scholarly journals Oxygen chemisorption on Cu(110): A structural determination by x-ray diffraction

1990 ◽  
Vol 41 (8) ◽  
pp. 5420-5423 ◽  
Author(s):  
R. Feidenhans’l ◽  
F. Grey ◽  
R. L. Johnson ◽  
S. G. J. Mochrie ◽  
J. Bohr ◽  
...  
Keyword(s):  
Structural Determination ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxygen Chemisorption

Hydrogen and Oxygen Chemisorptions and Titrations by Platinum on Zirconia Catalysts Reduced between 673 and 1273 K

1985 ◽  
Vol 2 (2) ◽  
pp. 55-68 ◽  
Author(s):  
L. Tournayan ◽  
A. Auroux ◽  
H. Charcosset ◽  
R. Szymanski
Keyword(s):  
Surface Composition ◽  
Pt Catalyst ◽  
Hydrogen Chemisorption ◽  
Alloy Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxygen Chemisorption ◽  
Alloy Particles ◽  
Frontal Method ◽  
The Mean

Some 10 wt % Pt supported on zirconia catalysts were investigated by hydrogen and oxygen chemisorptions and titrations by means of automated catharometric equipment (frontal method). Microcalorimetry was further used to determine the heats of oxygen chemisorption. The temperature of reduction by hydrogen, TR, was varied between 673 and 1273 K. At 673 K, the H and O coverages of Pt were about the same as for Pt supported on SiO2 (Euro Pt catalyst). The increase in TR from 673 to 873 K was accompanied by a strong decrease of the hydrogen to oxygen chemisorption ratio. It is proposed that this is due to Pt1– xZr x alloy formation, with small values of x (≤0·05). When TR was above 873 K, x determined by X-ray diffraction analysis increased up to 0·25. The hydrogen chemisorption is confined to Pt s, while the oxygen chemisorption takes place on Pt s and Zr sO x. The surface composition may be derived and is found twice as rich in Zr as the mean composition of the alloy particles.

A SURFACE ANOMALOUS DIFFRACTION STUDY OF THE Ni(100)(3×3)-(Cs+O) SYSTEM

1999 ◽  
Vol 06 (05) ◽  
pp. 847-850 ◽  
Author(s):  
A. G. NORRIS ◽  
C. A. LUCAS ◽  
R. McGRATH ◽  
F. SCHEDIN ◽  
G. THORNTON ◽  
...  
Keyword(s):  
Fractional Order ◽  
Anomalous Scattering ◽  
Nickel Surface ◽  
Structural Determination ◽  
Nickel Substrate ◽  
X Ray Diffraction ◽  
Diffraction Intensity ◽  
Surface Layers ◽  
X Ray ◽  
Intensity Measurements

Alkali metal coadsorption systems represent a step along the pathway from simple model adsorbate overlayers to more technologically relevant real systems. However, such is their complexity that very few systems have been structurally determined. Here we present a surface X-ray diffraction investigation of one of these systems, Ni (100)-(3×3)- (Cs+O) . Here a structural determination is particularly challenging due to the presence of three species in the surface layers and by the size of the unit cell. As a first step, anomalous scattering has been used to determine whether there is a contribution of the nickel substrate to the fractional order diffraction intensity. Measurements of the fractional order rods at 10 eV and 200 V below the nickel K edge (8333 eV) were used to probe the nickel contribution to the fractional order rods. It was found that the intensity of the scattering was unchanged, indicating that the fractional order peaks are caused by scattering from the coadsorbates only. This shows that the nickel surface layers are not changed by the adsorption and thus sets a useful constraint on the number of possible structures.

scholarly journals Structural Determination of the Epitaxial C60 Overlayer on the Pentacene Single Crystal by Grazing Incidence X-ray Diffraction

Hyomen Kagaku ◽  
2016 ◽  
Vol 37 (9) ◽  
pp. 429-434 ◽  
Author(s):  
Ryohei TSURUTA ◽  
Yuta MIZUNO ◽  
Takuya HOSOKAI ◽  
Tomoyuki KOGANEZAWA ◽  
Hisao ISHII ◽  
...  
Keyword(s):  
Single Crystal ◽  
Grazing Incidence ◽  
Structural Determination ◽  
X Ray Diffraction ◽  
X Ray

Visualizing changes of molecular conformation in the solid-state by a common structural determination technique: single crystal X-ray diffraction

2021 ◽  
Vol 5 (1) ◽  
pp. 341-346
Author(s):  
Jun Zhang ◽  
Haoke Zhang ◽  
Junkai Liu ◽  
Jacky Wing Yip Lam ◽  
Ben Zhong Tang
Keyword(s):  
Solid State ◽  
Single Crystal ◽  
Molecular Conformation ◽  
Vital Role ◽  
Structural Determination ◽  
X Ray Diffraction ◽  
X Ray ◽  
Advanced Technologies

Changes of molecular conformation in the solid state play a vital role in many advanced technologies.

scholarly journals Three-dimensional electron diffraction for porous crystalline materials: structural determination and beyond

2021 ◽  
Author(s):  
Zhehao Huang ◽  
Tom Willhammar ◽  
Xiaodong Zou
Keyword(s):  
Electron Diffraction ◽  
Three Dimensional ◽  
Structural Determination ◽  
New Materials ◽  
Dimensional Electron ◽  
X Ray Diffraction ◽  
Crystalline Materials ◽  
X Ray ◽  
Structural Details

Three-dimensional electron diffraction is a powerful tool for accurate structure determination of zeolite, MOF, and COF crystals that are too small for X-ray diffraction. By revealing the structural details, the properties of the materials can be understood, and new materials and applications can be designed.

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