyword(s):  
Fuel Cells ◽  
Microwave Irradiation ◽  
Oxygen Reduction ◽  
Direct Methanol Fuel Cells ◽  
Hydrogen Oxidation ◽  
Linear Sweep Voltammetry ◽  
Rotating Disk ◽  
Rotating Disk Electrode ◽  
Reduction Reactions ◽  
Oxygen Reduction Reactions

This work presents an OsRu-based electrocatalyst synthesis, by a rapid and efficient method through microwave irradiation. The outstanding electrocatalyst shows a dual catalytic activity, demonstrating both hydrogen oxidation and oxygen reduction reactions. The material is structural and morphologically characterized by FT-IR, X-ray diffraction, EDS, and SEM, indicating nanoparticulated Os and Ru metallic phases with a crystallite size of ∼6 nm, calculated by the Scherrer equation. The metal nanoparticles are apparently deposited on a carbonaceous sponge-like morphology structure. Its electrochemical characterization is performed in 0.5 M H2SO4 by the rotating disk electrode technique, employing cyclic and linear sweep voltammetry. Two different ink treatments have been studied to improve the obtained polarization curves. The material was also tested in the presence of methanol for the oxygen reduction reaction, showing an important resistance to this contaminant, making it viable for its use in direct methanol fuel cells (DMFCs) as a cathode and in polymer electrolyte fuel cells (PEMFCs) as an anode as much as a cathode.

Catalytic Activity of Tetranitro-Copper Phthalocyanine Supported on Carbon Nanotubes towards Oxygen Reduction Reaction

2013 ◽  
Vol 706-708 ◽  
pp. 15-19 ◽  
Author(s):  
Feng Ying Chen ◽  
Ke Zhi Li ◽  
He Jun Li
Keyword(s):  
Catalytic Activity ◽  
Oxygen Reduction ◽  
Copper Phthalocyanine ◽  
Solid Phase ◽  
Synthesis Method ◽  
Rotating Disk ◽  
Reduction Reaction ◽  
Rotating Disk Electrode ◽  
Multiwalled Carbon ◽  
Phase Synthesis

Acid-functionalized multiwalled carbon nanotube (AF-MWCNT)-supported tetranitro-copper phthalocyanine (TNCuPc) assemblies were prepared by solid phase synthesis method. The products were characterized by infrared spectroscopy, scanning electron microscopy and XRD. The electrocatalytic activity of the obtained AF-MWCNT-supported TNCuPc assemblies was measured by cyclic voltammetry (CV) and rotating disk electrode (RDE) techniques in an oxygen-saturated 0.1 M KOH. The results showed that the catalytic activity of TNCuPc/AF-MWCNTs towards oxygen reduction was a two-step, two-electron process for oxygen reduction.

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.

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.

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.

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