The oxygen reduction reaction at the three-phase boundary: nanoelectrodes modified with Ag nanoclusters

2016 ◽  
Vol 193 ◽  
pp. 241-250 ◽  
Author(s):  
Jan Clausmeyer ◽  
Alexander Botz ◽  
Denis Öhl ◽  
Wolfgang Schuhmann

Silver nanoclusters are deposited on bifunctional Θ-shaped nanoelectrodes consisting of a carbon nanoelectrode combined with a hollow nanopipette. The Θ-nanoelectrodes are used as model systems to study interfacial mass transport in gas diffusion electrodes and in particular oxygen-depolarized cathodes (ODC) for the oxygen reduction reaction (ORR) in chlor-alkali electrolysers. By local delivery of O2 gas to the electroactive Ag nanoclusters through the adjacent nanopipette, enhanced currents for the ORR at the Ag nanoparticles are recorded which are not accountable when considering the low solubility and slow diffusion of O2 in highly alkaline media. Instead, local oversaturation of O2 leads to current enhancement at the Ag nanoclusters. Due to the intrinsic high mass transport rates at the nanometric electrodes accompanied by local delivery of reactants, the method generally allows to study electrochemical reactions at single nanoparticles beyond the limitations induced by slow diffusion and low reactant concentration. Kinetic and mechanistic information, for instance derived from Tafel slopes, can be obtained from kinetic regimes not accessible to standard techniques.

2019 ◽  
Vol 7 (44) ◽  
pp. 25557-25566 ◽  
Author(s):  
Min Hong ◽  
Jianhang Nie ◽  
Xiaohua Zhang ◽  
Pengfei Zhang ◽  
Qin Meng ◽  
...  

FeNx atom clusters anchored on N-enriched graphene carbon aerogel exhibited high mass specific activity (840 mA mgFe−1 at 0.80 V), positive E1/2 (0.90 V vs. RHE), excellent durability and strong tolerance to methanol and SCN− in alkaline media.


2020 ◽  
Vol 9 (1) ◽  
pp. 843-852
Author(s):  
Hunan Jiang ◽  
Jinyang Li ◽  
Mengni Liang ◽  
Hanpeng Deng ◽  
Zuowan Zhou

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.


ChemSusChem ◽  
2014 ◽  
Vol 7 (12) ◽  
pp. 3356-3361 ◽  
Author(s):  
Zhiming Cui ◽  
Minghui Yang ◽  
Hao Chen ◽  
Mengtian Zhao ◽  
Francis J. DiSalvo

2019 ◽  
Vol 71 ◽  
pp. 234-241 ◽  
Author(s):  
Yun Sik Kang ◽  
Yoonhye Heo ◽  
Jae Young Jung ◽  
Yeonsun Sohn ◽  
Soo-Hyoung Lee ◽  
...  

RSC Advances ◽  
2015 ◽  
Vol 5 (2) ◽  
pp. 1571-1580 ◽  
Author(s):  
Dongyoon Shin ◽  
Beomgyun Jeong ◽  
Myounghoon Choun ◽  
Joey D. Ocon ◽  
Jaeyoung Lee

An optimal catalyst testing methodology that could allow precise benchmarking to obtain standardized ORR activity is put forward.


Sign in / Sign up

Export Citation Format

Share Document