The Mechanism of Dioxygen Reduction at Iron meso-Tetrakis (Pyridyl) Porphyrin: a Spectroelectrochemical Study

1998 ◽  
Vol 02 (03) ◽  
pp. 249-260 ◽  
Author(s):  
S. POPOVICI ◽  
W. LEYFFER ◽  
R. HOLZE
Keyword(s):  
Hydrogen Peroxide ◽  
Cyclic Voltammetry ◽  
Strong Influence ◽  
Resonance Raman ◽  
Reduction Reaction ◽  
Reduction Product ◽  
Dioxygen Reduction ◽  
Primary Reduction

The mechanism of the dioxygen interaction with and reduction reaction at iron α,β,γ,δ-tetra(4-pyridyl) porphyrin ( FeTPyP ) deposited on carbon and silver supporting electrodes was investigated with cyclic voltammetry and FTIR, UV-vis and resonance Raman spectroscopies. Results indicate a strong influence of the ligand upon the reduction electrocatalysis. Spectroelectrochemical results support a two-electron pathway resulting most probably in hydrogen peroxide as the primary reduction product.

On the Mechanism of Dioxygen Electroreduction at Transition Metal meso-Tetrakis Pyridyl Porphyrins—a Comparative Spectroelectrochemical Study

1999 ◽  
Vol 03 (04) ◽  
pp. 265-282 ◽  
Author(s):  
S. POPOVICI ◽  
W. LEYFFER ◽  
R. HOLZE
Keyword(s):  
Transition Metal ◽  
Metal Ion ◽  
Strong Influence ◽  
Resonance Raman Spectroscopy ◽  
Reduction Reaction ◽  
Central Metal ◽  
Dioxygen Reduction ◽  
Vis Spectroscopy ◽  
Primary Reduction ◽  
Pyridyl Porphyrins

The mode of interaction with and the mechanism of the dioxygen reduction reaction at six transition metal α,β,γ,δ-tetra(4-pyridyl)porphyrins (MeTPyPs) deposited on carbon and silver supporting electrodes were investigated with cyclic voltammetry, FTIR and UV-vis spectroscopy and resonance Raman spectroscopy. Results indicate a strong influence of both the ligand and the central metal ion upon the reduction electrocatalysis in terms of electrode overpotentials. Spectroelectrochemical results support a two-electron pathway resulting in hydrogen peroxide as the primary reduction product. A significant influence of the central ion on the vibrational behaviour and the dioxygen reduction mechanism was not found.

Electrocatalytic Studies of Oxygen Reduction by Lanthanum Barium Manganate

2006 ◽  
Vol 258-260 ◽  
pp. 327-332 ◽  
Author(s):  
Diogo M.F. Santos ◽  
César A.C. Sequeira
Keyword(s):  
Hydrogen Peroxide ◽  
Cyclic Voltammetry ◽  
Oxygen Reduction ◽  
Oxide Catalyst ◽  
Reduction Reaction ◽  
Disc Electrode ◽  
Dissociative Chemisorption ◽  
Electroreduction Of Oxygen ◽  
Rotating Ring Disc Electrode ◽  
Electrode Technique

The electrocatalysis of the oxygen reduction reaction by Lanthanum Barium Manganate, (La0.5Ba0.5MnO3) (LBM) has been studied by cyclic voltammetry using the rotating ring-disc electrode technique (RRDE) in alkaline medium. From the ring-disc data and other kinetic parameters it has been assumed that the oxygen reduction occurs by dissociative chemisorption at low overpotentials. At higher overpotentials, the formation of hydrogen peroxide (HO2 - in this case) has been observed on this electrocatalyst. The apparent exchange current density value for oxygen reduction on LBM has been found to be 4 x 10-8 Acm-2, while the corresponding Tafel slope is 0.115 V per decade. The possible reaction mechanism for electroreduction of oxygen on this oxide catalyst has been discussed.

Study on the Electrochemical Behavior of Ferric Stearate and its Electro-Catalytic Oxidation of Hydrogen Peroxide

2009 ◽  
Vol 610-613 ◽  
pp. 161-164
Author(s):  
Li Li Liang ◽  
Xue Gang Luo ◽  
Xiao Yan Lin
Keyword(s):  
Hydrogen Peroxide ◽  
Cyclic Voltammetry ◽  
Catalytic Oxidation ◽  
Tin Oxide ◽  
Electrochemical Behavior ◽  
Doctor Blade ◽  
Conductive Glass ◽  
Oxidation Of Hydrogen ◽  
Electro Catalytic Oxidation ◽  
Catalytic Effects

A ferric stearate electrode was made by doctor-blade methods using the Fluorine tin oxide (FTO) conductive glass. The electrochemical behavior of ferric stearate electrode was studied by the cyclic voltammetry. The electro-catalytic effects of ferric stearate on H2O2 were also investigated by cyclic voltammetry.

A Two-step Electrodeposition of Pd-Cu/Cu2O Nanocomposite on FTO Substrate for Non-enzymatic Hydrogen Peroxide Sensor

2021 ◽  
Vol 17 ◽  
Author(s):  
Ke Huan ◽  
Li Tang ◽  
Dongmei Deng ◽  
Huan Wang ◽  
Xiaojing Si ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Cyclic Voltammetry ◽  
Photoelectron Spectroscopy ◽  
Chemical Structure ◽  
Pd Nanoparticles ◽  
Optimal Conditions ◽  
Potential Oscillation ◽  
X Ray Diffraction ◽  
X Ray

Background: Hydrogen peroxide (H2O2) is a common reagent in the production and living, but excessive H2O2 may enhance the danger to the human body. Consequently, it is very important to develop economical, fast and accurate techniques for detecting H2O2. Methods: A simple two-step electrodeposition process was applied to synthesize Pd-Cu/Cu2O nanocomposite for non-enzymatic H2O2 sensor. Cu/Cu2O nanomaterial was firstly electrodeposited on FTO by potential oscillation technique, and then Pd nanoparticles were electrodeposited on Cu/Cu2O nanomaterial by cyclic voltammetry. The chemical structure, component, and morphology of the synthesized Pd-Cu/Cu2O nanocomposite were characterized by X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. The electrochemical properties of Pd-Cu/Cu2O nanocomposite were studied by cyclic voltammetry and amperometry. Results: Under optimal conditions, the as-fabricated sensor displayed a broad linear range (5-4000 µM) and low detection limit (1.8 µM) for the determination of H2O2. The proposed sensor showed good selectivity and reproducibility. Meanwhile, the proposed sensor has been successfully applied to detect H2O2 in milk. Conclusion: The Pd-Cu/Cu2O/FTO biosensor exhibits excellent electrochemical activity for H2O2 reduction, which has great potential application in the field of food safety.

scholarly journals Effect of pH on the Electrochemical Behavior of Hydrogen Peroxide in the Presence of Pseudomonas aeruginosa

2021 ◽  
Vol 9 ◽  
Author(s):  
Javier Espinoza-Vergara ◽  
Paulo Molina ◽  
Mariana Walter ◽  
Miguel Gulppi ◽  
Nelson Vejar ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Pseudomonas Aeruginosa ◽  
Enzymatic Activity ◽  
Electrochemical Behavior ◽  
Electrochemical Techniques ◽  
Stable State ◽  
Reduction Reaction ◽  
Maximum Activity ◽  
Open Circuit ◽  
Mueller Hinton

The influence of pH on the electrochemical behavior of hydrogen peroxide in the presence of Pseudomonas aeruginosa was investigated using electrochemical techniques. Cyclic and square wave voltammetry were used to monitor the enzymatic activity. A modified cobalt phthalocyanine (CoPc) carbon electrode (OPG), a known catalyst for reducing O2 to H2O2, was used to detect species resulting from the enzyme activity. The electrolyte was a sterilized aqueous medium containing Mueller-Hinton (MH) broth. The open-circuit potential (OCP) of the Pseudomonas aeruginosa culture in MH decreased rapidly with time, reaching a stable state after 4 h. Peculiarities in the E / I response were observed in voltammograms conducted in less than 4 h of exposure to the culture medium. Such particular E/I responses are due to the catalase’s enzymatic action related to the conversion of hydrogen peroxide to oxygen, confirming the authors’ previous findings related to the behavior of other catalase-positive microorganisms. The enzymatic activity exhibits maximum activity at pH 7.5, assessed by the potential at which oxygen is reduced to hydrogen peroxide. At higher or lower pHs, the oxygen reduction reaction (ORR) occurs at higher overpotentials, i.e., at more negative potentials. In addition, and to assess the influence of bacterial adhesion on the electrochemical behavior, measurements of the bacterial-substrate metal interaction were performed at different pH using atomic force microscopy.

Efficient hydrogen peroxide synthesis by metal-free polyterthiophene via photoelectrocatalytic dioxygen reduction

2020 ◽  
Vol 13 (1) ◽  
pp. 238-245 ◽  
Author(s):  
Wenjun Fan ◽  
Bingqing Zhang ◽  
Xiaoyu Wang ◽  
Weiguang Ma ◽  
Deng Li ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Oxygen Reduction ◽  
Cost Effective ◽  
High Concentration ◽  
Metal Free ◽  
Dioxygen Reduction ◽  
Polymeric Semiconductor ◽  
Hydrogen Peroxide Synthesis

We demonstrate the metal-free polymeric semiconductor pTTh as a selective and efficient photocathode for photoelectrochemical oxygen reduction to a high concentration of H2O2 in a cost-effective way.

Reactivity descriptors for Cu bis-phenanthroline catalysts for the hydrogen peroxide reduction reaction

2020 ◽  
Vol 357 ◽  
pp. 136881
Author(s):  
Karina Muñoz-Becerra ◽  
Daniela F. Báez ◽  
José H. Zagal ◽  
Soledad Bollo ◽  
Alejandro Toro-Labbé ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Reduction Reaction ◽  
Reactivity Descriptors ◽  
Peroxide Reduction ◽  
Hydrogen Peroxide Reduction ◽  
Hydrogen Peroxide Reduction Reaction
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