Structural and electronic properties of Fe and TiFe from extended and near-edge x-ray-absorption structure

1983 ◽  
Vol 27 (8) ◽  
pp. 4712-4721 ◽  
Author(s):  
N. Motta ◽  
M. De Crescenzi ◽  
A. Balzarotti
Keyword(s):  
Electronic Properties ◽  
X Ray ◽  
Structural And Electronic Properties ◽  
X Ray Absorption

Properties of Pure and Sulfided NiMoO4 and CoMoO4 Catalysts: Tpr, Xanes and Time-Resolved XRD Studdzs

1997 ◽  
Vol 497 ◽  
Author(s):  
S. Chaturvedi ◽  
J. A. Rodriguez ◽  
J. C. Hanson ◽  
A. Albornoz ◽  
J. L. Brito
Keyword(s):  
Electronic Properties ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
Direct Transformation ◽  
X Ray ◽  
Β Phase ◽  
Structural And Electronic Properties ◽  
X Ray Absorption ◽  
Kinetics Of ◽  
Cobalt And Nickel

ABSTRACTX-ray absorption near-edge spectroscopy (XANES) was used to characterize the structural and electronic properties of a series of cobalt- and nickel-molybdate catalysts (AMoO4.nH20, α-AMoO4, β-AMoO4; A= Co or Ni). The results of XANES indicate that the Co and Ni atoms are in octahedral sites in all these compounds, while the coordination of Mo varies from octahedral in the a-phases to tetrahedral in the β-phases and hydrate. Time-resolved x-ray diffraction shows a direct transformation of the hydrates into the β-AMoO4 compounds (following a kinetics of first order) at temperatures between 200 and 350 °C. This is facilitated by the similarities that the AMoO4.nH20 and β-AMoO4 compounds have in their structural and electronic properties. The molybdates react with H 2 at temperatures between 400 and 600 °C, forming gaseous water and oxides in which the oxidation state of Co and Ni remains +2 while that of Mo is reduced to +5 or +4. After exposing α-NiMoO4 and P-NiMoO4 to H2S, both metals get sulfided and a NiMoSx phase is formed. For the β phase of NiMoO4 the sulfidation of Mo is more extensive than for the a phase, making the former a better precursor for catalysts of hydrodesulfurization reactions.

Operando X-ray absorption investigations into the role of Fe in the electrochemical stability and oxygen evolution activity of Ni1−xFexOy nanoparticles

2018 ◽  
Vol 6 (47) ◽  
pp. 24534-24549 ◽  
Author(s):  
Daniel F. Abbott ◽  
Emiliana Fabbri ◽  
Mario Borlaf ◽  
Francesco Bozza ◽  
Robin Schäublin ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Oxygen Evolution ◽  
Rock Salt ◽  
Electrochemical Stability ◽  
Rock Salt Structure ◽  
X Ray ◽  
Structural And Electronic Properties ◽  
Salt Structure ◽  
X Ray Absorption

The structural and electronic properties of rock salt-type Ni–Fe oxides are investigated under OER conditions. The inclusion of Fe in the rock-salt structure is shown to inhibit the transformation to more layered and disordered polymorphs.

Structural and electronic properties of molecularly adsorbed CS2 on Cu(111) studied by X-ray absorption and photoelectron spectroscopies

1994 ◽  
Vol 311 (1-2) ◽  
pp. 172-180 ◽  
Author(s):  
S. Yagi ◽  
T. Yokoyama ◽  
Y. Kitajima ◽  
Y. Takata ◽  
T. Kanazawa ◽  
...  
Keyword(s):  
Electronic Properties ◽  
X Ray ◽  
Structural And Electronic Properties ◽  
X Ray Absorption

Studies of Structural and Electronic Properties of Uranium Compounds, by XANES Spectroscopy

2005 ◽  
Vol 893 ◽  
Author(s):  
Clara Fillaux ◽  
Christophe Den Auwer ◽  
Dominique Guillaumont ◽  
Eric Simoni ◽  
Nicole Barré ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Electronic Transitions ◽  
Final States ◽  
Edge Structure ◽  
X Ray ◽  
Structural And Electronic Properties ◽  
Bonding Properties ◽  
Experimental Data Analysis ◽  
X Ray Absorption ◽  
Coordination Polyhedrons

AbstractX-ray absorption near edge structure (XANES) is a sensitive probe of the electronic structure, and can provide information about the valency, the unoccupied electronic states and the effective charge of the absorbing atom. In this paper, near edge x-ray absorption fine structure spectra are reported at the L3, M5 and N5 thresholds and used to determined structural and electronic properties of U(VI) within uranyl nitrate (UO2(NO3)2.6H2O) and perovskite (Ba2ZnUO6). Experimental data analysis by simulating the absorption edge allows to compare the coordination polyhedrons, identify the electronic transitions and calculate the density of states associated with the absorption spectra. Moreover, a coupling between simulations of the experimental spectra and quantum chemical calculations is performed, in order to improve the model describing the final states and better understand the bonding properties of the cation with the ligand.

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