Pt–Co@Pt Octahedral Nanocrystals: Enhancing Their Activity and Durability toward Oxygen Reduction with an Intermetallic Core and an Ultrathin Shell

2021 ◽  
Author(s):  
Minghao Xie ◽  
Zhiheng Lyu ◽  
Ruhui Chen ◽  
Min Shen ◽  
Zhenming Cao ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Octahedral Nanocrystals

Size and Composition Dependence of Oxygen Reduction Reaction Catalytic Activities of Mo-Doped PtNi/C Octahedral Nanocrystals

ACS Catalysis ◽  
2021 ◽  
Vol 11 (18) ◽  
pp. 11407-11415
Author(s):  
Shlomi Polani ◽  
Katherine E. MacArthur ◽  
Malte Klingenhof ◽  
Xingli Wang ◽  
Paul Paciok ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Composition Dependence ◽  
Reduction Reaction ◽  
Catalytic Activities ◽  
Octahedral Nanocrystals

Pt–Co truncated octahedral nanocrystals: a class of highly active and durable catalysts toward oxygen reduction

Nanoscale ◽  
2020 ◽  
Vol 12 (21) ◽  
pp. 11718-11727 ◽  
Author(s):  
Min Shen ◽  
Minghao Xie ◽  
John Slack ◽  
Krysta Waldrop ◽  
Zitao Chen ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Highly Active ◽  
Octahedral Nanocrystals

Pt–Co truncated octahedral nanocrystals were synthesized and evaluated as a class of highly active and durable catalysts toward oxygen reduction.

Size dependent oxygen reduction and methanol oxidation reactions: catalytic activities of PtCu octahedral nanocrystals

2020 ◽  
Vol 10 (16) ◽  
pp. 5501-5512
Author(s):  
Shlomi Polani ◽  
Meital Shviro ◽  
Victor Shokhen ◽  
Melina Zysler ◽  
Andreas Glüsen ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Methanol Oxidation ◽  
Oxidation Reaction ◽  
Reduction Reaction ◽  
Methanol Oxidation Reaction ◽  
Oxidation Reactions ◽  
Co Stripping ◽  
Catalytic Activities ◽  
Size Dependent ◽  
Octahedral Nanocrystals

Synthesis of PtCu octahedral nanocatalysts with controlled size and strain exhibit excellent oxygen reduction reaction, but leads to higher onset over-potentials in methanol oxidation reaction and CO-stripping.

Rational prediction of multifunctional bilayer single atom catalysts for the hydrogen evolution, oxygen evolution and oxygen reduction reactions

Nanoscale ◽  
2020 ◽  
Vol 12 (39) ◽  
pp. 20413-20424
Author(s):  
Riming Hu ◽  
Yongcheng Li ◽  
Fuhe Wang ◽  
Jiaxiang Shang
Keyword(s):  
Oxygen Reduction ◽  
Hydrogen Evolution ◽  
Oxygen Evolution ◽  
Single Atom ◽  
Reduction Reactions ◽  
Oxygen Reduction Reactions

Bilayer single atom catalysts can serve as promising multifunctional electrocatalysts for the HER, ORR, and OER.

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>

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