Creation of oxygen reduction reaction active sites on titanium oxynitride without increasing the nitrogen doping level

2018 ◽  
Vol 20 (23) ◽  
pp. 15613-15617 ◽  
Author(s):  
Mitsuharu Chisaka
Keyword(s):  
Low Temperature ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Doping Level ◽  
Active Sites ◽  
Nitrogen Doping ◽  
Reduction Reaction ◽  
Low Temperature Annealing

Active sites were created on ORR-active titanium oxynitride by low-temperature annealing without changing the nitrogen doping level to determine their origin.

scholarly journals Proposal of a Facile Method to Fabricate a Multi-Dope Multiwall Carbon Nanotube as a Metal-Free Electrocatalyst for the Oxygen Reduction Reaction

2022 ◽  
Vol 14 (2) ◽  
pp. 965
Author(s):  
Sara Bakhtavar ◽  
Mehdi Mehrpooya ◽  
Mahboobeh Manoochehri ◽  
Mehrnoosh Karimkhani
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Electron Transfer ◽  
Low Temperature ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Active Sites ◽  
Reduction Reaction ◽  
Multiwall Carbon Nanotube ◽  
Multiwall Carbon

In this study, a one-pot, low-temperature synthesis method is considered for the fabrication of heteroatom dope multiwall carbon nanotubes (MWCNT). Doped MWCNT is utilized as an effective electrocatalyst for oxygen reduction reaction (ORR). Single, double, and triple doping of boron, nitrogen and sulfur elements are utilized as the dopants. A reflux system with temperature of 180 °C is implemented in the doping procedure. Actually, unlike the previous studies in which doping on the carbon structures was performed using a furnace at temperatures above 700 °C, in this green and sustainable method, the triple doping on MWCNT is conducted at atmospheric pressure and low temperature. The morphology and structure of the fabricated catalysts were evaluated by Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and Raman spectroscopy. According to the results, the nanoparticles were encapsulated in the carbon nanotubes. Aggregated clusters of the sulfur in the case of S-MWCNT are considerable. Cyclic voltammetry (CV), rotating disk electrode, linear sweep voltammetry (LSV), and chronoamperometry electrochemical tests are employed for assessing the oxygen reduction activity of the catalysts. The results illustrate that by using this doping method, the onset potential shifts to positive values towards the oxidized MWCNT. It can be deduced that by doping the N, B, and S atoms on MWCNTs, the defects in the CNT structure, which serve as active sites for ORR application, increase. The N/S/B-doped graphitic layers have a more rapid electron transfer rate at the electrode/electrolyte interface. Thus, this can improve the electrochemistry performance and electron transfer of the MWCNTs. The best performance and electrochemical activity belonged to the NB-MWCNT catalyst (−0.122 V vs. Ag/AgCl). Also, based on the results gained from the Koutecky–Levich (KL) plot, it can be said that the ORR takes place through the 4 e− pathway.

N-Doping of graphene oxide at low temperature for the oxygen reduction reaction

2017 ◽  
Vol 53 (5) ◽  
pp. 873-876 ◽  
Author(s):  
Hengcong Tao ◽  
Chao Yan ◽  
Alex W. Robertson ◽  
Yunnan Gao ◽  
Jingjing Ding ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Low Temperature ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Nitrogen Doping ◽  
Ammonia Solution ◽  
Reduction Reaction ◽  
N Doping ◽  
First Time

Nitrogen doping of graphene oxide was demonstrated for the first time at 5 °C in ammonia solution via ultrasonication.

Boosting graphene electrocatalytic efficiency in oxygen reduction reaction by mechanochemically induced low-temperature nitrogen doping

2021 ◽  
pp. 139410
Author(s):  
Oleg Yu Posudievsky ◽  
Andrey S. Kondratyuk ◽  
Olga A. Kozarenko ◽  
Vsevolod V. Cherepanov ◽  
Volodymyr L. Karbivskiy ◽  
...  
Keyword(s):  
Low Temperature ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Nitrogen Doping ◽  
Reduction Reaction

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.

Fe ultra-small particles anchored on carbon aerogels to enhance the oxygen reduction reaction in Zn-air batteries

2021 ◽  
Author(s):  
Jinjin Shi ◽  
Xinxin Shu ◽  
Chensheng Xiang ◽  
Hong Li ◽  
Yang Li ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Active Sites ◽  
Carbon Aerogel ◽  
Reduction Reaction ◽  
Superior Performance ◽  
Carbon Aerogels ◽  
Small Particles

The Fe–N4–O–Fe–N4 moiety as active sites in ultra-small Fe particles anchored on carbon aerogel exhibited superior performance towards the oxygen reduction reaction.

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