scholarly journals Dynamics of Oxidation of Reduced Forms of CO2 under Electrochemical and Open-Сircuit Conditions on Polycrystalline Pt in H2CO3

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 274
Author(s):  
Alexander V. Smolin ◽  
Мikhail N. Mikhailov ◽  
Aleksey F. Gadzaov ◽  
Leonid M. Kustov
Keyword(s):  
Quantum Chemical ◽  
Preliminary Analysis ◽  
Oxidation Reaction ◽  
Density Functional ◽  
Oxidation Process ◽  
Open Circuit ◽  
Organic Substances ◽  
Oxidation Of Co ◽  
Reduced Forms

The problem of identifying correlations between catalytic and electrocatalytic processes is one of the fundamental problems of catalysis among “simple” organic substances, and the oxidation of CO and rCO2 is of great interest, since CO and CO2 are considered in pairs both during catalytic and electrocatalytic transformations. In the case of electrocatalysis, this analysis is important in the study of fuel cells. In this paper, we studied the correlation between the oxidation of reduced forms of CO2 (rCO2) under potentiodynamic-galvanoctatic electrochemical and open-circuit conditions of measurements on polycrystalline (pc)Pt in H2CO3. Periodic oscillations are revealed at the oxidation of Had and rCO2 on (pc)Pt. Quantum chemical calculations were carried out on the Pt13 cluster in order to identify the mechanisms of the rCO2 oxidation reaction. The correspondence in the energy parameters of the oxidation process of rCO2 under open-circuit conditions and electrochemical conditions is shown. The preliminary analysis of the system using density functional (DFT) calculations is carried out and the most stable systems that are based on Pt13 are found, namely rOH-Pt13-(CO)n, rOH-Pt13-(COH) and rOH-Pt13-(rCOOH). OH• species was chosen as the most likely candidate for the role of the oxidant for rCO2. Preliminary calculations for the expected reactions were carried out, and the optimal PES is revealed.

scholarly journals Density-functional theory models of Fe(iv)O reactivity in metal–organic frameworks: self-interaction error, spin delocalisation and the role of hybrid exchange

2020 ◽  
Vol 22 (22) ◽  
pp. 12821-12830
Author(s):  
Fernan Saiz ◽  
Leonardo Bernasconi
Keyword(s):  
Density Functional Theory ◽  
Oxidation Reaction ◽  
Density Functional ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Metal Organic ◽  
Organic Framework

We study the reactivity of Fe(iv)O moieties supported by a metal–organic framework (MOF-74) in the oxidation reaction of methane to methanol using all-electron, periodic density-functional theory calculations.

Density functional theory (DFT) studies of CO oxidation reaction on M13 and Au18M clusters (M = Au, Ag, Cu, Pt and Pd): the role of co-adsorbed CO molecule

RSC Advances ◽  
2016 ◽  
Vol 6 (61) ◽  
pp. 55867-55877 ◽  
Author(s):  
Wenping Zeng ◽  
Jian Tang ◽  
Pu Wang ◽  
Yong Pei
Keyword(s):  
Density Functional Theory ◽  
Co Oxidation ◽  
Oxidation Reaction ◽  
Density Functional ◽  
Model Systems ◽  
Dft Studies ◽  
Functional Theory ◽  
Co Oxidation Reaction ◽  
Adsorbed Co

Using the icosahedra M13 (M = Au, Ag, Cu, Pt, Pd) and heteroatom doped Au18M clusters as model systems, the role of the co-adsorbed CO molecule played in the CO oxidation reaction is explored on the basis of density functional theory (DFT) calculations.

scholarly journals Structure and separation quality of various N- and O-donor ligands from quantum-chemical calculations

Nukleonika ◽  
2015 ◽  
Vol 60 (4) ◽  
pp. 847-851 ◽  
Author(s):  
Michael Trumm ◽  
Bernd Schimmelpfennig ◽  
Andreas Geist
Keyword(s):  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Density Functional ◽  
Donor Ligands ◽  
Field Development ◽  
Force Field Development ◽  
The Density Functional Theory ◽  
Complexation Reactions

Abstract Although BTP (2,6-di(1,2,4-triazin-3-yl)pyridine) has been proven to be a highly effective N-donor ligand for the selective An(III)/Ln(III) separation, the origin of its selectivity is still under discussion. We present in this paper quantum-chemical calculations at the density functional theory (DFT) and MP2 level which highlight the role of the aquo ions in the separation process. Furthermore these data will be the reference for future force-field development to investigate the differences in An(III) complexation reactions compared to their Ln(III) counterparts.

THE ROLE OF SUBSTRATE IN PACKING STRUCTURES OF SEXITHIOPHENES ON AG (111) SURFACE: MOLECULAR DYNAMICS SIMULATIONS AND QUANTUM CHEMICAL CALCULATIONS

2009 ◽  
Vol 08 (04) ◽  
pp. 677-690 ◽  
Author(s):  
JIN WEN ◽  
JING MA
Keyword(s):  
Molecular Dynamics ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Density Functional ◽  
Md Simulations ◽  
Site Preference ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Dynamics Simulations

Packing structures and orientation of sexithiophene (6T) molecules on Ag (111) surface are investigated by molecular dynamics (MD) simulations and quantum chemical calculations. Both the cluster and the slab models are employed. The density functional theory and molecular mechanism calculations demonstrate a weak physisorption and little site-preference in thiophene/ Ag (111) system. The MD simulations show that in the first layer close to the surface, the nearly coplanar 6T strips lie parallel with long axes deviating from [Formula: see text] direction about 20° – 30° and 75° – 90°. The average adsorption height of the monolayer is about 3.2 Å with most of the sulfur atoms in thienyl rings sitting on the bridge site of Ag (111) surface. The 6T molecules tend to take tilted orientations when they are far away from the surface. The packing structures of 6T layers deposited on the surface resulted from the competition between the molecule–substrate and intermolecular interactions.

Exploring the reducing role of boron: added insights from theory

2016 ◽  
Vol 45 (14) ◽  
pp. 5978-5988 ◽  
Author(s):  
Yuvraj Dangat ◽  
Kumar Vanka
Keyword(s):  
Density Functional Theory ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Density Functional ◽  
Functional Theory ◽  
Co Coupling ◽  
Full Quantum

Why are boron containing systems so effective at CO coupling? Full quantum chemical calculations with density functional theory (DFT) provide interesting insights into why recently reported CO coupling by diboryne systems is such a facile process.

scholarly journals Electrochemical and quantum chemical study to assess the role of (2E)-2-(furan-2-ylmethylidene) hydrazine carbothioamide as inhibitor for acid corrosion of mild steel

2021 ◽  
Author(s):  
V. R. Adinarayanan ◽  
P. Preethi Kumari ◽  
Suma A. Rao
Keyword(s):  
Mild Steel ◽  
Quantum Chemical ◽  
Density Functional ◽  
Electrochemical Impedance ◽  
Acid Corrosion ◽  
Quantum Chemical Study ◽  
Activation Parameters ◽  
Chemical Study ◽  
Clear Insight

AbstractSynthesis and inhibition effectiveness of (2E)-2-(furan-2-ylmethylidene) hydrazine carbothioamide (FMHC) as an inhibitor for corrosion of mild steel in 0.5 M H2SO4 is reported. Experiments were conducted at various temperatures (303–323 K) by adopting potentiodynamic polarization and electrochemical impedance spectroscopy. Readings obtained demonstrated that percentage inhibition efficiency (% IE) improved with the upsurge in the concentration of FMHC, while it decreased with a rise in temperature. The highest % IE observed was 60% for 2.5 × 10–4 M FMHC at 303 K. FMHC worked moderately as a mixed inhibitor. FMHC obeyed the Langmuir model of adsorption and the mode of adsorption was physisorption on the mild steel surface which was further endorsed by examining the surface using the scanning electron microscope. A clear insight into the mechanistic features of corrosion inhibition by using FMHC was acquired. Calculation of activation parameters helped to suggest an appropriate mechanism for the adsorption of FMHC on mild steel through quantum chemical calculations using density functional theory (DFT). Graphical abstract

The Nature of S-N Bonding in Sulfonamides and Related Compounds: Insights into π-Bonding Contributions from Sulfur K-Edge XAS

2020 ◽  
Author(s):  
Tulin Okbinoglu ◽  
Pierre Kennepohl
Keyword(s):  
Density Functional ◽  
Chemical Properties ◽  
Functional Theory ◽  
Rotational Barriers ◽  
Td Dft ◽  
Nitrogen Bonds ◽  
X Ray Absorption ◽  
Related Compounds ◽  
And Chemical Properties

Molecules containing sulfur-nitrogen bonds, like sulfonamides, have long been of interest due to their many uses and chemical properties. Understanding the factors that cause sulfonamide reactivity is important, yet their continues to be controversy regarding the relevance of S-N π bonding in describing these species. In this paper, we use sulfur K-edge x-ray absorption spectroscopy (XAS) in conjunction with density functional theory (DFT) to explore the role of S<sub>3p</sub> contributions to π-bonding in sulfonamides, sulfinamides and sulfenamides. We explore the nature of electron distribution of the sulfur atom and its nearest neighbors and extend the scope to explore the effects on rotational barriers along the sulfur-nitrogen axis. The experimental XAS data together with TD-DFT calculations confirm that sulfonamides, and the other sulfinated amides in this series, have essentially no S-N π bonding involving S<sub>3p</sub> contributions and that electron repulsion and is the dominant force that affect rotational barriers.

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