Emergence of Oxygen Reduction Activity in Zirconium Oxide-Based Compounds in Acidic Media: Creation of Active Sites for the Oxygen Reduction Reaction

2019 ◽  
Vol 123 (30) ◽  
pp. 18150-18159 ◽  
Author(s):  
Akimitsu Ishihara ◽  
Takaaki Nagai ◽  
Keisuke Ukita ◽  
Masazumi Arao ◽  
Masashi Matsumoto ◽  
...  
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.


2019 ◽  
Vol 9 (3) ◽  
pp. 611-619 ◽  
Author(s):  
Mitsuharu Chisaka ◽  
Hiroyuki Morioka

Phosphor and nitrogen atoms were co-doped into rutile TiO2 phase on TiN to produce new active sites for oxygen reduction reaction.


ACS Catalysis ◽  
2016 ◽  
Vol 6 (10) ◽  
pp. 7249-7259 ◽  
Author(s):  
Kuldeep Mamtani ◽  
Deeksha Jain ◽  
Dmitry Zemlyanov ◽  
Gokhan Celik ◽  
Jennifer Luthman ◽  
...  

ACS Catalysis ◽  
2014 ◽  
Vol 4 (10) ◽  
pp. 3454-3462 ◽  
Author(s):  
Deepika Singh ◽  
Kuldeep Mamtani ◽  
Christopher R. Bruening ◽  
Jeffrey T. Miller ◽  
Umit S. Ozkan

2014 ◽  
Vol 2 (8) ◽  
pp. 2663-2670 ◽  
Author(s):  
Ulrike I. Kramm ◽  
Iris Herrmann-Geppert ◽  
Sebastian Fiechter ◽  
Gerald Zehl ◽  
Ivo Zizak ◽  
...  

This work presents two strategies on how the disintegration of FeN4 sites by iron carbide formation can be avoided.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Gege Yang ◽  
Jiawei Zhu ◽  
Pengfei Yuan ◽  
Yongfeng Hu ◽  
Gan Qu ◽  
...  

AbstractAs low-cost electrocatalysts for oxygen reduction reaction applied to fuel cells and metal-air batteries, atomic-dispersed transition metal-nitrogen-carbon materials are emerging, but the genuine mechanism thereof is still arguable. Herein, by rational design and synthesis of dual-metal atomically dispersed Fe,Mn/N-C catalyst as model object, we unravel that the O2 reduction preferentially takes place on FeIII in the FeN4 /C system with intermediate spin state which possesses one eg electron (t2g4eg1) readily penetrating the antibonding π-orbital of oxygen. Both magnetic measurements and theoretical calculation reveal that the adjacent atomically dispersed Mn-N moieties can effectively activate the FeIII sites by both spin-state transition and electronic modulation, rendering the excellent ORR performances of Fe,Mn/N-C in both alkaline and acidic media (halfwave positionals are 0.928 V in 0.1 M KOH, and 0.804 V in 0.1 M HClO4), and good durability, which outperforms and has almost the same activity of commercial Pt/C, respectively. In addition, it presents a superior power density of 160.8 mW cm−2 and long-term durability in reversible zinc–air batteries. The work brings new insight into the oxygen reduction reaction process on the metal-nitrogen-carbon active sites, undoubtedly leading the exploration towards high effective low-cost non-precious catalysts.


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