Boosting Electrochemical Oxygen Reduction Performance of Iron Phthalocyanine through Axial Coordination Sphere Interaction

ChemSusChem ◽  
2021 ◽  
Author(s):  
Wenlin Zhang ◽  
Eva J. Meeus ◽  
Lei Wang ◽  
Lu-Hua Zhang ◽  
Shuangcheng Yang ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Coordination Sphere ◽  
Iron Phthalocyanine ◽  
Axial Coordination ◽  
Electrochemical Oxygen

A Pyridinic Fe-N4 Macrocycle Effectively Models the Active Sites in Fe/N-Doped Carbon Electrocatalysts

2020 ◽  
Author(s):  
Travis Marshall-Roth ◽  
Nicole J. Libretto ◽  
Alexandra T. Wrobel ◽  
Kevin Anderton ◽  
Nathan D. Ricke ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Active Sites ◽  
Catalytic Properties ◽  
Reduction Reaction ◽  
Iron Phthalocyanine ◽  
Electrochemical Studies ◽  
Onset Potential ◽  
Nitrogen Doped Carbon ◽  
Iron Active Sites

Iron- and nitrogen-doped carbon (Fe-N-C) materials are leading candidates to replace platinum in fuel cells, but their active site structures are poorly understood. A leading postulate is that iron active sites in this class of materials exist in an Fe-N<sub>4</sub> pyridinic ligation environment. Yet, molecular Fe-based catalysts for the oxygen reduction reaction (ORR) generally feature pyrrolic coordination and pyridinic Fe-N<sub>4</sub> catalysts are, to the best of our knowledge, non-existent. We report the synthesis and characterization of a molecular pyridinic hexaazacyclophane macrocycle, (phen<sub>2</sub>N<sub>2</sub>)Fe, and compare its spectroscopic, electrochemical, and catalytic properties for oxygen reduction to a prototypical Fe-N-C material, as well as iron phthalocyanine, (Pc)Fe, and iron octaethylporphyrin, (OEP)Fe, prototypical pyrrolic iron macrocycles. N 1s XPS signatures for coordinated N atoms in (phen<sub>2</sub>N<sub>2</sub>)Fe are positively shifted relative to (Pc)Fe and (OEP)Fe, and overlay with those of Fe-N-C. Likewise, spectroscopic XAS signatures of (phen<sub>2</sub>N<sub>2</sub>)Fe are distinct from those of both (Pc)Fe and (OEP)Fe, and are remarkably similar to those of Fe-N-C with compressed Fe–N bond lengths of 1.97 Å in (phen<sub>2</sub>N<sub>2</sub>)Fe that are close to the average 1.94 Å length in Fe-N-C. Electrochemical studies establish that both (Pc)Fe and (phen<sub>2</sub>N<sub>2</sub>)Fe have relatively high Fe(III/II) potentials at ~0.6 V, ~300 mV positive of (OEP)Fe. The ORR onset potential is found to directly correlate with the Fe(III/II) potential leading to a ~300 mV positive shift in the onset of ORR for (Pc)Fe and (phen<sub>2</sub>N<sub>2</sub>)Fe relative to (OEP)Fe. Consequently, the ORR onset for (phen<sub>2</sub>N<sub>2</sub>)Fe and (Pc)Fe is within 150 mV of Fe-N-C. Unlike (OEP)Fe and (Pc)Fe, (phen<sub>2</sub>N<sub>2</sub>)Fe displays excellent selectivity for 4-electron ORR with <4% maximum H<sub>2</sub>O<sub>2</sub> production, comparable to Fe-N-C materials. The aggregate spectroscopic and electrochemical data establish (phen<sub>2</sub>N<sub>2</sub>)Fe as a pyridinic iron macrocycle that effectively models Fe-N-C active sites, thereby providing a rich molecular platform for understanding this important class of catalytic materials.<p><b></b></p>

Modulating Catalytic Properties of Targeted Metal Cationic Centers in Nonstochiometric Mixed Metal Oxides for Electrochemical Oxygen Reduction

2021 ◽  
pp. 1065-1072
Author(s):  
Samji Samira ◽  
John Carl A. Camayang ◽  
Krishna Patel ◽  
Xiang-Kui Gu ◽  
Eranda Nikolla
Keyword(s):  
Metal Oxides ◽  
Oxygen Reduction ◽  
Catalytic Properties ◽  
Mixed Metal Oxides ◽  
Mixed Metal ◽  
Electrochemical Oxygen

General Strategy for Synthesis of Pd3 M (M = Co and Ni) Nanoassemblies as High-Performance Catalysts for Electrochemical Oxygen Reduction

2017 ◽  
Vol 5 (3) ◽  
pp. 1701015 ◽  
Author(s):  
Yifan Chen ◽  
Xian Jiang ◽  
Yueyang Li ◽  
Pei Li ◽  
Qicheng Liu ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
High Performance ◽  
General Strategy ◽  
Electrochemical Oxygen

The electrochemical oxygen reduction on the graphite electrode

1983 ◽  
Vol 28 (5) ◽  
pp. 685-690 ◽  
Author(s):  
B. Lovreček ◽  
M. Batinic ◽  
J. Čaja
Keyword(s):  
Oxygen Reduction ◽  
Graphite Electrode ◽  
Electrochemical Oxygen

scholarly journals Electrochemical oxygen reduction catalysed by Ni3(hexaiminotriphenylene)2

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Elise M. Miner ◽  
Tomohiro Fukushima ◽  
Dennis Sheberla ◽  
Lei Sun ◽  
Yogesh Surendranath ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Electrochemical Oxygen

Mechanism of Electrochemical Oxygen Reduction Reaction at Two-Dimensional Pt-doped MoSe2 Material: An Efficient Electrocatalyst

2021 ◽  
Author(s):  
Shrish Nath Upadhyay ◽  
Srimanta Pakhira
Keyword(s):  
Fuel Cells ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Clean Energy ◽  
Reduction Reaction ◽  
Electrochemical Reactions ◽  
Two Dimensional ◽  
O2 Reduction ◽  
Energy Conversion Systems ◽  
Electrochemical Oxygen

The O2 reduction reaction (ORR) is one promising reaction in clean energy conversion systems such as fuel cells, metal-air batteries, electrochemical reactions, etc. Pt shows excellent electrocatalytic activities for ORR,...

Alloy Nanocatalysts for the Electrochemical Oxygen Reduction (ORR) and the Direct Electrochemical Carbon Dioxide Reduction Reaction (CO 2 RR)

2018 ◽  
Vol 31 (31) ◽  
pp. 1805617 ◽  
Author(s):  
Cheonghee Kim ◽  
Fabio Dionigi ◽  
Vera Beermann ◽  
Xingli Wang ◽  
Tim Möller ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Reduction ◽  
Carbon Dioxide Reduction ◽  
Reduction Reaction ◽  
Electrochemical Oxygen
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