Insight into the adsorption and dissociation of CH4 on Pt(hkl) surfaces: A theoretical study

2012 ◽  
Vol 258 (18) ◽  
pp. 7154-7160 ◽  
Author(s):  
Riguang Zhang ◽  
Luzhi Song ◽  
Yuhan Wang
Keyword(s):  
Theoretical Study ◽  
Adsorption And Dissociation ◽  
Insight Into

Through-Space Transmission of 19F-13C Coupling Via an Intermediate Bond. An Experimental and Theoretical Study

1987 ◽  
Vol 40 (12) ◽  
pp. 1923 ◽  
Author(s):  
ID Rae ◽  
ID Rae ◽  
A Staffa ◽  
A Staffa ◽  
AC Diz ◽  
...  
Keyword(s):  
Theoretical Study ◽  
Lone Pair ◽  
Electron Excitation ◽  
Carbonyl Groups ◽  
Polarization Propagator ◽  
Close Proximity ◽  
Fermi Contact ◽  
Intramolecular Hydrogen ◽  
Intermediate Bond ◽  
Insight Into

In order to obtain a deeper insight into the title effect, several compounds with an F atom very close to a C-H of a nearby functional group were synthesized and the relevant couplings measured. The most conspicuous case was that of 8-fluoro-2-hydroxynaphthalene-1-carbaldehyde where a close proximity between the F and H atoms is the result of fluorine-oxygen repulsion and the formation of an intramolecular hydrogen bond between the hydroxyl and carbonyl groups. The experimental four-bond J(F,CHO) coupling is 26.2 Hz. A compound very similar to this one, but without the OH group, was chosen on which to perform a polarization propagator analysis of the through-space (TS) coupling pathways, at the RPA-INDO level. The expression for the TS coupling in terms of the projected polarization propagator and perturbators was numerically analysed. It is found that this coupling is completely dominated by a TS component of the Fermi contact (FC) term, the main features of which are: ( i ) It decays exponentially with the F-H distance; (ii) Its main contribution comes from an electron excitation involving the F lone-pair, the C-H bond of the CHO moiety and its corresponding antibonding orbital;(iii) The π-type lone-pair does not contribute to the TS coupling pathway of the FC term.

Theoretical insight into adsorption and dissociation of water on NiCr binary alloy surfaces: Early-stage oxidation mechanism

2021 ◽  
Vol 130 (11) ◽  
pp. 115303
Author(s):  
Ya-Ru Yin ◽  
Cui-Lan Ren ◽  
Zhao-Feng Liang ◽  
Jian-Xing Dai ◽  
He-Fei Huang ◽  
...  
Keyword(s):  
Binary Alloy ◽  
Early Stage ◽  
Oxidation Mechanism ◽  
Adsorption And Dissociation ◽  
Theoretical Insight ◽  
Insight Into

H3O2 Bridging Ligand in a Metal–Organic Framework. Insight into the Aqua-Hydroxo↔Hydroxyl Equilibrium: A Combined Experimental and Theoretical Study

2013 ◽  
Vol 135 (15) ◽  
pp. 5782-5792 ◽  
Author(s):  
Richard F. D’Vries ◽  
Victor A. de la Peña-O’Shea ◽  
Natalia Snejko ◽  
Marta Iglesias ◽  
Enrique Gutiérrez-Puebla ◽  
...  
Keyword(s):  
Theoretical Study ◽  
Metal Organic Framework ◽  
Bridging Ligand ◽  
Metal Organic ◽  
Insight Into ◽  
Organic Framework

A Theoretical Insight Into the Multi-Level Governance

2019 ◽  
pp. 1-22
Author(s):  
Dilek Dede
Keyword(s):  
European Union ◽  
Literature Review ◽  
Theoretical Study ◽  
Research Question ◽  
The European Union ◽  
Foreign Politics ◽  
Multi Level ◽  
European Union Studies ◽  
Theoretical Insight ◽  
Insight Into

Multi-level governance has been described as an updated form of governance that began in the early 1990s. The traditional distinction between domestic and foreign politics was eliminated in the same period. This study aims at clarifying the concept of multi-level governance in both the Europeanization literature and the European Union studies. The research question is, What are the definitions, dynamics, characteristics of multi-level governance in both the Europeanization literature and the European Union studies? In methodology, it is a theoretical study that remains on literature review.

Dissociation of H2O molecule adsorbed on Si (001) 2×1 surface: a theoretical study

2008 ◽  
Vol 1145 ◽  
Author(s):  
Hyun-Chul Oh ◽  
Hwa-Il Seo ◽  
Yeong-Cheol Kim
Keyword(s):  
Water Molecule ◽  
Room Temperature ◽  
Surface Coverage ◽  
Theoretical Study ◽  
Surface Model ◽  
Water Molecules ◽  
First Principles Calculations ◽  
Adsorption Sites ◽  
Adsorption Surface ◽  
Adsorption And Dissociation

AbstractThe adsorption and dissociation behavior of water molecule below and above the critical dissociation temperatures were studied by first principles calculations. We found that water-molecule adsorption (surface coverage, θ=0.25) on the down Si atom of a Si dimer in two dimers surface model was 0.26 eV more favorable than that on the up Si atom. The activation energies of water molecule on the down Si atom for interdimer and intradimer dissociations were 0.17 eV and 0.20 eV, respectively. Due to the lower activation energy, the water molecule splits into H and OH immediately once it adsorbs on down Si atom of the Si (001) surface at room temperature. There were three different adsorption sites among four sites of the two dimers for the second water molecule (θ=0.5): one was preoccupied by OH of the first water molecule; up Si atom of the same-dimer with 76.3 % probability, up Si atom of the adjacent-dimer with 23.6 % probability, and down Si atom of the adjacent-dimer with 0.1 % probability. Thus, ½ monolayer of OH sites on the Si (001) surface are irregularly distributed when water molecules are adsorbed and dissociated at room temperature.

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