CO Coverage Effects on Pt(111) from First-Principles Calculations

2008 ◽  
Vol 1084 ◽  
Author(s):  
Bin Shan ◽  
Ligen Wang ◽  
Jangsuk Hyun ◽  
Yang Sang ◽  
Yujun Zhao ◽  
...  
Keyword(s):  
Density Functional ◽  
Co Adsorption ◽  
Oxidation Catalysis ◽  
Energy Curve ◽  
High Coverage ◽  
Functional Theory ◽  
Diesel Oxidation ◽  
Saturation Coverage ◽  
Differential Binding ◽  
The Stability

ABSTRACTCO saturation coverage on Pt(111) is crucially important in diesel oxidation catalysis. We systematically studied high coverage CO adsorption on the Pt(111) surface using density functional theory (DFT) calculations and classical Monte Carlo (MC) simulations. The zero-coverage limit CO adsorption energy at different binding sites is almost degenerate at the revised Perdew–Burke–Erzernhof functional (RPBE) level. As CO populates the surface, strong through-space repulsion and substrate-mediated metal sharing tends to dominate the stability of adsorbates and alter their binding preferences. The calculated differential binding energy curve and adsorption patterns compare well with experiments.

High coverage adsorption and co-adsorption of CO and H2 on Ru(0001) from DFT and thermodynamics

2015 ◽  
Vol 17 (29) ◽  
pp. 19446-19456 ◽  
Author(s):  
Peng Zhao ◽  
Yurong He ◽  
Dong-Bo Cao ◽  
Xiaodong Wen ◽  
Hongwei Xiang ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Co Adsorption ◽  
High Coverage ◽  
Functional Theory ◽  
Adsorption Of Co ◽  
Atomistic Thermodynamics

The adsorption and co-adsorption of CO and H2 at different coverages on p(4 × 4) Ru(0001) have been computed using periodic density functional theory (GGA-RPBE) and atomistic thermodynamics.

First Principle Study of Hydrazine and OH- Co-Adsorption on Ni(111) in High Coverage System

2014 ◽  
Vol 893 ◽  
pp. 35-38 ◽  
Author(s):  
Andam Deatama Refino ◽  
Mohammad Kemal Agusta ◽  
Hermawan Kresno Dipojono ◽  
Nugraha
Keyword(s):  
Density Functional ◽  
Co Adsorption ◽  
Stable Configuration ◽  
Nickel Surface ◽  
Gauche Conformation ◽  
High Coverage ◽  
Adsorption Mechanisms ◽  
Adsorption Sites ◽  
The Stability ◽  
In Cis

Theoretical investigation of co-adsorption process between hydrazine (N2H4) and OH- on Ni(111) is performed using density functional theory. OH- adsorption mechanisms at various adsorption sites as well as its interaction with hydrazine in various conformations (anti, cis, and gauche) are studied. The stability of OH- adsorption on nickel surface is significantly influenced by the presence of hydrazine molecule. Among the three conformations of hydrazine, OH- adsorption on nickel surface doesn't occur in cis conformation. Otherwise, co-adsorption occurs in system with gauche and anti conformation. In anti system, hydrazine conformation is transformed during relaxation process and forms gauche conformation as the most stable configuration of the system.

DENSITY FUNCTIONAL THEORY STUDY OF Na ON Al(111) AND O ON Ru(0001)

1996 ◽  
Vol 03 (04) ◽  
pp. 1567-1577 ◽  
Author(s):  
C. STAMPFL
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Dissociative Adsorption ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Gradient Corrections ◽  
Saturation Coverage ◽  
The Stability ◽  
Adsorption Systems

The success of density functional theory for the description of the adsorption of atoms on surfaces is well established and, based on recent calculations using gradient corrections, it has been shown that it also describes well the dissociative adsorption of molecules at surfaces — admittedly, however, the database for reactions at surfaces is still somewhat small. In this paper the power of density functional theory calculations is demonstrated through investigations for two different adsorption systems, namely one with a strongly electropositive adsorbate [Na on Al(111)] and one with a strongly electronegative adsorbate [O on Ru(0001)]. In each case, new hitherto unexpected adsorbate phases have been predicted by the theory: for Na on Al(111) the stability of a “four-layer” surface alloy was identified while for O on Ru(0001) it was predicted that the formation of a (1×1)-O adlayer should be possible which implies that the apparent saturation coverage of Θo=1/2 is due to kinetic hindering.

Thermodynamic Stability of Hexagonal and Rhombohedral Bn at Cvd Conditions from Van der Waals Corrected First Principles Calculations

2019 ◽  
Author(s):  
Henrik Pedersen ◽  
Björn Alling ◽  
Hans Högberg ◽  
Annop Ektarawong
Keyword(s):  
Thin Films ◽  
Thermodynamic Stability ◽  
First Principles ◽  
Thermal Equilibrium ◽  
Density Functional ◽  
Van Der Waals ◽  
Chemical Vapor ◽  
First Principles Calculations ◽  
Functional Theory ◽  
The Stability

Thin films of boron nitride (BN), particularly the sp<sup>2</sup>-hybridized polytypes hexagonal BN (h-BN) and rhombohedral BN (r-BN) are interesting for several electronic applications given band gaps in the UV. They are typically deposited close to thermal equilibrium by chemical vapor deposition (CVD) at temperatures and pressures in the regions 1400-1800 K and 1000-10000 Pa, respectively. In this letter, we use van der Waals corrected density functional theory and thermodynamic stability calculations to determine the stability of r-BN and compare it to that of h-BN as well as to cubic BN and wurtzitic BN. We find that r-BN is the stable sp<sup>2</sup>-hybridized phase at CVD conditions, while h-BN is metastable. Thus, our calculations suggest that thin films of h-BN must be deposited far from thermal equilibrium.

Site preference and atomic ordering in the ternary Rh5Ga2As: first-principles calculations

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nilanjan Roy ◽  
Sucharita Giri ◽  
Harshit ◽  
Partha P. Jana
Keyword(s):  
Total Energy ◽  
First Principles ◽  
Density Functional ◽  
Structure Type ◽  
Site Preference ◽  
X Ray Diffraction ◽  
Atomic Ordering ◽  
Functional Theory ◽  
The Stability ◽  
Bonding Characteristics

Abstract The site preference and atomic ordering of the ternary Rh5Ga2As have been investigated using first-principles density functional theory (DFT). An interesting atomic ordering of two neighboring elements Ga and As reported in the structure of Rh5Ga2As by X-ray diffraction data only is confirmed by first-principles total-energy calculations. The previously reported experimental model with Ga/As ordering is indeed the most stable in the structure of Rh5Ga2As. The calculation detected that there is an obvious trend concerning the influence of the heteroatomic Rh–Ga/As contacts on the calculated total energy. Interestingly, the orderly distribution of As and Ga that is found in the binary GaAs (Zinc-blende structure type), retained to ternary Rh5Ga2As. The density of states (DOS) and Crystal Orbital Hamiltonian Population (COHP) are calculated to enlighten the stability and bonding characteristics in the structure of Rh5Ga2As. The bonding analysis also confirms that Rh–Ga/As short contacts are the major driving force towards the overall stability of the compound.

scholarly journals The stability and electronic and photocatalytic properties of the ZnWO4 (010) surface determined from first-principles and thermodynamic calculations

RSC Advances ◽  
2021 ◽  
Vol 11 (38) ◽  
pp. 23477-23490
Author(s):  
Yonggang Wu ◽  
Jihua Zhang ◽  
Bingwei Long ◽  
Hong Zhang
Keyword(s):  
Phase Diagram ◽  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Thermodynamic Calculations ◽  
Photocatalytic Properties ◽  
Thermodynamic Approach ◽  
Functional Theory ◽  
Stability Phase Diagram ◽  
The Stability

The ZnWO4 (010) surface termination stability is studied using a density functional theory-based thermodynamic approach. The stability phase diagram shows that O-Zn, DL-W, and DL-Zn terminations of ZnWO4 (010) can be stabilized.

A DENSITY FUNCTIONAL STUDY OF THE STRUCTURE OF SILANE COUPLING AGENT 3–AMINOPROPYLTRIETHOXYSILANE

2005 ◽  
Vol 04 (01) ◽  
pp. 117-126
Author(s):  
N. L. MA ◽  
P. WU
Keyword(s):  
Coupling Agent ◽  
Density Functional ◽  
Solution Structure ◽  
Silane Coupling Agent ◽  
Industrial Applications ◽  
Functional Study ◽  
Stable Form ◽  
Functional Theory ◽  
Silane Coupling ◽  
The Stability

Using density functional theory, we predicted the solution structure of the hydrolyzed 3–aminopropyltriethoxysilane (h–APS), which is a silane coupling agent commonly used in many industrial applications. We have located five stable minima on the potential energy surface of h–APS in which four of them are "neutral", and the remaining one is zwitterionic (dipolar) in nature. Our calculations suggested that the stability of the most stable form of h–APS in water (denoted as II_N) arose from strong intramolecular OH ⋯ N hydrogen bond. The least stable form is the zwitterionic form (I_ZW), which is estimated to be over 90 kJ mol -1 less stable than II_N. The factors governing the relative stabilities of different forms are discussed.

CHARGE STABILITY AND CONDUCTANCE ANALYSIS OF ANTHRACENE-BASED SINGLE ELECTRON TRANSISTOR

2013 ◽  
Vol 12 (06) ◽  
pp. 1350045 ◽  
Author(s):  
ANURAG SRIVASTAVA ◽  
BODDEPALLI SANTHIBHUSHAN ◽  
PANKAJ DOBWAL
Keyword(s):  
Coulomb Blockade ◽  
Density Functional ◽  
Stability Diagram ◽  
Single Electron ◽  
Single Electron Transistor ◽  
Functional Theory ◽  
Charge Stability ◽  
Anthracene Molecule ◽  
The Stability ◽  
Experimental Values

The present paper discusses the investigation of electronic properties of anthracene-based single electron transistor (SET) operating in coulomb blockade region using Density Functional Theory (DFT) based Atomistix toolkit-Virtual nanolab. The charging energies of anthracene molecule in isolated as well as electrostatic SET environments have been calculated for analyzing the stability of the molecule for different charge states. Study also includes the analysis of SET conductance dependence on source/drain and gate potentials in reference to the charge stability diagram. Our computed charging energies for anthracene in isolated environment are in good agreement with the experimental values and the proposed anthracene SET shows good switching properties in comparison to other acene series SETs.

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