Investigation of active sites using solid state 27Al and 31P MAS NMR in Ceramic amorphous aluminophosphate materials prepared from different potassium salts of phosphate for the synthesis of Diphenyl Urea derivatives

2021 ◽  
pp. 110087
Author(s):  
N. Harish ◽  
N. Kathyayini ◽  
Bindhu Baby ◽  
N. Nagaraju
Keyword(s):  
Solid State ◽  
Active Sites ◽  
Mas Nmr ◽  
Potassium Salts ◽  
Urea Derivatives ◽  
31P Mas Nmr

scholarly journals Zeolite-based catalysts for the removal of trace olefins from aromatic streams

2020 ◽  
Vol 10 (3) ◽  
pp. 107-114
Author(s):  
Jakkidi Krishna Reddy ◽  
Shruti Lad ◽  
Kshudiram Mantri ◽  
Jagannath Das ◽  
Ganesan Raman ◽  
...  
Keyword(s):  
Solid State ◽  
Surface Area ◽  
Active Sites ◽  
External Surface ◽  
Mas Nmr ◽  
Fast Diffusion ◽  
External Surface Area ◽  
Olefin Conversion ◽  
The Family ◽  
Pore Clogging

Abstract Removal of trace olefins from aromatic liquids was investigated on UZM-8 and MCM-22, which are the family of MWW zeolites. Both these zeolites were synthesized with similar Si/Al ratio and characterized by various techniques such as XRD, SEM, ICP, N2 adsorption, Ammonia TPD and solid-state MAS-NMR. Olefin conversion activity over UZM-8 was found to be significantly higher than that of MCM-22. In addition to this, deactivation of UZM-8 was slower than the MCM-22. UZM-8 with irregular stacking of MWW layers possess high external surface area and exposes more number of active sites to the reactant molecules. Mesopores generated due to the disordered layers of UZM-8 allows the fast diffusion of the substrate molecules in which pore clogging does not occur, thus making it more active and slow deactivation than that of MCM-22. Graphic abstract

Influence of the CaO/MgO ratio on the structure of phase-separated glasses: a solid state 29Si and 31P MAS NMR study

2000 ◽  
Vol 265 (3) ◽  
pp. 221-229 ◽  
Author(s):  
J.M Oliveira ◽  
R.N Correia ◽  
M.H Fernandes ◽  
J Rocha
Keyword(s):  
Solid State ◽  
Mas Nmr ◽  
Nmr Study ◽  
31P Mas Nmr

The crystal structure of BaPO3F revisited – a combined X-ray diffraction and solid-state 19F, 31P MAS NMR study

2013 ◽  
Vol 42 (32) ◽  
pp. 11672 ◽  
Author(s):  
Berthold Stöger ◽  
Matthias Weil ◽  
Jørgen Skibsted
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Mas Nmr ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nmr Study ◽  
31P Mas Nmr

Solid State NMR Studies of Ionically Conductive Non-Oxide Chalcogenide Glasses

1988 ◽  
Vol 135 ◽  
Author(s):  
Hellmut Eckert ◽  
Zhengming Zhang ◽  
J. H. Kennedy
Keyword(s):  
Solid State ◽  
Chalcogenide Glasses ◽  
Structural Information ◽  
Microphase Separation ◽  
Mas Nmr ◽  
Oxide Glasses ◽  
Nmr Studies ◽  
Rare Isotope ◽  
31P Mas Nmr ◽  
Lithium Nmr

AbstractThe utility of 29Si, 31 p, and 6.7 Li MAS-NMR at 7.05 T to provide structural information in non-oxide chalcogenide glasses is discussed in connection with experimental results obtained on the systems Li2 S-SiS2, Li2 S-SiS2 -P2S5, and Li2 S-P2 S5-B2 S329Si MAS-NMR data indicate that the principles governing glass formation in these systems are fundamentally different from those applicable to stoichiometry-analog oxide glasses. 31p MAS-NMR can be used to identify microphase-separation in glasses containing two network former constituents. The use of the rare isotope 6 Li instead of 7 Li offers the advantage of significantly improved spectroscopic resolution, enabling the presentation of the first comprehensive lithium NMR chemical shift scale in the solid state.

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