H-FER-Catalyzed Conversion of Methanol to Ethanol and Dimethyl Ether: a First-Principles DFT Study

ABSTRACT Methanol adsorption and dehydration reactions within zeolites represent important steps in the catalytic conversion process to form long-chain hydrocarbons. Herein, first-principles density functional theory (DFT) is employed in the determination of methanol adsorption and conversion in ferrierite (FER), where we predict the fundamental adsorption geometries and energetics of methanol adsorption. The methanol molecule is shown to physisorb at all explored binding sites, stabilized through hydrogen-bonded interactions with the acid site atOmeth-Hframbond distances ranging from 1.33-1.51 A. We demonstrate that the zeolites' adsorption capability is affected by the silicon/aluminium ratio, with stronger adsorptions predicted in the material with silicon to aluminium fractions of 5 than 8. The adsorption strength is also found to vary depending on the tetrahedral binding site, with the T1O2 site yielding the most stable methanol adsorption structure in the Si/Al ratio = 5(Eads = -22.5 kcal mol-1), whereas the T1O1 site yields the most stable adsorption geometry (Eads = -19.2 kcal mol-1) in the Si/Al ratio = 8. Upon translational and rotational motion, methanol is protonated resulting in the breaking of its C-O bond to form a methoxy species bound to the framework oxygen (O-CH3 distance of 1.37 A), whereas the water molecule is stabilized at the acid site through H-bonding (Owat-H = 2.0 A). Further reaction between the methoxy species and a second methanol molecule results in the formation of ethanol and protonated dimethyl ether, with adsorption energies of -42 and -25 kcal mol-1, respectively. The results in this study provide atomistic insight into the effect of acidity of the FER zeolite on the adsorption and conversion of methanol. Keywords: Zeolites, ferrierite, methanol adsorption, acid sites, density functional theory (DFT).

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The Damping Term, from First Principles

10.1093/oso/9780198788669.003.0006 ◽

2017 ◽

Author(s):

Olle Eriksson ◽

Anders Bergman ◽

Lars Bergqvist ◽

Johan Hellsvik

Keyword(s):

Density Functional Theory ◽

First Principles ◽

Density Functional ◽

Spin Dynamics ◽

Damping Term ◽

Functional Theory ◽

Basic Principles ◽

Sham Equation ◽

Damping Parameter ◽

Simulation Cell

In the previous chapters we described the basic principles of density functional theory, gave examples of how accurate it is to describe static magnetic properties in general, and derived from this basis the master equation for atomistic spin-dynamics; the SLL (or SLLG) equation. However, one term was not described in these chapters, namely the damping parameter. This parameter is a crucial one in the SLL (or SLLG) equation, since it allows for energy and angular momentum to dissipate from the simulation cell. The damping parameter can be evaluated from density functional theory, and the Kohn-Sham equation, and it is possible to determine its value experimentally. This chapter covers in detail the theoretical aspects of how to calculate theoretically the damping parameter. Chapter 8 is focused, among other things, on the experimental detection of the damping, using ferromagnetic resonance.

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Electron-phonon interaction in In-induced √7 ×√3 structures on Si(111) from first-principles

Physical Chemistry Chemical Physics ◽

10.1039/d0cp05234e ◽

2021 ◽

Author(s):

I. Yu. Sklyadneva ◽

Rolf Heid ◽

Pedro Miguel Echenique ◽

Evgueni Chulkov

Keyword(s):

Density Functional Theory ◽

Double Layer ◽

First Principles ◽

Linear Response ◽

Density Functional ◽

Single Layer ◽

Phonon Interaction ◽

Functional Theory ◽

Electron Phonon Interaction ◽

The Density Functional Theory

Electron-phonon interaction in the Si(111)-supported rectangular √(7 ) ×√3 phases of In is investigated within the density-functional theory and linear-response. For both single-layer and double-layer √(7 ) ×√3 structures, it...

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Adsorption of the Gas Molecules (NH3, C2H6O, C3H6O, CO, H2S) on noble metal (Ag, Au, Pt, Pd, Ru)–Doped MoSe2 Monolayer: A First-Principles Study

New Journal of Chemistry ◽

10.1039/d1nj01705e ◽

2021 ◽

Author(s):

Lanjuan Zhou ◽

Sujing Yu ◽

Yan Yang ◽

Qi Li ◽

Tingting Li ◽

...

Keyword(s):

Density Functional Theory ◽

Noble Metal ◽

First Principles ◽

Density Functional ◽

Noble Metals ◽

Gas Sensing ◽

Functional Theory ◽

First Principles Study ◽

Gas Molecules ◽

Sensing Performance

In this paper, the effects of five noble metals (Au, Pt, Pd, Ag, Ru) doped MoSe2 on improving gas sensing performance were predicted through density functional theory (DFT) based on...

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Geometric, electronic properties of Au$_l$Pt$_m$ ($l$+$m$$\leqslant$10) clusters: A first-principles study

Physical Chemistry Chemical Physics ◽

10.1039/d0cp05642a ◽

2021 ◽

Author(s):

Wei-Feng Xie ◽

Hao-Ran Zhu ◽

Shi-Hao Wei

Keyword(s):

Density Functional Theory ◽

Electronic Properties ◽

First Principles ◽

Density Functional ◽

Inverse Design ◽

Functional Theory ◽

First Principles Study

The structural evolutions and electronic properties of Au$_l$Pt$_m$ ($l$+$m$$\leqslant$10) clusters are investigated by using the first$-$principles methods based on density functional theory (DFT). We use Inverse design of materials by...

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

RSC Advances ◽

10.1039/d1ra03218f ◽

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.

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Hydrogenation and oxidation enhances the thermoelectric performance of Si2BN monolayer

New Journal of Chemistry ◽

10.1039/d0nj06000c ◽

2021 ◽

Author(s):

H. R. Mahida ◽

Deobrat Singh ◽

Yogesh Sonvane ◽

Sanjeev K. Gupta ◽

P. B. Thakor ◽

...

Keyword(s):

Density Functional Theory ◽

Charge Transport ◽

Transport Properties ◽

First Principles ◽

Density Functional ◽

Thermoelectric Performance ◽

First Principles Calculations ◽

Functional Theory

In the present study, we have investigated the structural, electronic, and charge transport properties of pristine, hydrogenated, and oxidized Si2BN monolayers via first-principles calculations based on density functional theory (DFT).

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Flexoelectricity in atomic monolayers from first principles

Nanoscale ◽

10.1039/d0nr07803d ◽

2020 ◽

Author(s):

Shashikant Kumar ◽

David Codony ◽

Irene Arias ◽

Phanish Suryanarayana

Keyword(s):

Density Functional Theory ◽

Transition Metal ◽

Ab Initio ◽

First Principles ◽

Density Functional ◽

Transition Metal Dichalcogenides ◽

Functional Theory ◽

Group Iii ◽

Flexoelectric Effect ◽

Metal Dichalcogenides

We study the flexoelectric effect in fifty-four select atomic monolayers using ab initio Density Functional Theory (DFT). Specifically, considering representative materials from each of Group III monochalcogenides, transition metal dichalcogenides...

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Theoretical Study of Zirconium Isomorphous Substitution into Zeolite Frameworks

Molecules ◽

10.3390/molecules24244466 ◽

2019 ◽

Vol 24 (24) ◽

pp. 4466

Author(s):

Duichun Li ◽

Bin Xing ◽

Baojun Wang ◽

Ruifeng Li

Keyword(s):

Acid Site ◽

Density Functional ◽

Theoretical Study ◽

Atomic Radius ◽

Acid Sites ◽

Isomorphous Substitution ◽

Dispersion Correction ◽

Brønsted Acidity ◽

Functional Theory ◽

Brönsted Acidity

Systematic periodic density functional theory computations including dispersion correction (DFT-D) were carried out to determine the preferred location site of Zr atoms in sodalite (SOD) and CHA-type topology frameworks, including alumino-phosphate-34 (AlPO-34) and silico-alumino-phosphate-34 (SAPO-34), and to determine the relative stability and Brönsted acidity of Zr-substituted forms of SOD, AlPO-34, and SAPO-34. Mono and multiple Zr atom substitutions were considered. The Zr substitution causes obvious structural distortion because of the larger atomic radius of Zr than that of Si, however, Zr-substituted forms of zeolites are found to be more stable than pristine zeolites. Our results demonstrate that in the most stable configurations, the preferred favorable substitutions of Zr in substituted SOD have Zr located at the neighboring sites of the Al-substituted site. However, in the AlPO-34 and SAPO-34 frameworks, the Zr atoms are more easily distributed in a dispersed form, rather than being centralized. Brönsted acidity of substituted zeolites strongly depends on Zr content. For SOD, substitution of Zr atoms reduces Brönsted acidity. However, for Zr-substituted forms of AlPO-34 and SAPO-34, Brönsted acidity of the Zr-O(H)-Al acid sites are, at first, reduced and, then, the presence of Zr atoms substantially increased Brönsted acidity of the Zr-O(H)-Al acid site. The results in the SAPO-34-Zr indicate that more Zr atoms substantially increase Brönsted acidity of the Si-O(H)-Al acid site. It is suggested that substituted heteroatoms play an important role in regulating and controlling structural stability and Brönsted acidity of zeolites.

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Oxygen-evolution reactions (OER) on transition-metal-doped Fe3Co(PO4)4 iron-phosphate surfaces: a first-principles study

Catalysis Science & Technology ◽

10.1039/d1cy00302j ◽

2021 ◽

Author(s):

Yogeshwaran Krishnan ◽

Sateesh Bandaru ◽

Niall J. English

Keyword(s):

Density Functional Theory ◽

Transition Metal ◽

Oxygen Evolution ◽

First Principles ◽

Density Functional ◽

Iron Phosphate ◽

Functional Theory ◽

First Principles Study ◽

Metal Doped ◽

Catalyst Surfaces

A series of transition-metal-doped Fe1−xMxCo(PO4)4(010) and Fe3Co1−xMx(PO4)4(010) electro-catalyst surfaces (with M = Mn, Os, Ru, Rh and Ir) have been modelled via density-functional theory (DFT) to gauge their oxygen-evolution reactions (OER).

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Effect of dispersion on surface interactions of cobalt(ii) octaethylporphyrin monolayer on Au(111) and HOPG(0001) substrates: a comparative first principles study

Physical Chemistry Chemical Physics ◽

10.1039/c4cp01762e ◽

2014 ◽

Vol 16 (27) ◽

pp. 14096-14107 ◽

Cited By ~ 38

Author(s):

Bhaskar Chilukuri ◽

Ursula Mazur ◽

K. W. Hipps

Keyword(s):

Density Functional Theory ◽

Electronic Properties ◽

First Principles ◽

Density Functional ◽

Surface Interactions ◽

Dispersion Interactions ◽

Functional Theory ◽

First Principles Study ◽

Conductive Surfaces

Implication of dispersion interactions on geometric, adsorption and electronic properties of porphyrin monolayer on conductive surfaces using density functional theory.

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