Twofold Effects of Zirconium Doping into TiN on Durability and Oxygen Reduction Reactivity in an Acidic Environment

An N-doped graphitic carbon layer was for the first time introduced to greatly enhance the durability of a PtNi3/C alloy catalyst in an acidic environment.

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Dissolution of Oxygen Reduction Electrocatalysts in an Acidic Environment: Density Functional Theory Study

The Journal of Physical Chemistry A ◽

10.1021/jp063447o ◽

2006 ◽

Vol 110 (32) ◽

pp. 9783-9787 ◽

Cited By ~ 49

Author(s):

Zhihui Gu ◽

Perla B. Balbuena

Keyword(s):

Density Functional Theory ◽

Oxygen Reduction ◽

Density Functional ◽

Acidic Environment ◽

Density Functional Theory Study ◽

Functional Theory

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Facile synthesis, spectroscopy and electrochemical activity of two substituted iron phthalocyanines as oxygen reduction catalysts in an acidic environment

Electrochimica Acta ◽

10.1016/j.electacta.2008.12.003 ◽

2009 ◽

Vol 54 (11) ◽

pp. 3098-3102 ◽

Cited By ~ 38

Author(s):

Ryan Baker ◽

David P. Wilkinson ◽

Jiujun Zhang

Keyword(s):

Oxygen Reduction ◽

Electrochemical Activity ◽

Acidic Environment ◽

Facile Synthesis ◽

Oxygen Reduction Catalysts ◽

Reduction Catalysts

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Nitrogen and sulfur co-doped porous carbon – is an efficient electrocatalyst as platinum or a hoax for oxygen reduction reaction in acidic environment PEM fuel cell?

Energy ◽

10.1016/j.energy.2016.11.066 ◽

2017 ◽

Vol 119 ◽

pp. 1075-1083 ◽

Cited By ~ 22

Author(s):

Madhumita Sahoo ◽

S. Ramaprabhu

Keyword(s):

Fuel Cell ◽

Oxygen Reduction Reaction ◽

Oxygen Reduction ◽

Porous Carbon ◽

Pem Fuel Cell ◽

Reduction Reaction ◽

Acidic Environment ◽

Co Doped

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Strongly Coupled Cobalt Diselenide Monolayers Selectively Catalyze Oxygen Reduction to H2O2 in an Acidic Environment

Angewandte Chemie ◽

10.1002/ange.202111075 ◽

2021 ◽

Author(s):

Min-Rui Gao ◽

Xiao-Long Zhang ◽

Xiaozhi Su ◽

Ya-Rong Zheng ◽

Shao-Jin Hu ◽

...

Keyword(s):

Oxygen Reduction ◽

Acidic Environment ◽

Strongly Coupled

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

Nanoscale ◽

10.1039/d0nr05202g ◽

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.

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Computational Study of Site-Specific Correlations among Oxygen Reduction Intermediates on Pd3Y (111)

Journal of Advanced Catalysis Science and Technology ◽

10.15379/2408-9834.2014.01.02.1 ◽

2014 ◽

Vol 1 (2) ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Masoud Aryanpour ◽

Keyword(s):

Oxygen Reduction ◽

Computational Study ◽

Site Specific

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pH Dependent Release Potential of Natural Polymers in Sustained Release of Ornidazole From Colon Targeted Delivery System)

International Journal of Drug Delivery Technology ◽

10.25258/ijddt.9.2.4 ◽

2019 ◽

Vol 9 (02) ◽

Author(s):

Sharma Pankaj ◽

Tailang Mukul

Keyword(s):

Drug Release ◽

Delivery System ◽

Targeted Delivery ◽

Guar Gum ◽

Acidic Environment ◽

Natural Polymers ◽

Weight Variation ◽

Curve Determination ◽

Preformulation Studies

The aim of present work was to prepare colon specific delivery system of Ornidazole using different ratio of shellac, zein and guar gum. From study of various literature it revealed that shellac, zein and guar gum released drug from dosage form at the pH of 6.9, 11.5, 7-9 respectively. The main problem associated with colon targeted drug delivery system is degradation of drug in the acidic environment of stomach to circumvent the present problem different combinations of shellac, zein and guar gum were employed in the formulation of colon targeted tablet. Several preformulation parameters were determined such as melting point, FTIR spectroscopy, preparation of calibration curve, determination of λmax and partition coefficient. After the preformulation studies, next steps were preparation of core tablets, evaluation of core of tablets and coating of tablets. The data obtained from preformulation study seven formulations were developed and evaluated for various parameters. Based on evaluated parameter such as weight variation, friability, dissolution study, invitro drug release etc. the F7 formulation show better results colon targeted tablets. Drug content in F7 formulation was 95% and drug release after 6 hrs was 96%. Formulation containing combination of shellac, zein and guar gum released least amount of drug in the acidic environment of stomach and released most of the drug in colon. It is evide

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

10.26434/chemrxiv.10008545.v2 ◽

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-N4 pyridinic ligation environment. Yet, molecular Fe-based catalysts for the oxygen reduction reaction (ORR) generally feature pyrrolic coordination and pyridinic Fe-N4 catalysts are, to the best of our knowledge, non-existent. We report the synthesis and characterization of a molecular pyridinic hexaazacyclophane macrocycle, (phen2N2)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 (phen2N2)Fe are positively shifted relative to (Pc)Fe and (OEP)Fe, and overlay with those of Fe-N-C. Likewise, spectroscopic XAS signatures of (phen2N2)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 (phen2N2)Fe that are close to the average 1.94 Å length in Fe-N-C. Electrochemical studies establish that both (Pc)Fe and (phen2N2)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 (phen2N2)Fe relative to (OEP)Fe. Consequently, the ORR onset for (phen2N2)Fe and (Pc)Fe is within 150 mV of Fe-N-C. Unlike (OEP)Fe and (Pc)Fe, (phen2N2)Fe displays excellent selectivity for 4-electron ORR with <4% maximum H2O2 production, comparable to Fe-N-C materials. The aggregate spectroscopic and electrochemical data establish (phen2N2)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.

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