Structural Transformations in Platinum Supported on y-Alumina Studied by X-Ray Absorption Spectroscopy

1987 ◽  
Vol 111 ◽  
Author(s):  
H. J. Robota ◽  
M. J. Cohn ◽  
A. Z. Ringwelski ◽  
R. A. Eades
Keyword(s):  
Absorption Spectroscopy ◽  
Room Temperature ◽  
Structural Transformations ◽  
X Ray ◽  
Disordered Phase ◽  
Chemisorbed Oxygen ◽  
Initial Reduction ◽  
Highly Dispersed ◽  
X Ray Absorption

AbstractPt particles in a highly dispersed Pt/γ-A12O3 catalyst have been found to undergo ordering following the removal of chemisorbed oxygen with hydrogen at room temperature. The very small Pt particles are found to be disordered following an initial reduction at 500°C. Treating the ordered phase of Pt at 500°C in hydrogen is found to restore the disordered phase.

scholarly journals Chemisorbed Oxygen or Surface Oxides Steer the Selectivity in Pd Electrocatalytic Propene Oxidation Observed by Operando Pd Ledge X‐ray Absorption Spectroscopy

2021 ◽  
Author(s):  
Sergey Koroidov ◽  
Anna Winiwarter ◽  
Oscar Alfonso Diaz-Morales ◽  
Mikaela Gorlin ◽  
Joakim Halldin Stenlid ◽  
...  
Keyword(s):  
Electrochemical Oxidation ◽  
Absorption Spectroscopy ◽  
Propene Oxidation ◽  
X Ray ◽  
Chemisorbed Oxygen ◽  
Oxidation Of Hydrocarbons ◽  
Surface Oxides ◽  
X Ray Absorption

Controlled electrochemical oxidation of hydrocarbons to desired products is an attractive approach in catalysis. Here we study the electrochemical propene oxidation under operando conditions using Pd L‐edge X‐ray absorption spectroscopy...

scholarly journals Soft x-ray absorption spectroscopy of metalloproteins and high-valent metal-complexes at room temperature using free-electron lasers

2017 ◽  
Vol 4 (5) ◽  
pp. 054307 ◽  
Author(s):  
Markus Kubin ◽  
Jan Kern ◽  
Sheraz Gul ◽  
Thomas Kroll ◽  
Ruchira Chatterjee ◽  
...  
Keyword(s):  
Metal Complexes ◽  
Absorption Spectroscopy ◽  
Free Electron ◽  
Room Temperature ◽  
Free Electron Lasers ◽  
X Ray ◽  
High Valent ◽  
X Ray Absorption

Probing origin of room temperature ferromagnetism in Ni ion implanted ZnO films with x-ray absorption spectroscopy

2012 ◽  
Vol 111 (1) ◽  
pp. 013715 ◽  
Author(s):  
P. Srivastava ◽  
S. Ghosh ◽  
B. Joshi ◽  
P. Satyarthi ◽  
P. Kumar ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Zno Films ◽  
X Ray ◽  
X Ray Absorption ◽  
Ion Implanted

Recovery of nanosize zinc from phosphor wastes with an ionic liquid

2009 ◽  
Vol 6 (3) ◽  
pp. 268 ◽  
Author(s):  
Hsin-Liang Huang ◽  
H. Paul Wang ◽  
Edward M. Eyring ◽  
Juu-En Chang
Keyword(s):  
Ionic Liquid ◽  
Absorption Spectroscopy ◽  
Room Temperature ◽  
Bond Distance ◽  
Extraction Process ◽  
Room Temperature Ionic Liquid ◽  
Zns Nanoparticles ◽  
Recovery Method ◽  
X Ray ◽  
X Ray Absorption

Environmental context. Very fine phosphor ashes are discharged from particulate collection systems (such as bag houses) in the cathode ray tube or television disassembling processes. Effective recovery of ZnO and ZnS nanoparticles from the phosphor ash can be achieved by extraction with a room temperature ionic liquid. By synchrotron radiation X-ray absorption spectroscopy, the obtained molecular scale data turn out to be very useful in revealing speciation of zinc in the extraction process, which also facilitates the development of a simple nanoparticle recovery method. Abstract. An effective, simple method has been developed for the recovery of ZnO and ZnS nanoparticles from hazardous phosphor ash waste. Experimentally, zinc (77%) in the phosphor ash (that contains mainly zinc (91%)) can be recovered by extraction with a room temperature ionic liquid (RTIL) ([C4mim][PF6], 1-butyl-3-methylimidazolium hexafluorophosphate). Component fitted X-ray absorption near edge structure (XANES) spectra of zinc indicate that metallic zinc (Zn) (9%) in the phosphor ash can be dissolved to form a Zn2+–1-methylimidazole ([mim]) complex during extraction with the RTIL. ZnS and ZnO nanoparticles (60–61%) can also be extracted from the phosphor. Over the 298–523 K temperature range, desired ZnO/ZnS ratios (0.3–0.6) can be obtained since interconversion of ZnS to ZnO in the RTIL is temperature dependent. The Fourier transformed extended X-ray absorption fine structure (EXAFS) data also show that the nanosize ZnS extracted in the RTIL possesses a Zn–S bond distance of 2.33 Å with coordination numbers (CNs) of 3.6–3.7. At 523 K, in the RTIL, ~30% of the ZnS is oxidised to form octahedral ZnO (with a bond distance of 2.10 Å and a CN of 6.1) that may coat the surfaces of the ZnS nanoparticles. This work exemplifies the utilisation of X-ray absorption spectroscopy (EXAFS and XANES) to reveal speciation and possible reaction pathways in a nanoparticle extraction process (with a RTIL) in detail.

scholarly journals X-ray Absorption Spectroscopy Studies of the Room-Temperature Ferromagnetic Fe-Doped 6H-BaTiO3

2014 ◽  
Vol 98 (4) ◽  
pp. 1156-1161 ◽  
Author(s):  
Iuliia Mikulska ◽  
Matjaz Valant ◽  
Iztok Arčon ◽  
Darja Lisjak
Keyword(s):  
Absorption Spectroscopy ◽  
Room Temperature ◽  
X Ray ◽  
Spectroscopy Studies ◽  
X Ray Absorption

Defects in room-temperature ferromagnetic Cu-doped ZnO films probed by x-ray absorption spectroscopy

2012 ◽  
Vol 24 (30) ◽  
pp. 306002 ◽  
Author(s):  
Q Ma ◽  
J T Prater ◽  
C Sudakar ◽  
R A Rosenberg ◽  
J Narayan
Keyword(s):  
Absorption Spectroscopy ◽  
Room Temperature ◽  
Zno Films ◽  
X Ray ◽  
Doped Zno ◽  
X Ray Absorption

Studies on Nanostructured M50 Type Steel Using X-Ray Absorption Spectroscopy and NMR

1994 ◽  
Vol 351 ◽  
Author(s):  
Mahalingam Balasubramanian ◽  
Y.D. Zhang ◽  
J.I. Budnick ◽  
K.E. Gonsalves ◽  
T.D. Xiao
Keyword(s):  
Magnetic Properties ◽  
Long Range ◽  
Absorption Spectroscopy ◽  
Near Neighbor ◽  
Long Range Order ◽  
X Ray ◽  
Type Steel ◽  
Disordered Phase ◽  
Structural And Magnetic Properties ◽  
X Ray Absorption

ABSTRACTWe have investigated the local structural and magnetic properties of Fe in nanostructured Fe-Cr-Mo-V-C M50 type steel. Experimental techniques which we used include XAFS and NMR. NMR results on as-synthesized M50 type steel shows that the material contains a small amount of bcc Fe plus some other highly disordered phase(s). XAFS measurements indicate that the near neighbor coordinations around Fe are not simply well ordered bcc or fcc Fe and that the sample doesn't have long range crystalline order. XAFS measurements on the consolidated sample show that Fe is predominantly in the form of bcc Fe with good long range order.

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