Kinetic analysis of Ag particle redispersion into ZSM-5 in the presence of coke using in situ XAFS

2021 ◽  
Author(s):  
Kazumasa Murata ◽  
Junya Ohyama ◽  
Atsushi Satsuma
Keyword(s):  
Fine Structure ◽  
Kinetic Analysis ◽  
X Ray ◽  
Xafs Spectroscopy ◽  
Absorption Fine ◽  
Ag Particles ◽  
In Situ Xafs ◽  
Ag Particle ◽  
X Ray Absorption

In the present study, the redispersion behavior of Ag particles on ZSM-5 in the presence of coke was observed using in situ X-ray absorption fine structure (XAFS) spectroscopy.

scholarly journals The new X-ray absorption fine-structure beamline with sub-second time resolution at the Taiwan Photon Source

2021 ◽  
Vol 28 (3) ◽  
pp. 930-938
Author(s):  
Chih-Wen Pao ◽  
Jeng-Lung Chen ◽  
Jyh-Fu Lee ◽  
Meng-Che Tsai ◽  
Chi-Yi Huang ◽  
...  
Keyword(s):  
Fine Structure ◽  
Spectral Measurements ◽  
Edge Structure ◽  
X Ray ◽  
Xafs Spectroscopy ◽  
Absorption Fine ◽  
The Stability ◽  
X Ray Absorption ◽  
Photon Source

The new TPS 44A beamline at the Taiwan Photon Source, located at the National Synchrotron Radiation Research Center, is presented. This beamline is equipped with a new quick-scanning monochromator (Q-Mono), which can provide both conventional step-by-step scans (s-scans) and on-the-fly scans (q-scans) for X-ray absorption fine-structure (XAFS) spectroscopy experiments, including X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine-structure (EXAFS) spectral measurements. Ti and Te K-edge XAFS spectra were used to demonstrate the capability of collecting spectra at the limits of the working energy range. The Ni and Cu K-edge XAFS spectra for a Cu-doped Pt/Ni nanocomposite were acquired to test the performance of the newly commissioned beamline. Pt L 3- and Ru K-edge quick-scanning XAFS (QXAFS) spectra for standard Pt and Ru foils, respectively, revealed the stability of the q-scan technique. The results also demonstrated the beamline's ability to collect XAFS spectra on a sub-second timescale. Furthermore, a Zn(s)|Zn2+ (aq)|Cu(s) system was tested to indicate that the states of the Zn electrode could be observed in real time for charging and discharging conditions using an in situ/operando setup combined with QXAFS measurements.

scholarly journals Electrochromic Os-based metallo-supramolecular polymers: electronic state tracking by in situ XAFS, IR, and impedance spectroscopies

RSC Advances ◽  
2020 ◽  
Vol 10 (41) ◽  
pp. 24691-24696
Author(s):  
Takefumi Yoshida ◽  
Manas Kumar Bera ◽  
Yemineni S. L. V. Narayana ◽  
Sanjoy Mondal ◽  
Hitoshi Abe ◽  
...  
Keyword(s):  
Fine Structure ◽  
Electronic State ◽  
Electronic States ◽  
Supramolecular Polymers ◽  
X Ray ◽  
Absorption Fine ◽  
In Situ Xafs ◽  
State Tracking ◽  
X Ray Absorption

In this study, the electronic states of Os-based metallo-supramolecular polymers (poly(OsL)2+) during electrochromism were tracked by in situ X-ray absorption fine structure (XAFS), infrared (IR), and impedance spectroscopies.

scholarly journals Backbonding contributions to small molecule chemisorption in a metal–organic framework with open copper(i) centers

2021 ◽  
Author(s):  
Gregory M. Su ◽  
Han Wang ◽  
Brandon R. Barnett ◽  
Jeffrey R. Long ◽  
David Prendergast ◽  
...  
Keyword(s):  
Fine Structure ◽  
Small Molecule ◽  
Metal Organic Framework ◽  
X Ray ◽  
Metal Site ◽  
Absorption Fine ◽  
Metal Organic ◽  
X Ray Absorption ◽  
Organic Framework

In situ near edge X-ray absorption fine structure spectroscopy directly probes unoccupied states associated with backbonding interactions between the open metal site in a metal–organic framework and various small molecule guests.

Electronic Structures of Crystalline and Aqueous Solutions of LiBr, NaBr, KBr, and KBrO3:  In Situ Br L-Edge Near-edge X-ray Absorption Fine Structure

2003 ◽  
Vol 107 (46) ◽  
pp. 12562-12565 ◽  
Author(s):  
Shuji Matsuo ◽  
Ponnusamy Nachimuthu ◽  
Dennis W. Lindle ◽  
Hisanobu Wakita ◽  
Rupert C. C. Perera
Keyword(s):  
Fine Structure ◽  
Aqueous Solutions ◽  
Electronic Structures ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption

Extended x-ray-absorption fine-structure study of Ag particles isolated in solid argon

1984 ◽  
Vol 30 (2) ◽  
pp. 672-677 ◽  
Author(s):  
P. A. Montano ◽  
W. Schulze ◽  
B. Tesche ◽  
G. K. Shenoy ◽  
T. I. Morrison
Keyword(s):  
Fine Structure ◽  
Structure Study ◽  
X Ray ◽  
Absorption Fine ◽  
Ag Particles ◽  
Solid Argon ◽  
X Ray Absorption

X-Ray Absorption Fine Structure Study in FeTiO3

1997 ◽  
Vol 11 (16n17) ◽  
pp. 745-748 ◽  
Author(s):  
Rebekah Min-Fang Hsu ◽  
Kai-Jan Lin ◽  
Cheng Tien ◽  
Lin-Yan Jang
Keyword(s):  
Absorption Spectrum ◽  
Fine Structure ◽  
Absorption Spectra ◽  
Mixed Valence ◽  
Structure Study ◽  
X Ray ◽  
Xafs Spectroscopy ◽  
Absorption Fine ◽  
Trivalent State ◽  
X Ray Absorption

X-ray absorption fine structure XAFS spectroscopy has been used to determine the valence system for the Fe atom in ilmenite, FeTiO3 . This is the first XAFS data in FeTiO3 to our knowledge. The α- Fe2O3 data served as the standard in determining the ionization of the Fe atom in FeTiO3 . Observation of intensity and k-space are consistent. There was no evidence of mixed valence on comparing the FeTiO3 near edge X-ray absorption spectrum with α- Fe2O3 data. The absorption spectra suggest that iron is in the trivalent state in ilmenite.

Extended X-ray Absorption Fine Structure Studies of GaN Epilayers Doped in situ with Er and Eu During Molecular Beam Epitaxy

2003 ◽  
Vol 798 ◽  
Author(s):  
V. Katchkanov ◽  
J. F. W. Mosselmans ◽  
S. Dalmasso ◽  
K. P. O'Donnell ◽  
R. W. Martin ◽  
...  
Keyword(s):  
Fine Structure ◽  
Rare Earth ◽  
Molecular Beam Epitaxy ◽  
Local Structure ◽  
Molecular Beam ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption ◽  
The Eu

ABSTRACTThe local structure around Er and Eu atoms introduced into GaN epilayers was studied by means of Extended X-ray Absorption Fine Structure above the appropriate rare-earth X-ray absorption edge. The samples were doped in situ during growth by Molecular Beam Epitaxy. The formation of ErN clusters was found in samples with high average Er concentrations of 32±6% and 12.4±0.8%, estimated by Wavelength Dispersive X-ray analysis. When the average Er concentration is decreased to 6.0±0.2%, 1.6±0.2% and 0.17±0.02%, Er is found in localised clusters of ErGaN phase with high local Er content. Similar behaviour is observed for Eu-doped samples. For an average Eu concentration of 30.5±0.5% clusters of pure EuN occur. Decreasing the Eu concentration to 10.4±0.5% leads to EuGaN clusters with high local Eu content. However, for a sample with an Eu concentration of 14.2±0.5% clustering of Eu was not observed.

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.

scholarly journals Recent progress in the performance of HAPG based laboratory EXAFS and XANES spectrometers

2020 ◽  
Vol 35 (10) ◽  
pp. 2298-2304
Author(s):  
Christopher Schlesiger ◽  
Sebastian Praetz ◽  
Richard Gnewkow ◽  
Wolfgang Malzer ◽  
Birgit Kanngießer
Keyword(s):  
Fine Structure ◽  
Recent Progress ◽  
Pyrolytic Graphite ◽  
New Developments ◽  
X Ray ◽  
Xafs Spectroscopy ◽  
Absorption Fine ◽  
Mosaic Crystals ◽  
X Ray Absorption

New developments in the description and modeling of Highly Annealed Pyrolytic Graphite (HAPG) mosaic crystals have led to the possibility of designing optimized optical solutions for X-ray absorption fine structure (XAFS) spectroscopy.

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