In-situ Monitoring of the Structure of a Goethite-Based Catalyst during Methane Oxidation by X-Ray Absorption Near-Edge Structure (XANES) Spectroscopy Assisted by Chemometric Methods

2011 ◽  
Vol 65 (6) ◽  
pp. 692-697 ◽  
Author(s):  
Cleiton A. Nunes ◽  
Eliane C. Resende ◽  
Iara R. Guimarães ◽  
Alexandre S. Anastácio ◽  
Mário C. Guerreiro
Keyword(s):  
Methane Oxidation ◽  
In Situ Monitoring ◽  
Xanes Spectroscopy ◽  
Chemometric Methods ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption

Revealing differences in the chemical form of zinc in brain tissue using K-edge X-ray absorption near-edge structure spectroscopy

Metallomics ◽  
2020 ◽  
Author(s):  
Ashley L. Hollings ◽  
Virginie Lam ◽  
Ryu Takechi ◽  
John C. L. Mamo ◽  
Juliane Reinhardt ◽  
...  
Keyword(s):  
Brain Tissue ◽  
Chemical Form ◽  
Xanes Spectroscopy ◽  
Edge Structure ◽  
X Ray ◽  
Rodent Brain ◽  
Zn Speciation ◽  
X Ray Absorption

This study demonstrates the use of X-ray absorption near-edge structure (XANES) spectroscopy at the Zn K-edge to study the chemical form of Zn (Zn speciation) in situ within rodent brain tissue.

Sulfur in wheat gluten: In situ analysis by X-ray absorption near edge structure (XANES) spectroscopy

2001 ◽  
Vol 212 (5) ◽  
pp. 570-575 ◽  
Author(s):  
Alexander Prange ◽  
Nils Kühlsen ◽  
Barbara Birzele ◽  
Isolde Arzberger ◽  
Josef Hormes ◽  
...  
Keyword(s):  
Wheat Gluten ◽  
In Situ Analysis ◽  
Xanes Spectroscopy ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption

scholarly journals High-energy resolution X-ray absorption and emission spectroscopy reveals insight into unique selectivity of La-based nanoparticles for CO2

2015 ◽  
Vol 112 (52) ◽  
pp. 15803-15808 ◽  
Author(s):  
Ofer Hirsch ◽  
Kristina O. Kvashnina ◽  
Li Luo ◽  
Martin J. Süess ◽  
Pieter Glatzel ◽  
...  
Keyword(s):  
Energy Resolution ◽  
Emission Spectroscopy ◽  
High Energy ◽  
Unit Cell ◽  
High Energy Resolution ◽  
Electron Configuration ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption

The lanthanum-based materials, due to their layered structure and f-electron configuration, are relevant for electrochemical application. Particularly, La2O2CO3 shows a prominent chemoresistive response to CO2. However, surprisingly less is known about its atomic and electronic structure and electrochemically significant sites and therefore, its structure–functions relationships have yet to be established. Here we determine the position of the different constituents within the unit cell of monoclinic La2O2CO3 and use this information to interpret in situ high-energy resolution fluorescence-detected (HERFD) X-ray absorption near-edge structure (XANES) and valence-to-core X-ray emission spectroscopy (vtc XES). Compared with La(OH)3 or previously known hexagonal La2O2CO3 structures, La in the monoclinic unit cell has a much lower number of neighboring oxygen atoms, which is manifested in the whiteline broadening in XANES spectra. Such a superior sensitivity to subtle changes is given by HERFD method, which is essential for in situ studying of the interaction with CO2. Here, we study La2O2CO3-based sensors in real operando conditions at 250 °C in the presence of oxygen and water vapors. We identify that the distribution of unoccupied La d-states and occupied O p- and La d-states changes during CO2 chemoresistive sensing of La2O2CO3. The correlation between these spectroscopic findings with electrical resistance measurements leads to a more comprehensive understanding of the selective adsorption at La site and may enable the design of new materials for CO2 electrochemical applications.

scholarly journals Performance of secondary P-fertilizers in pot experiments analyzed by phosphorus X-ray absorption near-edge structure (XANES) spectroscopy

AMBIO ◽  
2017 ◽  
Vol 47 (S1) ◽  
pp. 62-72 ◽  
Author(s):  
Christian Vogel ◽  
Camille Rivard ◽  
Verena Wilken ◽  
Andreas Muskolus ◽  
Christian Adam
Keyword(s):  
Xanes Spectroscopy ◽  
Edge Structure ◽  
X Ray ◽  
Pot Experiments ◽  
X Ray Absorption ◽  
P Fertilizers

Fluorescence Extended X-Ray Absorption Fine Structure Study on Local Structures of Rare-Earth-Doped InGaGdN

2016 ◽  
Vol 1133 ◽  
pp. 429-433
Author(s):  
Siti Nooraya Mohd Tawil ◽  
Shuichi Emura ◽  
Daivasigamani Krishnamurthy ◽  
Hajime Asahi
Keyword(s):  
Fine Structure ◽  
Rare Earth ◽  
Nearest Neighbor ◽  
Structure Study ◽  
Edge Structure ◽  
X Ray ◽  
Local Structures ◽  
Absorption Fine ◽  
X Ray Absorption

Local structures around gadolinium atoms in rare-earth (RE)-doped InGaGdN thin films were studied by means of fluorescence extended X-ray absorption fine structure (EXAFS) measured at the Gd LIII-edges. The samples were doped with Gd in-situ during growth by plasma-assisted molecular beam epitaxy (PAMBE). Gd LIII-edge EXAFS signal from the GaGdN, GdN and Gd foil were also measured as reference. The X-ray absorption near edge structure (XANES) spectra around Gd LIII absorption edge of InGaGdN samples observed at room temperature indicated the enhancement of intensities with the increase of Gd composition. Further EXAFS analysis inferred that the Gd atoms in InGaN were surrounded by similar atomic shells as in the case of GaGdN with the evidence indicating majority of Gd atoms substituted into Ga sites of InGaGdN. A slight elongation of bond length for the 2nd nearest-neighbor (Gd–Ga) of sample with higher Gd concentration was also observed.

In situ XANES Study of Co2+ Ion Adsorption on Fe3O4 Nanoparticles in Supercritical Aqueous Fluids

2012 ◽  
Vol 1383 ◽  
Author(s):  
Hao Yan ◽  
Robert A. Mayanovic ◽  
Joseph Demster ◽  
Alan J. Anderson
Keyword(s):  
Angular Momentum ◽  
Density Of States ◽  
Fe3o4 Nanoparticles ◽  
Ion Adsorption ◽  
Edge Structure ◽  
X Ray ◽  
Peak Fitting ◽  
X Ray Absorption ◽  
In Situ Xanes

ABSTRACTIn situ x-ray absorption spectroscopy (XAS) measurements were made on Fe3O4 nanoparticles in supercritical aqueous fluids to 500 °C in order to study their reactivity with Co2+ aqua ions and to investigate the structural properties of the reacted nanoparticles. The analyses of the x-ray absorption near edge structure (XANES) of XAS indicate that reactivity of Fe3O4 nanoparticles with Co2+ ions is minimal to 200 °C but becomes significant in the 250–500 °C temperature range. XANES and angular momentum projected density of states (l-DOS) calculations were carried out using the FEFF8.2 code and analyses were made using multi-peak fitting to determine the origin of the features exhibited in the spectra.

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