scholarly journals Bulk phase behavior of lithium imide–metal nitride ammonia decomposition catalysts

2018 ◽  
Vol 20 (35) ◽  
pp. 22689-22697 ◽  
Author(s):  
Joshua W. Makepeace ◽  
Thomas J. Wood ◽  
Phillip L. Marks ◽  
Ronald I. Smith ◽  
Claire A. Murray ◽  
...  
Keyword(s):  
Phase Behavior ◽  
Powder Diffraction ◽  
Ammonia Decomposition ◽  
Bulk Phase ◽  
Metal Nitride ◽  
X Ray ◽  
Composite Catalysts ◽  
Production Of Hydrogen ◽  
Lithium Imide

Lithium imide is a promising new catalyst for the production of hydrogen from ammonia. This study reports the use of neutron and X-ray powder diffraction to investigate the presence of ternary nitrides in lithium-imide/metal nitride composite catalysts.

scholarly journals Ammonia decomposition catalysis using lithium–calcium imide

2016 ◽  
Vol 188 ◽  
pp. 525-544 ◽  
Author(s):  
Joshua W. Makepeace ◽  
Hazel M. A. Hunter ◽  
Thomas J. Wood ◽  
Ronald I. Smith ◽  
Claire A. Murray ◽  
...  
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Powder Diffraction ◽  
Light Metal ◽  
Reaction Mass ◽  
Ammonia Decomposition ◽  
The Other ◽  
Lithium Amide ◽  
Lithium Imide

Lithium–calcium imide is explored as a catalyst for the decomposition of ammonia. It shows the highest ammonia decomposition activity yet reported for a pure light metal amide or imide, comparable to lithium imide–amide at high temperature, with superior conversion observed at lower temperatures. Importantly, the post-reaction mass recovery of lithium–calcium imide is almost complete, indicating that it may be easier to contain than the other amide–imide catalysts reported to date. The basis of this improved recovery is that the catalyst is, at least partially, solid across the temperature range studied under ammonia flow. However, lithium–calcium imide itself is only stable at low and high temperatures under ammonia, with in situ powder diffraction showing the decomposition of the catalyst to lithium amide–imide and calcium imide at intermediate temperatures of 200–460 °C.

Phase behavior and extended phase scheme of static cocoa butter investigated with real-time X-ray powder diffraction

1999 ◽  
Vol 76 (6) ◽  
pp. 669-676 ◽  
Author(s):  
Kees van Malssen ◽  
Arjen van Langevelde ◽  
René Peschar ◽  
Henk Schenk
Keyword(s):  
Cocoa Butter ◽  
Phase Behavior ◽  
Real Time ◽  
Powder Diffraction ◽  
Extended Phase ◽  
X Ray

New horizons for the structural characterization of stainless steel slags by X-ray powder diffraction

2007 ◽  
Vol 2007 (suppl_26) ◽  
pp. 61-66 ◽  
Author(s):  
B. Peplinski ◽  
B. Adamczyk ◽  
G. Kley ◽  
K. Adam ◽  
F. Emmerling ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Powder Diffraction ◽  
Structural Characterization ◽  
X Ray ◽  
New Horizons

The evaluation of the kinetics of ordering processes in Ni1 + δSn (δ = 0.35, 0.50) by X-ray powder diffraction

2006 ◽  
Vol 2006 (suppl_23_2006) ◽  
pp. 351-356 ◽  
Author(s):  
A. Leineweber ◽  
E. J. Mittemeijer
Keyword(s):  
Powder Diffraction ◽  
X Ray ◽  
Kinetics Of

X-ray Structure Refinement and Vibrational Spectroscopy of Ca8Gd2 (PO4)6 O2

2013 ◽  
Vol 12 (10) ◽  
pp. 719-726
Author(s):  
R. Ayadi ◽  
Mohamed Boujelbene ◽  
T. Mhiri
Keyword(s):  
Solid State ◽  
General Formula ◽  
Vibrational Spectroscopy ◽  
Powder Diffraction ◽  
Infrared Spectra ◽  
Solid State Reaction ◽  
Structure Refinement ◽  
Unit Cell ◽  
Cell Group ◽  
X Ray

The present paper is interested in the study of compounds from the apatite family with the general formula Ca10 (PO4)6A2. It particularly brings to light the exploitation of the distinctive stereochemistries of two Ca positions in apatite. In fact, Gd-Bearing oxyapatiteCa8 Gd2 (PO4)6O2 has been synthesized by solid state reaction and characterized by X-ray powder diffraction. The site occupancies of substituents is0.3333 in Gd and 0.3333 for Ca in the Ca(1) position and 0. 5 for Gd in the Ca (2) position.  Besides, the observed frequencies in the Raman and infrared spectra were explained and discussed on the basis of unit-cell group analyses.

Monitoring Polymer-Assisted Mechanochemical Cocrystallisation Through in Situ X-Ray Powder Diffraction

2020 ◽  
Author(s):  
Luzia S. Germann ◽  
Sebastian T. Emmerling ◽  
Manuel Wilke ◽  
Robert E. Dinnebier ◽  
Mariarosa Moneghini ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Powder Diffraction ◽  
Reaction Rate ◽  
Polymer Additives ◽  
Time Resolved ◽  
X Ray

Time-resolved mechanochemical cocrystallisation studies have so-far focused solely on neat and liquid-assisted grinding. Here, we report the monitoring of polymer-assisted grinding reactions using <i>in situ</i> X-ray powder diffraction, revealing that reaction rate is almost double compared to neat grinding and independent of the molecular weight and amount of used polymer additives.<br>

Crystal Transition and Drug-excipient Compatibility of Clarithromycin in Sustained Release Tablets

2020 ◽  
Vol 16 (7) ◽  
pp. 950-959
Author(s):  
Yu Li ◽  
Xiangwen Kong ◽  
Fan Hu
Keyword(s):  
Sustained Release ◽  
Powder Diffraction ◽  
Magnesium Stearate ◽  
Influential Factor ◽  
High Concentration ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Sustained Release Tablets ◽  
Crystal Transition ◽  
Excipient Compatibility

Background: Clarithromycin is widely used for infections of helicobacter pylori. Clarithromycin belongs to polymorphic drug. Crystalline state changes of clarithromycin in sustained release tablets were found. Objective: The aim of this study was to find the influential factor of the crystal transition of clarithromycin in preparation process of sustained-release tablets and to investigate the possible interactions between the clarithromycin and pharmaceutical excipients. Methods and Results: The crystal transition of active pharmaceuticals ingredients from form II to form I in portion in clarithromycin sustained release tablets were confirmed by x-ray powder diffraction. The techniques including differential scanning calorimetry and infrared spectroscopy, x-ray powder diffraction were used for assessing the compatibility between clarithromycin and several excipients as magnesium stearate, lactose, sodium carboxymethyl cellulose, polyvinyl-pyrrolidone K-30 and microcrystalline cellulose. All of these methods showed compatibilities between clarithromycin and the selected excipients. Alcohol prescription simulation was also done, which showed incompatibility between clarithromycin and concentration alcohol. Conclusion: It was confirmed that the reason for the incompatibility of clarithromycin with high concentration of alcohol was crystal transition.

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