scholarly journals Oxygen reduction reaction mechanism and kinetics on M-NxCy and M@N-C active sites present in model M-N-C catalysts under alkaline and acidic conditions

2019 ◽  
Author(s):  
Ricardo Sgarbi ◽  
Kavita Kumar ◽  
Frédéric Jaouen ◽  
Andrea Zitolo ◽  
Edson A. Ticianelli ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Active Sites ◽  
Reduction Reaction ◽  
Acidic Conditions ◽  
Mechanism And Kinetics

Dissociative Oxygen Reduction Reaction Mechanism on the Neighboring Active Sites of a Boron-Doped Pyrolyzed Fe–N–C Catalyst

2020 ◽  
Vol 124 (21) ◽  
pp. 11383-11391
Author(s):  
Adhitya Gandaryus Saputro ◽  
Apresio Kefin Fajrial ◽  
Arifin Luthfi Maulana ◽  
Fadjar Fathurrahman ◽  
Mohammad Kemal Agusta ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Active Sites ◽  
Reduction Reaction ◽  
Boron Doped

g-C3N4 templated synthesis of the Fe3C@NSC electrocatalyst enriched with Fe–Nx active sites for efficient oxygen reduction reaction

2019 ◽  
Vol 7 (28) ◽  
pp. 16920-16936 ◽  
Author(s):  
Ahmed A. Eissa ◽  
Shaik Gouse Peera ◽  
Nam Hoon Kim ◽  
Joong Hee Lee
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Noble Metal ◽  
Active Sites ◽  
Reduction Reaction ◽  
One Pot ◽  
Templated Synthesis ◽  
Metal Free ◽  
Acidic Conditions ◽  
Template Free

A noble metal-free electrocatalyst for an efficient oxygen reduction reaction under both alkaline and acidic conditions has been fabricated by a one-pot template-free strategy.

scholarly journals A DFT Study of the Oxygen Reduction Reaction Mechanism on Be Doped Graphene

2021 ◽  
Author(s):  
Caroline Kwawu ◽  
Albert Aniagyei ◽  
Destiny Konadu ◽  
Kenneth Limbey ◽  
Richard Tia ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Active Sites ◽  
Density Functional ◽  
High Surface ◽  
High Surface Area ◽  
Dft Method ◽  
Reduction Reaction ◽  
Doped Graphene

Abstract Graphene despite its high surface area has very limited activity towards the oxygen reduction reaction (ORR), demonstrating selectivity towards the unfavorable two-electron mechanism. We have employed the spin polarized density functional theory (DFT) method to investigate the effect of the heteroatom p-type beryllium (Be) dopant on the oxygen reduction reaction activity of graphene. The preferred doping sites, active sites and reaction mechanism available on the doped graphene surfaces were investigated with increasing Be concentrations of 0.03 ML, 0.06 ML and 0.09 ML. Our results reveal that oxygen does not bind strongly to bare graphene, and Be at the lattice sites provides site for the oxygen adsorption and ORR. Oxygen binds dissociatively on the doped surfaces preferentially in the order 0.06 ML > 0.09 ML > 0.03 ML. From this studies introduction of Be impurities in a single honeycomb ring of graphene has significant impact on the binding and adsorbate-adsorbent interactions which leads to dissociative adsorption of oxygen, favouring the 4e- ORR pathway. The reaction is kinetically favoured most on the surface with a stronger O* binding and weaker OH* binding. Overall, the 0.03 ML and 0.06 ML doped surfaces are the most active facets for the ORR showing exergonic reaction energies at 0 V.

Active Sites for Oxygen Reduction Reaction and the Reaction Mechanism in Carbon-Supported Hafnium Oxynitride

2012 ◽  
Vol 1 (1) ◽  
pp. F4-F8 ◽  
Author(s):  
M. Chisaka ◽  
Y. Suzuki ◽  
T. Iijima ◽  
Y. Ishihara ◽  
R. Inada ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Active Sites ◽  
Reduction Reaction ◽  
Hafnium Oxynitride

Nitrogen and sulphur co-doped crumbled graphene for the oxygen reduction reaction with improved activity and stability in acidic medium

2016 ◽  
Vol 4 (16) ◽  
pp. 6014-6020 ◽  
Author(s):  
Siddheshwar N. Bhange ◽  
Sreekuttan M. Unni ◽  
Sreekumar Kurungot
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Acidic Medium ◽  
Active Sites ◽  
Reduction Reaction ◽  
Acidic Conditions ◽  
Co Doped

A crumbled graphene structure with heteroatom doped active sites derived through the pyrolysis of polyethylenedioxythiophene served as an efficient platinum-free electrocatalyst for oxygen reduction under acidic conditions.

scholarly journals Degradation and regeneration of Fe-Nx active sites for oxygen reduction reaction: the role of surface oxidation, Fe demetallation and local carbon microporosity

2021 ◽  
Author(s):  
Dongsheng Xia ◽  
Chenchen Yu ◽  
Yinghao Zhao ◽  
Yinping Wei ◽  
Haiyan Wu ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Active Sites ◽  
Proton Exchange Membrane ◽  
Degradation Mechanism ◽  
Surface Oxidation ◽  
Reduction Reaction ◽  
Proton Exchange ◽  
Exchange Membrane

The severe degradation of Fe-N-C electrocatalysts during long-term oxygen reduction reaction (ORR) has become a major obstacle for application in proton-exchange membrane fuel cells. Understanding the degradation mechanism and regeneration...

scholarly journals Superior FexN electrocatalyst derived from 1,1′-diacetylferrocene for oxygen reduction reaction in alkaline and acidic media

2020 ◽  
Vol 9 (1) ◽  
pp. 843-852
Author(s):  
Hunan Jiang ◽  
Jinyang Li ◽  
Mengni Liang ◽  
Hanpeng Deng ◽  
Zuowan Zhou
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Current Density ◽  
Active Sites ◽  
Reduction Reaction ◽  
Alkaline Media ◽  
Acidic Media ◽  
Onset Potential ◽  
Acidic And Alkaline Media ◽  
The Stability

AbstractAlthough Fe–N/C catalysts have received increasing attention in recent years for oxygen reduction reaction (ORR), it is still challenging to precisely control the active sites during the preparation. Herein, we report FexN@RGO catalysts with the size of 2–6 nm derived from the pyrolysis of graphene oxide and 1,1′-diacetylferrocene as C and Fe precursors under the NH3/Ar atmosphere as N source. The 1,1′-diacetylferrocene transforms to Fe3O4 at 600°C and transforms to Fe3N and Fe2N at 700°C and 800°C, respectively. The as-prepared FexN@RGO catalysts exhibited superior electrocatalytic activities in acidic and alkaline media compared with the commercial 10% Pt/C, in terms of electrochemical surface area, onset potential, half-wave potential, number of electrons transferred, kinetic current density, and exchange current density. In addition, the stability of FGN-8 also outperformed commercial 10% Pt/C after 10000 cycles, which demonstrates the as-prepared FexN@RGO as durable and active ORR catalysts in acidic media.

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