scholarly journals A Theoretical Study on the Inclusion of Fe, Cu, and Zn in Illite Clays

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Antonio Sánchez-Coronilla ◽  
Elisa I. Martín ◽  
Francisco José Fernández-de-Cordova ◽  
Francisco Javier Santos ◽  
José Hidalgo Toledo
Keyword(s):  
Dft Calculations ◽  
Oxidation State ◽  
Coordination Sphere ◽  
Theoretical Study ◽  
Oxidation States ◽  
Adsorption Characteristic ◽  
Periodic Dft Calculations ◽  
Periodic Dft ◽  
Cu And Zn ◽  
Oxygen Interaction

The inclusion of Fe, Cu, and Zn in (1, 0, 0), (0, 0.5, 0), and (0.5, 0.5, 0.5) sites of an illite with the KAl2Si4O12H2 structure has been studied. For the inclusion of the metals, their common oxidation states were chosen, that is, 0, +2, +3 and 0, +1, +2, for Fe and Cu, respectively, while 0 and +2 for Zn. Periodic DFT calculations were performed to know the most favourable site of incorporation of the ions. Energetically the most favourable site for the inclusion corresponds to the (1, 0, 0) coordinate for all the ions independently of their oxidation state. However, the highest oxidation state of the metals (Fe3+, Cu2+, and Zn2+) was the most favoured for being incorporated into the illite structure and was the selected ion for the discussion. In those structures, metal oxygen interaction plays an important role in stabilizing the systems. Structural and energetic results indicate that illite presents good adsorption characteristic of those Fe3+, Cu2+, and Zn2+ in the (1, 0, 0) site. Thus, those ions may be available for plants for its extraction by phytoextraction techniques and the consequent soil regeneration. The inclusion of a second metallic ion revealed the most favourable inclusion corresponding to the inclusion of Fe3+ ion. The inclusion of this ion modifies the coordination sphere around the first metal being available for subsequent extraction by phytoremediation or other techniques for clean-up of the soil and its regeneration.

scholarly journals Unraveling reaction networks behind the catalytic oxidation of methane with H2O2 over a mixed-metal MIL-53(Al,Fe) MOF catalyst

2018 ◽  
Vol 9 (33) ◽  
pp. 6765-6773 ◽  
Author(s):  
Ágnes Szécsényi ◽  
Guanna Li ◽  
Jorge Gascon ◽  
Evgeny A. Pidko
Keyword(s):  
Dft Calculations ◽  
Catalytic Oxidation ◽  
Metal Organic Framework ◽  
Reaction Networks ◽  
Reaction Paths ◽  
Mixed Metal ◽  
Oxidation Of Methane ◽  
Metal Organic ◽  
Periodic Dft Calculations ◽  
Periodic Dft

Reaction paths underlying the catalytic oxidation of methane with H2O2 over an Fe containing MIL-53(Al) metal–organic framework were studied by periodic DFT calculations.

Mn-Doped black phosphorene for ultrasensitive hydrogen sulfide detection: periodic DFT calculations

2020 ◽  
Vol 22 (27) ◽  
pp. 15549-15558 ◽  
Author(s):  
Mahdi Ghadiri ◽  
Mohammad Ghashghaee ◽  
Mehdi Ghambarian
Keyword(s):  
Hydrogen Sulfide ◽  
Dft Calculations ◽  
Work Function ◽  
Electrical Conductance ◽  
Black Phosphorus ◽  
Mn Doping ◽  
Black Phosphorene ◽  
Periodic Dft Calculations ◽  
Mn Doped ◽  
Periodic Dft

A drastic improvement in both the electrical conductance and work function sensitivities of black phosphorus monolayer to H2S through Mn doping is reported. The operation of the modified nanosensor is more promising than for the pristine material.

New Bond-Valence Sum Model

1997 ◽  
Vol 53 (6) ◽  
pp. 885-894 ◽  
Author(s):  
J. P. Naskar ◽  
S. Hati ◽  
D. Datta
Keyword(s):  
Oxidation State ◽  
Coordination Sphere ◽  
Metal Ion ◽  
Nickel Complexes ◽  
Bond Valence ◽  
Oxidation States ◽  
Linear Variation ◽  
Axial Bond ◽  
Inorganic Complexes ◽  
Bond Valence Sum

A new expression is devised empirically to accommodate zero and some negative oxidation states in the bond-valence sum approach. The method is worked out in detail for a number of homoleptic copper and nickel complexes of various coordinating atoms in several oxidation states of the metals. An implication of the expression is a linear variation between 1/r eq and 1/r ax in octahedral MX 6 moieties, where r eq and r ax are, respectively, the average equatorial and axial bond lengths. This is verified in Cu2+ X 6 chromophores for X = F, O, N and S. The usefulness of the new expression in assessing the compatibility of a coordination sphere with an oxidation state of a metal ion is demonstrated by exemplary applications to some inorganic complexes, azurin and urease.

Adsorption and hydrogenation mechanism of crotonaldehyde on a Pd(111) surface by periodic DFT calculations

RSC Advances ◽  
2014 ◽  
Vol 4 (51) ◽  
pp. 27003-27012 ◽  
Author(s):  
Wei Shi ◽  
Lianyang Zhang ◽  
Zheming Ni ◽  
Xuechun Xiao ◽  
Shengjie Xia
Keyword(s):  
Dft Calculations ◽  
Partial Hydrogenation ◽  
Primary Mechanism ◽  
Periodic Dft Calculations ◽  
Periodic Dft

The parallel adsorption of crotonaldehyde to the Pd(111) surface at the fcc–hcp site through the CC and CO is the most stable. The full hydrogenation mechanism follows the steps O → C2 → C3 → C1 to generate the product of n-butane. For the partial hydrogenation, the 1,4-addition is identified as a primary mechanism.

Reexamination of formic acid decomposition on the Pt(111) surface both in the absence and in the presence of water, from periodic DFT calculations

2015 ◽  
Vol 5 (6) ◽  
pp. 3322-3332 ◽  
Author(s):  
Yuanyuan Qi ◽  
Jingjing Li ◽  
Dongju Zhang ◽  
Chengbu Liu
Keyword(s):  
Dft Calculations ◽  
Formic Acid ◽  
Co Poisoning ◽  
Acid Decomposition ◽  
Formic Acid Decomposition ◽  
Periodic Dft Calculations ◽  
Periodic Dft

The calculated results in literatures for the decomposition of formic acid on Pt(111) into CO cannot rationalize the well-known easy CO poisoning of Pt-based catalysts.

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