Selective Recovery of Molybdenum over Rhenium from Molybdenite Flue Dust Leaching Solution Using PC88A Extractant

Selective solvent extraction of molybdenum over rhenium from molybdenite (MoS2) flue dust leaching solution was studied. In the present work, thermodynamic calculations of the chemical equilibria in aqueous solution were first performed, and the potential–pH diagram for the Mo–Re–SO42−–H2O system was constructed. With the gained insight on the system, 2-ethylhexyl phosphonic acid mono-(2-ethylhexyl)-ester (PC88A) diluted in kerosene was used as the extractant agent. Keeping constant the reaction temperature and aqueous-to-organic phase ratio (1:1), organic phase concentration and pH were the studied experimental variables. It was observed that by increasing the acidity of the solution and extractant concentration, selectivity towards Mo extraction increased, while the opposite was true for Re extraction. Selective Mo removal (+95%) from leach solution containing ca. 9 g/L Mo and 0.5 g/L Re was achieved when using an organic phase of 5% PC88A at pH = 0. No rhenium was coextracted during 10 min of extraction time at room temperature. Density functional theory (DFT) calculations were performed in order to study the interactions of organic extractants with Mo and Re ions, permitting a direct comparison of calculation results with the experimental data to estimate selectivity factors in Mo–Re separation. For this aim, PC88A and D2EHPA (di-(2-ethylhexyl) phosphoric acid) were simulated. The interaction energies of D2EHPA were shown to be higher than those of PC88A, which could be due to its stronger capability for complex formation. Besides, it was found that the interaction energies of both extractants follow this trend considering Mo species: MoO22+ > MoO42−. It was also demonstrated through DFT calculations that the interaction energies of D2EHPA and PC88A with species are based on these trends, respectively: MoO22+ > MoO42− > ReO4− and MoO22+ > ReO4− > MoO42−, in qualitative agreement with the experimental findings.

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Influence of the adsorption of toxic agents on the optical and electronic properties of B12N12 fullerene in the presence and absence of an external electric field

New Journal of Chemistry ◽

10.1039/d0nj01868f ◽

2020 ◽

Vol 44 (34) ◽

pp. 14513-14528

Author(s):

Alireza Soltani ◽

Mohammad Ramezanitaghartapeh ◽

Masoud Bezi Javan ◽

Mohammad T. Baei ◽

Andrew Ng Kay Lup ◽

...

Keyword(s):

Density Functional Theory ◽

Electric Field ◽

Dft Calculations ◽

Electronic Properties ◽

External Electric Field ◽

Density Functional ◽

Interaction Energies ◽

Functional Theory ◽

Toxic Agents ◽

Optical And Electronic Properties

The interaction energies and optoelectronic properties of sarin (SF) and chlorosarin (SC) on the B12N12 with and without the presence of an electric field have been studied using density functional theory (DFT) calculations.

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A theoretical study of weak interactions in phenylenediamine homodimer clusters

Physical Chemistry Chemical Physics ◽

10.1039/c6cp04922b ◽

2016 ◽

Vol 18 (42) ◽

pp. 29249-29257 ◽

Cited By ~ 16

Author(s):

Chengqian Yuan ◽

Haiming Wu ◽

Meiye Jia ◽

Peifeng Su ◽

Zhixun Luo ◽

...

Keyword(s):

Density Functional Theory ◽

Dft Calculations ◽

Intermolecular Interactions ◽

Density Functional ◽

Theoretical Study ◽

Natural Bond Orbital ◽

Weak Interactions ◽

Interaction Energies ◽

Functional Theory ◽

Weak Intermolecular Interactions

Utilizing dispersion-corrected density functional theory (DFT) calculations, we demonstrate the weak intermolecular interactions of phenylenediamine dimer (pdd) clusters, emphasizing the local lowest energy structures and decomposition of interaction energies by natural bond orbital (NBO) and atoms in molecule (AIM) analyses.

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Preparation of Zirconium Oxide Powder Using Zirconium Carboxylate Precursors

Advances in Physical Chemistry ◽

10.1155/2014/429751 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 4

Author(s):

Mohammed H. Al-Hazmi ◽

YongMan Choi ◽

Allen W. Apblett

Keyword(s):

Dft Calculations ◽

Density Functional ◽

Dissociative Adsorption ◽

Gravimetric Analysis ◽

X Ray Diffraction ◽

Functional Theory ◽

Experimental Findings ◽

Periodic Dft Calculations ◽

Good Agreement

Zirconia was prepared at low temperatures (<450°C) using single several source precursors based on zirconium carboxylates where the R groups were systematically varied. The combination of density functional theory (DFT) calculations and extensive characterization of the precursors (i.e., X-ray diffraction, thermal gravimetric analysis, infrared spectroscopy, and scanning electron microscopy) indicated that the carboxylic acid complexes may link the zirconium metal with a cis bidentate configuration. Periodic DFT calculations were performed to examine the interaction between monoclinic ZrO2 and propanoic acid. Dissociative adsorption takes place through the cis bidentate structure with an adsorption energy of −1.43 eV. Calculated vibrational frequencies using the optimized structure are in good agreement with experimental findings.

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Simulating Surfactant-Iron Oxide Interfaces: From Density Functional Theory to Molecular Dynamics

10.26434/chemrxiv.8325356 ◽

2019 ◽

Author(s):

Carlos Ayestaran Latorre ◽

James Ewen ◽

Chiara Gattinoni ◽

Daniele Dini

Keyword(s):

Molecular Dynamics ◽

Density Functional Theory ◽

Iron Oxide ◽

Dft Calculations ◽

Density Functional ◽

Md Simulations ◽

Oxide Surfaces ◽

Interaction Energies ◽

Functional Theory ◽

Oxide Interfaces

<div>Understanding the behaviour of surfactant molecules on iron oxide surfaces is important for many industrial applications. Molecular dynamics (MD) simulations of such systems have been limited by the absence of a force-feild (FF) which accurately describes the molecule-surface interactions. In this study, interaction energies from density functional theory (DFT) + U calculations with a van der Waals functional are used to parameterize a classical FF for MD simulations of amide surfactants on iron oxide surfaces. The Original FF, which was derived using mixing rules and surface Lennard-Jones (LJ) parameters developed for nonpolar molecules, were shown to signi cantly underestimate the adsorption energy and overestimate the equilibrium adsorption distance compared to DFT. Conversely, the Optimized FF showed excellent agreement with the interaction energies obtained from DFT calculations for a wide range of surface coverages and molecular conformations near to and adsorbed on a-Fe2O3(0001). This was facilitated through the use of a Morse potential for strong chemisorption interactions, modi fied LJ parameters for weaker physisorption interactions, and adjusted partial charges for the electrostatic interactions. The Original FF and Optimized FF were compared in classical nonequilibrium molecular dynamics (NEMD) simulations of amide molecules con fined between iron oxide surfaces. When the Optimized FF was employed, the amide molecules were pulled closer to the surface and the orientation of the headgroups was more similar to that observed in the DFT calculations compared to the Original FF. The Optimized FF proposed here facilitates classical MD simulations of amide-iron oxide interfaces in which the interactions are representative of accurate DFT calculations.</div>

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Simulating Surfactant-Iron Oxide Interfaces: From Density Functional Theory to Molecular Dynamics

10.26434/chemrxiv.8325356.v1 ◽

2019 ◽

Author(s):

Carlos Ayestaran Latorre ◽

James Ewen ◽

Chiara Gattinoni ◽

Daniele Dini

Keyword(s):

Molecular Dynamics ◽

Density Functional Theory ◽

Iron Oxide ◽

Dft Calculations ◽

Density Functional ◽

Md Simulations ◽

Oxide Surfaces ◽

Interaction Energies ◽

Functional Theory ◽

Oxide Interfaces

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From Intermolecular Interaction Energies and Observable Shifts to Component Contributions and Back Again: A Tale of Variational Energy Decomposition Analysis

Annual Review of Physical Chemistry ◽

10.1146/annurev-physchem-090419-115149 ◽

2021 ◽

Vol 72 (1) ◽

pp. 641-666

Author(s):

Yuezhi Mao ◽

Matthias Loipersberger ◽

Paul R. Horn ◽

Akshaya Das ◽

Omar Demerdash ◽

...

Keyword(s):

Dft Calculations ◽

Intermolecular Interaction ◽

Density Functional ◽

Decomposition Analysis ◽

Radical Cations ◽

Energy Decomposition Analysis ◽

Interaction Energies ◽

Energy Decomposition ◽

Functional Theory ◽

Pauli Repulsion

Quantum chemistry in the form of density functional theory (DFT) calculations is a powerful numerical experiment for predicting intermolecular interaction energies. However, no chemical insight is gained in this way beyond predictions of observables. Energy decomposition analysis (EDA) can quantitatively bridge this gap by providing values for the chemical drivers of the interactions, such as permanent electrostatics, Pauli repulsion, dispersion, and charge transfer. These energetic contributions are identified by performing DFT calculations with constraints that disable components of the interaction. This review describes the second-generation version of the absolutely localized molecular orbital EDA (ALMO-EDA-II). The effects of different physical contributions on changes in observables such as structure and vibrational frequencies upon complex formation are characterized via the adiabatic EDA. Example applications include red- versus blue-shifting hydrogen bonds; the bonding and frequency shifts of CO, N2, and BF bound to a [Ru(II)(NH3)5]2 + moiety; and the nature of the strongly bound complexes between pyridine and the benzene and naphthalene radical cations. Additionally, the use of ALMO-EDA-II to benchmark and guide the development of advanced force fields for molecular simulation is illustrated with the recent, very promising, MB-UCB potential.

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Structural and computational analysis of intermolecular interactions in a new 2-thiouracil polymorph

Acta Crystallographica Section C Structural Chemistry ◽

10.1107/s205322961701542x ◽

2017 ◽

Vol 73 (12) ◽

pp. 1078-1086 ◽

Cited By ~ 2

Author(s):

Ivana Fabijanić ◽

Dubravka Matković-Čalogović ◽

Viktor Pilepić ◽

Krešimir Sanković

Keyword(s):

Hydrogen Bonds ◽

Dft Calculations ◽

Density Functional ◽

Computational Analysis ◽

Noncovalent Interaction ◽

Monoclinic Space Group ◽

Interaction Energies ◽

X Ray Diffraction ◽

Space Group ◽

Intermolecular Contacts

The crystallization and characterization of a new polymorph of 2-thiouracil by single-crystal X-ray diffraction, Hirshfeld surface analysis and periodic density functional theory (DFT) calculations are described. The previously published polymorph (A) crystallizes in the triclinic space group P\overline{1}, while that described herein (B) crystallizes in the monoclinic space group P21/c. Periodic DFT calculations showed that the energies of polymorphs A and B, compared to the gas-phase geometry, were −108.8 and −29.4 kJ mol−1, respectively. The two polymorphs have different intermolecular contacts that were analyzed and are discussed in detail. Significant differences in the molecular structure were found only in the bond lengths and angles involving heteroatoms that are involved in hydrogen bonds. Decomposition of the Hirshfeld fingerprint plots revealed that O...H and S...H contacts cover over 50% of the noncovalent contacts in both of the polymorphs; however, they are quite different in strength. Hydrogen bonds of the N—H...O and N—H...S types were found in polymorph A, whereas in polymorph B, only those of the N—H...O type are present, resulting in a different packing in the unit cell. QTAIM (quantum theory of atoms in molecules) computational analysis showed that the interaction energies for these weak-to-medium strength hydrogen bonds with a noncovalent or mixed interaction character were estimated to fall within the ranges 5.4–10.2 and 4.9–9.2 kJ mol−1 for polymorphs A and B, respectively. Also, the NCI (noncovalent interaction) plots revealed weak stacking interactions. The interaction energies for these interactions were in the ranges 3.5–4.1 and 3.1–5.5 kJ mol−1 for polymorphs A and B, respectively, as shown by QTAIM analysis.

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Density Functional Theory Study on Mechanism of Mercury Removal by CeO2 Modified Activated Carbon

Energies ◽

10.3390/en11112872 ◽

2018 ◽

Vol 11 (11) ◽

pp. 2872 ◽

Cited By ~ 2

Author(s):

Li Zhao ◽

Yang-wen Wu ◽

Jian Han ◽

Han-xiao Wang ◽

Ding-jia Liu ◽

...

Keyword(s):

Density Functional Theory ◽

Activated Carbon ◽

Dft Calculations ◽

Flue Gas ◽

Density Functional ◽

Mercury Removal ◽

Partial Density ◽

Functional Theory ◽

Langmuir Hinshelwood Mechanism ◽

Calculation Results

Doping of CeO2 on activated carbon (AC) can promote its performance for mercury abatement in flue gas, while the Hg0 removal mechanism on the AC surface has been rarely reported. In this research, density functional theory (DFT) calculations were implemented to unveil the mechanism of mercury removal on plain AC and CeO2 modified AC (CeO2-AC) sorbents. Calculation results indicate that Hg0, HCl, HgCl and HgCl2 are all chemisorbed on the adsorbent. Strong interaction and charge transfer are shown by partial density of states (PDOS) analysis of the Hg0 adsorption configuration. HCl, HgCl and HgCl2 can be dissociatively adsorbed on the AC model and subsequently generate HgCl or HgCl2 released to the gas phase. The adsorption energies of HgCl and HgCl2 on the CeO2-AC model are relatively high, indicating a great capacity for removing HgCl and HgCl2 in flue gas. DFT calculations suggest that AC sorbents exhibit a certain catalytic effect on mercury oxidation, the doping of CeO2 enhances the catalytic ability of Hg0 oxidation on the AC surface and the reactions follow the Langmuir–Hinshelwood mechanism.

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Solvent Extraction of Sc(III) by D2EHPA/TBP from the Leaching Solution of Vanadium Slag

Metals ◽

10.3390/met10060790 ◽

2020 ◽

Vol 10 (6) ◽

pp. 790

Author(s):

Xuejiao Cao ◽

Ting-an Zhang ◽

Weiguang Zhang ◽

Guozhi Lv

Keyword(s):

Solvent Extraction ◽

Thermodynamic Analysis ◽

Organic Phase ◽

Species Distribution ◽

Extraction Process ◽

Optimal Conditions ◽

Vanadium Slag ◽

Extractant Concentration ◽

Leaching Solution ◽

Loaded Organic Phase

The solvent extraction of scandium by the mixture of di-(2-ethylhexyl) phosphate (D2EHPA) and tri-n-butyl phosphate (TBP) has been investigated in the acidic leaching solution of vanadium slag. Thermodynamic analysis of the species distribution diagrams on the Sc-S-H2O system showed that scandium mainly exists as Sc3+ and Sc(SO4)+, and sulfur mainly exists as HSO4− in the actual leaching solution of vanadium slag (pH = −0.75). The extraction process was studied to optimize various parameters such as the extractant concentration, dosage of TBP, phase ratio, and stirring speed. The results indicated that 83.64% of scandium and less than 2% of co-extracted elements were extracted under optimal conditions. Then, over 95% of the co-extracted elements and less than 1.1% of scandium were scrubbed from the loaded organic phase by 4.0 mol/L of HCl. Finally, 87.20% of scandium was stripped with 2 mol/L of NaOH and 1 mol/L of NaCl at a stripping O/A of 1:1.

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Structure determination, vibrational bands and chemical shift assignments of 3-(4-(3-(2,5-dimethylphenyl)-3-methylcyclobutyl)thiazol-2-yl)-2-(o-tolyl)thiazolidin-4-one: A combined experimental and quantum chemical density-functional theory studies

Macedonian Journal of Chemistry and Chemical Engineering ◽

10.20450/mjcce.2019.1679 ◽

2019 ◽

Vol 38 (2) ◽

pp. 183

Author(s):

Fatih Şen

Keyword(s):

Dft Calculations ◽

Density Functional ◽

Chemical Shifts ◽

Molecular Geometry ◽

Molecular Structures ◽

Structural Bond ◽

X Ray ◽

X Ray Crystallography ◽

13C Nuclear Magnetic Resonance ◽

Experimental Findings

This paper report is an analysis of the title compound by means of X-ray crystallography, FT-IR, NMR and DFT calculations, in the context of structural and spectral characterization. The crystal and molecular structures of the compound were determined by single-crystal X-ray diffraction (SCXRD). Fourier Transform Infrared (FTIR) spectrum was recorded in the range from 400 cm–1 to 4000 cm–1. The 1H and 13C nuclear magnetic resonance (NMR) spectra were also recorded. DFT calculations were employed to support X-ray molecular geometry and calculate IR and NMR (1H and 13C) spectral bands. The structural (bond lengths, bond angles, torsion angles) and spectral (vibrational modes and chemical shifts) parameters obtained from DFT levels (B3LYP/6-31G(d,p) and B3LYP/6-31G+(d,p)) were compared with experimental findings, and an excellent harmony between the two data was ascertained.

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