scholarly journals Density functional theory calculations on the CO catalytic oxidation on Al-embedded graphene

RSC Advances ◽  
2014 ◽  
Vol 4 (39) ◽  
pp. 20290-20296 ◽  
Author(s):  
Q. G. Jiang ◽  
Z. M. Ao ◽  
S. Li ◽  
Z. Wen
Keyword(s):  
Density Functional Theory ◽  
Co Oxidation ◽  
Energy Barrier ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Co Catalytic Oxidation ◽  
Rate Limiting

The energy barrier of the CO oxidation for the rate limiting step on Al-embedded graphene is only 0.32 eV.

scholarly journals Mechanism of Guaiacol Hydrodeoxygenation on Cu (111): Insights from Density Functional Theory Studies

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 523
Author(s):  
Destiny Konadu ◽  
Caroline Rosemyya Kwawu ◽  
Richard Tia ◽  
Evans Adei ◽  
Nora Henriette de Leeuw
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Reaction Path ◽  
Binding Energies ◽  
Functional Theory ◽  
Thermodynamics And Kinetics ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
The Density Functional Theory ◽  
Rate Limiting

Understanding the mechanism of the catalytic upgrade of bio-oils via the process of hydrodeoxygenation (HDO) is desirable to produce targeted oxygen-deficient bio-fuels. We have used calculations based on the density functional theory to investigate the reaction mechanism of HDO of guaiacol over Cu (111) surface in the presence of H2, leading to the formation of catechol and anisole. Our analysis of the thermodynamics and kinetics involved in the reaction process shows that catechol is produced via direct demethylation, followed by dehydrogenation of –OH and re-hydrogenation of catecholate in a concerted fashion. The de-methylation step is found to be the rate-limiting step for catechol production with a barrier of 1.97 eV. Formation of anisole will also proceed via the direct dehydroxylation of guaiacol followed by hydrogenation. Here, the rate-limiting step is the dehydroxylation step with an energy barrier of 2.07 eV. Thermodynamically, catechol formation is favored while anisole formation is not favored due to the weaker interaction seen between anisole and the Cu (111) surface, where the binding energies of guaiacol, catechol, and anisole are -1.90 eV, −2.18 eV, and −0.72 eV, respectively. The stepwise barriers also show that the Cu (111) surface favors catechol formation over anisole as the rate-limiting barrier is higher for anisole production. For catechol, the overall reaction is downhill, implying that this reaction path is thermodynamically and kinetically preferred and that anisole, if formed, will more easily transform.

scholarly journals Pd/Pt embedded CN monolayers as efficient catalysts for CO oxidation

2019 ◽  
Vol 21 (46) ◽  
pp. 25743-25748
Author(s):  
Yong-Chao Rao ◽  
Xiang-Mei Duan
Keyword(s):  
Density Functional Theory ◽  
Co Oxidation ◽  
Density Functional ◽  
Carbon Nitride ◽  
Density Functional Theory Calculations ◽  
Catalytic Performance ◽  
Functional Theory ◽  
Spin Polarized ◽  
Planar Carbon

The catalytic performance of Pd/Pt embedded planar carbon nitride for CO oxidation has been investigated via spin-polarized density functional theory calculations.

CO oxidation by MoS2-supported Au19 nanoparticles: effects of vacancy formation and tensile strain

2016 ◽  
Vol 18 (19) ◽  
pp. 13232-13238 ◽  
Author(s):  
Soonho Kwon ◽  
Kihyun Shin ◽  
Kihoon Bang ◽  
Hyun You Kim ◽  
Hyuck Mo Lee
Keyword(s):  
Density Functional Theory ◽  
Co Oxidation ◽  
Catalytic Oxidation ◽  
Density Functional ◽  
Tensile Strain ◽  
Density Functional Theory Calculations ◽  
Vacancy Formation ◽  
Oxidation Of Co ◽  
Functional Theory ◽  
Catalytic Oxidation Of Co

The mechanism of the catalytic oxidation of CO activated by MoS2-supported Au19 nanoparticles (NPs) was studied using density functional theory calculations.

The interplay between structural perfectness and CO oxidation catalysis on aluminum, phosphorous and silicon complexes of corroles

2019 ◽  
Vol 21 (14) ◽  
pp. 7661-7674 ◽  
Author(s):  
Afshan Mohajeri ◽  
Nasim Hassani
Keyword(s):  
Density Functional Theory ◽  
Carbon Monoxide ◽  
Co Oxidation ◽  
Catalytic Oxidation ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Oxidation Catalysis ◽  
Functional Theory ◽  
Oxidation Of Carbon Monoxide

Catalytic oxidation of carbon monoxide on perfect and defective structures of corrole complexes with aluminum, phosphorous and silicon have been investigated by performing density functional theory calculations.

scholarly journals Caryolene-forming carbocation rearrangements

2013 ◽  
Vol 9 ◽  
pp. 323-331 ◽  
Author(s):  
Quynh Nhu N Nguyen ◽  
Dean J Tantillo
Keyword(s):  
Density Functional Theory ◽  
Proton Transfer ◽  
Energy Barrier ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Intramolecular Proton Transfer ◽  
The Other ◽  
Orbital Symmetry ◽  
Functional Theory ◽  
Biosynthetic Precursor

Density functional theory calculations on mechanisms of the formation of caryolene, a putative biosynthetic precursor to caryol-1(11)-en-10-ol, reveal two mechanisms for caryolene formation: one involves a base-catalyzed deprotonation/reprotonation sequence and tertiary carbocation minimum, whereas the other (with a higher energy barrier) involves intramolecular proton transfer and the generation of a secondary carbocation minimum and a hydrogen-bridged minimum. Both mechanisms are predicted to involve concerted suprafacial/suprafacial [2 + 2] cycloadditions, whose asynchronicity allows them to avoid the constraints of orbital symmetry.

THEORETICAL STUDY ON CUI-CATALYZED LIGAND-FREE N-ARYLATION OF IMIDAZOLE WITH BROMOBENZENE

2012 ◽  
Vol 11 (05) ◽  
pp. 1135-1147 ◽  
Author(s):  
HAN GUO ◽  
YING XUE
Keyword(s):  
Free Energy ◽  
Energy Barrier ◽  
Density Functional ◽  
Oxidative Addition ◽  
Reductive Elimination ◽  
Free Energy Barrier ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Ligand Free ◽  
Rate Limiting

The density functional theory (DFT) is used to investigate the mechanism of ligand-free CuI -catalyzed N -arylation of imidazole with aryl halide. The oxidative addition/reductive elimination mechanism is adopted via two different pathways to form the same Cu(III) intermediate. Comparing two pathways, the path 1 in which the imidazolyl coordination occurs prior to the oxidative addition is more favorable, because the free energy barrier of the rate-limiting step of path 1 is lower than the barrier of the other. In addition, it leads to a relative stable intermediate which can promote the reaction to process via path 1. And the overall free energy barrier of oxidative addition to imidazole-ligated Cu(I) complex is not high enough when comparing with the diamine-promote process, which can further prove that the N -arylation of imidazole is feasible in the absence of additional ligands. Nucleophile coordination and reductive elimination steps are facile, while the oxidative addition is the rate-limiting step.

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