The role of the CO adsorption on Pt monolayers supported on flat and stepped Au surfaces: a density functional investigation

RSC Advances ◽  
2014 ◽  
Vol 4 (18) ◽  
pp. 9247-9254 ◽  
Author(s):  
Polina Tereshchuk ◽  
Rafael L. H. Freire ◽  
Juarez L. F. Da Silva
Keyword(s):  
Density Functional ◽  
Co Adsorption ◽  
Metal Films ◽  
Chemical Activity ◽  
Ligand Effects ◽  
Ultrathin Metal Films ◽  
Transition Metal Surfaces ◽  
Substrate Strain ◽  
Functional Investigation

Ultrathin metal films supported on transition-metal surfaces have been considered as promising catalysts as their chemical activity can be controlled by substrate strain, composition, and ligand effects, however, our atomistic understanding of the atomic structure of those systems is far from satisfactory.

Mechanistic Insight into H2S Adsorption and Dissociation on MoP(010): A Density Functional Investigation

2017 ◽  
Vol 1142 ◽  
pp. 300-305
Author(s):  
Gui Xia Li ◽  
Hou Yu Zhu ◽  
Lian Ming Zhao ◽  
Wen Yue Guo ◽  
Xiao Qing Lu ◽  
...  
Keyword(s):  
Density Functional ◽  
Co Adsorption ◽  
Adsorbed Species ◽  
Functional Theory ◽  
Mechanistic Insight ◽  
Structure Sensitive ◽  
Bond Scission ◽  
Functional Investigation ◽  
Adsorption And Dissociation ◽  
Insight Into

H2S adsorption and dissociation on MoP(010) were investigated using density functional theory (DFT) together with periodic slab models. Several different possibilities for H2S, SH, S and H adsorption were considered. Our results show that the H2S, SH and H prefer to adsorb at bridge site, while S adsorbs preferentially at hcp and bridge sites. Additionally, the optimum co-adsorption configurations for SH/H and S/H were determined. The results indicate that the co-adsorbed species repel each other slightly on MoP(010) surface. Finally, the potential energy profile of H2S dissociation on MoP(010) surface was given out. The dissociation energy barriers of the S–H bond scission exhibit that H2S prefers to dissociate on MoP(010) surface. When compared with MoP(001) surface, the obvious differences in H2S decomposition arise demonstrate that the MoP-based catalysts are structure-sensitive.

scholarly journals The role of water co-adsorption on the modification of ZnO nanowires using acetic acid

2014 ◽  
Vol 16 (18) ◽  
pp. 8509-8514 ◽  
Author(s):  
Adriel Domínguez ◽  
Svea grosse Holthaus ◽  
Susan Köppen ◽  
Thomas Frauenheim ◽  
Andreia Luisa da Rosa
Keyword(s):  
Density Functional Theory ◽  
Acetic Acid ◽  
Molecular Dynamic ◽  
Density Functional ◽  
Co Adsorption ◽  
Zno Nanowires ◽  
Molecular Dynamic Simulations ◽  
Dynamic Simulations ◽  
Functional Theory

Density functional theory (DFT) and Car–Parinello molecular dynamic simulations were employed to investigate the interaction of acetic acid with non-polar facets of ultra-thin ZnO nanowires.

Spectroscopic and time-dependent density functional investigation of the role of structure on the acid-base effects of citrinin detection

2017 ◽  
Vol 29 (3) ◽  
pp. 715-723 ◽  
Author(s):  
Michael Appell ◽  
Kervin O. Evans ◽  
David L. Compton ◽  
Lijuan C. Wang ◽  
Wayne B. Bosma
Keyword(s):  
Density Functional ◽  
Time Dependent ◽  
Acid Base ◽  
Functional Investigation ◽  
Dependent Density

scholarly journals Conversion of Carbon Monoxide into Methanol on Alumina-Supported Cobalt Catalyst: Role of the Support and Reaction Mechanism—A Theoretical Study

Catalysts ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 6 ◽  
Author(s):  
Nguyen Ngoc Ha ◽  
Nguyen Thi Thu Ha ◽  
Nguyen Binh Long ◽  
Le Minh Cam
Keyword(s):  
Carbon Monoxide ◽  
Density Functional ◽  
Co Hydrogenation ◽  
Co Adsorption ◽  
Three Dimensional ◽  
Chemical System ◽  
Functional Theory ◽  
Al2o3 Support ◽  
Rate Limiting

Density functional theory (DFT) was used to calculate the step-by-step hydrogenation of carbon monoxide (CO) to form methanol over a Co4 cluster/Al2O3 surface. A three-dimensional Co4 tetrahedral structure was selected to explore its interaction with the supporting Al2O3 (104) surface. Co4 chemically reacted with Al2O3 to form a new chemical system. The calculated results show that Al2O3 support has strengthened the Co4 catalyst during the reaction since the formation of the Co–O bond. Loading Co4 on the Al2O3 surface increases CO adsorption ability but decreases the dissociation ability of C–O to produce hydrocarbons. As such, CH3OH formation becomes more favorable both kinetically and thermodynamically on Co4/Al2O3. In CO hydrogenation, methanol was synthesized through a CO reaction with hydrogen via either an Eley–Rideal or Langmuir–Hinshelwood pathway to form the intermediates C*-O-H, H-C*-OH, H2-C*-OH, and finally the hydrogenation of H2-C*-OH to methanol with both hydrogenation steps forming C*-OH and final product as rate-limiting. These results showed that the interaction between Co, Al2O3 and H2 pressure can change the pathway of CO hydrogenation on Co/Al2O3 and it may, therefore, influence distribution of the final products.

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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