Total Scattering Debye Function Analysis: Effective Approach for Structural Studies of Supported MoS2-Based Hydrotreating Catalysts

2020 ◽  
Vol 59 (23) ◽  
pp. 10914-10922
Author(s):  
Vera P. Pakharukova ◽  
Dmitry A. Yatsenko ◽  
Evgeny Yu Gerasimov ◽  
Evgenia Vlasova ◽  
Galina A. Bukhtiyarova ◽  
...  
Keyword(s):  
Function Analysis ◽  
Structural Studies ◽  
Debye Function ◽  
Total Scattering ◽  
Hydrotreating Catalysts

scholarly journals A total scattering Debye function analysis study of faulted Pt nanocrystals embedded in a porous matrix

2016 ◽  
Vol 72 (6) ◽  
pp. 632-644 ◽  
Author(s):  
Federica Bertolotti ◽  
Daniele Moscheni ◽  
Andrea Migliori ◽  
Stefano Zacchini ◽  
Antonio Cervellino ◽  
...  
Keyword(s):  
Function Analysis ◽  
Statistical Significance ◽  
Porous Matrix ◽  
Silica Matrix ◽  
Scattering Data ◽  
Surface Relaxation ◽  
Debye Function ◽  
Total Scattering ◽  
Pt Nanoclusters ◽  
Relaxation Effects

Faulted face-centred cubic platinum nanocrystals, grown within a nanoporous silica matrix, have been extensively characterized by the Debye function analysis method applied to wide-angle synchrotron X-ray total scattering data. A method for building databases of sampled interatomic distances of weakly faulted materials is proposed, maintaining statistical significance and allowing complete populations of differently sized and shaped nanocrystals to be used within theDEBUSSYapproach. This study suggests that anisotropic Pt nanoclusters are formed in the presence of a shape-directing (templating) agent, and tentatively describes the effects of post-synthetic temperature treatments on fault probability, size, shape and dispersion of the nanocrystal populations. Surface relaxation effects are also observed in the smallest particles.

scholarly journals Total-scattering pair-distribution function analysis of zinc from high-energy synchrotron data

2019 ◽  
Vol 33 (33) ◽  
pp. 1950410 ◽  
Author(s):  
Ahmad S. Masadeh ◽  
Moneeb T. M. Shatnawi ◽  
Ghosoun Adawi ◽  
Yang Ren
Keyword(s):  
Crystal Structure ◽  
Distribution Function ◽  
Pair Distribution Function ◽  
Function Analysis ◽  
High Energy ◽  
Ambient Conditions ◽  
Total Scattering ◽  
X Ray ◽  
Zinc Metal ◽  
Pdf Analysis

The crystal structure of zinc metal deviates from the ideal hexagonal close packing structure by a significantly increased axial ratio (c/a). The local atomic structure of zinc metal is investigated using the total scattering atomic pair distribution function (PDF) analysis based on X-ray powder diffraction data collected at ambient conditions. The X-ray total scattering PDF analysis confirms that the crystal structure of zinc can be described in terms of wurtzite structure, but with an anomalously atomic displacement parameters [Formula: see text], indicating a significant displacement disorder along the [Formula: see text]-axis. For the long [Formula: see text]-range PDF refinements, the thermal motion of zinc shows a notable anisotropy as expressed by the ratio [Formula: see text]/[Formula: see text] of 2.5 at ambient conditions. This average distortion level along the [Formula: see text]-axis, was not reflected locally for the features below 5.0 Å as it fits the high [Formula: see text] region. Based on PDF refinements over different [Formula: see text]-ranges, we measure an interesting increase of the [Formula: see text] value with decreasing the [Formula: see text]-range of the refinement. This suggests that the local structure features in zinc metal differ from the average structure ones.

scholarly journals A review of Debye Function Analysis

2013 ◽  
Vol 28 (S2) ◽  
pp. S2-S10 ◽  
Author(s):  
Kenneth R. Beyerlein
Keyword(s):  
Diffraction Pattern ◽  
Powder Diffraction ◽  
Function Analysis ◽  
Reciprocal Space ◽  
Spherical Particles ◽  
Complete Agreement ◽  
Line Profiles ◽  
Debye Function

The employment of the Debye function to model line profiles in the powder diffraction pattern from small crystallites is briefly reviewed. It is also demonstrated that for the case of very small spherical particles, it is necessary to average patterns from multiple constructions of the particle to have complete agreement with reciprocal space models. In doing so it is demonstrated that the technique of Debye function analysis is best suited for systems with only a few possible atomic arrangements.

scholarly journals DEBUSSY 2.0: the new release of a Debye user system for nanocrystalline and/or disordered materials

2015 ◽  
Vol 48 (6) ◽  
pp. 2026-2032 ◽  
Author(s):  
Antonio Cervellino ◽  
Ruggero Frison ◽  
Federica Bertolotti ◽  
Antonietta Guagliardi
Keyword(s):  
Function Analysis ◽  
Computational Modelling ◽  
Site Occupancy ◽  
Group Symmetry ◽  
Model Parameters ◽  
General Strategy ◽  
Debye Function ◽  
Shape Information ◽  
Size Dependent ◽  
A Chain

The new release ofDEBUSSYis introduced, a free open-source package devoted to the application of the Debye function analysis of powder diffraction data from nanocrystalline, defective and/or nonperiodic materials. The general strategy of the suite remains unchanged, following a two-step approach managed by theCLAUDEandDEBUSSYprograms, respectively. The first step essentially consists in generating a database where structural, size and shape information on a nanocrystal population is stored; the second step consists in the calculation, through the Debye scattering equation, of the total diffraction pattern using the previously generated database and a set of model parameters provided by the user and then optimized by the program. The novelties lie in the computational, modelling and graphical levels, and several new programs and features have been added. Among these are a new general comprehensive input file format (.ddb) for the database generation, the automatic management of the space-group symmetry and .cif file, new nanocrystal shapes, size-dependent site occupancy factors and thermal parameters for each atomic species, new lattice expansion functions, and a newly developed algorithm for calculating the standard errors of the optimized parameters. TheCLAUDEsuite also includes a program for calculation of the pair distribution function. Last but not least, a graphical user interface, which makes it easier to edit input files, execute the programs of the suite in a chain-like way, and plot the results in an automatic or custom manner, is provided.

Structural Analysis of Au/TiO2Catalysts by Debye Function Analysis

1999 ◽  
Vol 183 (1) ◽  
pp. 24-31 ◽  
Author(s):  
D.A.H. Cunningham ◽  
W. Vogel ◽  
R.M.Torres Sanchez ◽  
K. Tanaka ◽  
M. Haruta
Keyword(s):  
Structural Analysis ◽  
Function Analysis ◽  
Debye Function

scholarly journals Exploring the origins of crystallisation kinetics in hierarchical materials using in situ X-ray diffraction and pair distribution function analysis

2020 ◽  
Vol 22 (34) ◽  
pp. 18860-18867 ◽  
Author(s):  
Matthew E. Potter ◽  
Mark E. Light ◽  
Daniel J. M. Irving ◽  
Alice E. Oakley ◽  
Stephanie Chapman ◽  
...  
Keyword(s):  
Distribution Function ◽  
Pair Distribution Function ◽  
Function Analysis ◽  
X Ray Diffraction ◽  
Crystallisation Kinetics ◽  
Total Scattering ◽  
Hierarchically Porous ◽  
X Ray ◽  
Scattering Measurements

Novel in situ synchrotron total scattering measurements probe the assembly of primary building units into templated hierarchically porous aluminophosphate catalysts, providing unique insights to understanding crystallisation kinetics.

Sign in / Sign up

Export Citation Format

Share Document