Electrochemical behavior of a number of bispyridyl-substituted porphyrins and their electrocatalytic activity in molecular oxygen reduction reaction

2016 ◽  
Vol 20 (05) ◽  
pp. 615-623 ◽  
Author(s):  
Minh N. Do ◽  
Nadezhda M. Berezina ◽  
Mikhail I. Bazanov ◽  
Sabir S. Gyseinov ◽  
Mikhail M. Berezin ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Molecular Oxygen ◽  
Electrocatalytic Activity ◽  
Reduction Reaction ◽  
Central Metal ◽  
Axial Ligands ◽  
Active Layers ◽  
Half Wave ◽  
Electrochemical Parameters

The investigation of electrochemical properties of active layers containing 5,15-bis(pyrid-3-yl)-3,7,13,17-tetramethyl-2,8,12,18-tetraethylporphine, [5,15-bis(pyrid-3-yl)-3,7,13,17-tetramethyl-2,8,12, 18-tetraethylporphinato]cobalt(II), bispyridine[5,15-bis(pyrid-3-yl)-3,7,13,17-tetramethyl-2,8,12,18-tetraethylporphinato]cobalt(III), [5,15-bis(pyrid-4-yl)-3,7,13,17-tetramethyl-2,8,12,18-tetraethylporphinato]cobalt(II) and bispyridine[5,15-bis(pyrid-4-yl)-3,7,13,17-tetramethyl-2,8,12,18-tetraethylporphinato]cobalt(III) in 0.1 M KOH aqueous solution has been carried out by cyclic voltammetry. The potential ranges of redox processes related to the transformation of the porphyrin macrocycle, pyridyl substituents and central metal have been established. The electrochemical parameters of oxygen electroreduction reaction (the half-wave potential — E[Formula: see text](O[Formula: see text]), the maximum potential — E[Formula: see text](O[Formula: see text]), the current density — j, the activation energy — Eact) have been determined. It was shown that all porphyrins exhibit the catalytic activity. The electroreduction process of oxygen on electrode with the porphyrin-ligand occurs via 2-electron mechanism to give hydrogen peroxide ion HO2-, and on ones with the cobalt porphyrins — via parallel-sequential pathway including 2-electron and 4-electron processes to give HO2-, OH-. The presence of pyridine axial ligands in Co-complexes leads to a significant increase of the electrocatalytic activity in molecular oxygen reduction reaction.

scholarly journals (Photo)electrocatalysis of molecular oxygen reduction by S-doped graphene decorated with a star-shaped oligothiophene

Nanoscale ◽  
2019 ◽  
Vol 11 (15) ◽  
pp. 7335-7346 ◽  
Author(s):  
Anastasios Stergiou ◽  
Dimitris K. Perivoliotis ◽  
Nikos Tagmatarchis
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Molecular Oxygen ◽  
Electrocatalytic Activity ◽  
Reduction Reaction ◽  
Doped Graphene

The high (photo)electrocatalytic activity and stability towards the oxygen reduction reaction of a star-shaped oligothiophene/S-doped graphene ensemble is presented.

Building Pyridinium Molecular Wires as Axial Ligands for Tuning the Electrocatalytic Activity of Iron Phthalocyanines for the Oxygen Reduction Reaction

ACS Catalysis ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 8406-8419 ◽  
Author(s):  
Ana Pizarro ◽  
Gabriel Abarca ◽  
Cristian Gutiérrez-Cerón ◽  
Diego Cortés-Arriagada ◽  
Fabiano Bernardi ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Electrocatalytic Activity ◽  
Molecular Wires ◽  
Reduction Reaction ◽  
Axial Ligands

scholarly journals Electrocatalysis for Oxygen Reduction Reaction on EDTAFeNa and Melamine co-Derived Self-Supported Fe-N-C Materials

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 623
Author(s):  
Mengfan Shen ◽  
Ziwei Meng ◽  
Tong Xue ◽  
Hongfang Shen ◽  
Xiang-Hui Yan
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Large Scale ◽  
Acid Leaching ◽  
Reduction Reaction ◽  
Scale Production ◽  
Final Annealing ◽  
High Performing ◽  
Half Wave ◽  
Mesoscopic Structure

To explore high-performing alternatives to platinum-based catalysts is highly desirable for lowering costs and thus promoting fuel cell commercialization. Herein, self-supported Fe-N-C materials were prepared by the pyrolysis of dual precursors including EDTA ferric sodium (EDTAFeNa) and melamine (MA), followed by acid-leaching and final annealing. Towards an oxygen reduction reaction (ORR) in 0.1 M KOH, the as-prepared MA/EDTAFeNa-HT2 delivered onset (Eonset) and half-wave (E1/2) potentials of 0.97 and 0.84 V vs. RHE, respectively, identical with that of a state-of-the-art Pt/C catalyst, accompanied with predominantly a four-electron pathway. The introduction of MA and extension of acid-leaching promoted a positive shift of 50 mV for E1/2 relative to that of only the EDTAFeNa-derived counterpart. It was revealed that the enhancement of ORR activity is attributed to a decrease in magnetic Fe species and increase in pyridinic/quanternary nitrogen content whilst nearly excluding effects of the graphitization degree, variety of crystalline iron species, and mesoscopic structure. The usage of dual precursors exhibited great potential for the large-scale production of inexpensive and efficient Fe-N-C materials.

Engineering Mn Atomic Sites in Multi-Dimensional Nitrogen-Doped Carbon for Highly Efficient Oxygen Reduction Reaction

2022 ◽  
Author(s):  
Huixin Ma ◽  
Daijie Deng ◽  
Honghui Zhang ◽  
Feng Chen ◽  
Junchao Qian ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Reduction Reaction ◽  
Single Atom ◽  
Two Dimensional ◽  
One Dimensional ◽  
Nitrogen Doped ◽  
Half Wave ◽  
Nitrogen Doped Carbon

Nitrogen-coordinated single-atom manganese in multi-dimensional nitrogen-doped carbon electrocatalysts (Mn-NC) was successful constructed by combing two-dimensional nanosheets and one-dimensional nanofibers. The Mn-NC exhibited excellent oxygen reduction reaction catalytic activity with half-wave...

Tailoring molecular architectures of Fe phthalocyanine on nanocarbon supports for high oxygen reduction performance

2015 ◽  
Vol 3 (18) ◽  
pp. 10013-10019 ◽  
Author(s):  
Shiming Zhang ◽  
Heyou Zhang ◽  
Xing Hua ◽  
Shengli Chen
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Alkaline Solution ◽  
Electrocatalytic Activity ◽  
Reduction Reaction ◽  
High Oxygen ◽  
Molecular Architectures

Tailored molecular architectures of FePc on nanocarbon supports from nanorods to uniform shells exhibit excellent electrocatalytic activity for the oxygen reduction reaction in alkaline solution.

scholarly journals Modified Carbon Nanotubes: Surface Properties and Activity in Oxygen Reduction Reaction

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1354
Author(s):  
Vera Bogdanovskaya ◽  
Inna Vernigor ◽  
Marina Radina ◽  
Vladimir Sobolev ◽  
Vladimir Andreev ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Zeta Potential ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Surface Area ◽  
Surface Properties ◽  
Reduction Reaction ◽  
Wave Potential ◽  
Half Wave Potential ◽  
Half Wave

In order to develop highly efficient and stable catalysts for oxygen reduction reaction (ORR) that do not contain precious metals, it is necessary to modify carbon nanotubes (CNT) and define the effect of the modification on their activity in the ORR. In this work, the modification of CNTs included functionalization by treatment in NaOH or HNO3 (soft and hard conditions, respectively) and subsequent doping with nitrogen (melamine was used as a precursor). The main parameters that determine the efficiency of modified CNT in ORR are composition and surface area (XPS, BET), hydrophilic–hydrophobic surface properties (method of standard contact porosimetry (MSP)) and zeta potential (dynamic light scattering method). The activity of CNT in ORR was assessed following half-wave potential, current density within kinetic potential range and the electrochemically active surface area (SEAS). The obtained results show that the modification of CNT with oxygen-containing groups leads to an increase in hydrophilicity and, consequently, SEAS, as well as the total (overall) current. Subsequent doping with nitrogen ensures further increase in SEAS, higher zeta potential and specific activity in ORR, reflected in the shift of the half-wave potential by 150 mV for CNTNaOH-N and 110 mV for CNTHNO3-N relative to CNTNaOH and CNTHNO3, respectively. Moreover, the introduction of N into the structure of CNTHNO3 increases their corrosion stability.

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