omerelsheikh

omerelsheikh

مدرس - عضو هيئة تدريس

كلية العلوم

العنوان: Sohag

1

إعجاب

المنشورات و المؤلفات التي تحتوي علي الكلمة المفتاحية: EXAFS


A flexible gas flow reaction cell for in situ x-ray absorption spectroscopy studies
A capillary-based sample environment with hot air blower and integrated gas system was developed at Diamond to conduct X-ray absorption spectroscopy (XAS) studies of materials under time-resolved, _in situ_ conditions. The use of a hot air blower, operating in the temperature range of 298-1173 K, allows introduction of other techniques e.g. X-ray diffraction (XRD), Raman spectroscopy for combined techniques studies. ... إقراء المزيد

2018-11-01 02:47:53 الكلمات المفتاحية XRD, DRIFTS, Solid state DR UV/Vis, Solid state NMR, DFT Calculations, EXAFS, Lewis active sites, Designing active sites,
Design and control of Lewis acid sites in Sn-substituted microporous architectures
Monometallic and bimetallic tin-containing framework architectures have been prepared by hydrothermal methods. Structural and spectroscopic techniques were used to probe the nature of the solid-acid sites, at the molecular level, using a combination of XRD, DR UV-Vis, solid state MAS NMR (119Sn, 27Al and 31P) and XAFS. The nature and strength of the solid-acid sites were experimentally probed by FT-IR ... إقراء المزيد

2018-11-01 02:56:32 الكلمات المفتاحية In situ, Advanced spectroscopy, EXAFS, MoOx/Fe2O3, DRIFTS, Methanol oxidation,
In situ spectroscopic investigations of MoOx/Fe2O3 catalysts for the selective oxidation of methanol
Multicomponent oxide shell@core catalysts have been prepared, affording overlayers of MoO_x_ on Fe2O3. This design approach allows bulk characterization techniques, such as X-ray Absorption Fine Structure (XAFS), to provide surface sensitive information. Coupling this approach with _in situ_ methodologies provides insights during crucial catalytic processes. Calcination studies were followed by a combination of XAFS and Raman, and demonstrate that amorphous ... إقراء المزيد

2018-11-01 03:02:10 الكلمات المفتاحية Au-Pd supported catalysts, XAFS/DRIFTS, EXAFS, TEM,
Restructuring of AuPd Nanoparticles Studied by a Combined XAFS/DRIFTS Approach
The use of AuPd nanoparticles in catalysis is widespread, with the activity being attributed to their precise structural properties. We demonstrate the restructuring of AuPd nanoparticles under CO oxidation conditions using a combined XAFS/DRIFTS approach. The fresh catalyst exhibits PdO islands at the surface of the nanoparticles, which are reduced under reaction conditions, a process observed via both DRIFTS and ... إقراء المزيد