A Study of Silver Species on Silver-Exchanged ETS-10 and Mordenite by XRD, SEM and Solid-State 109Ag, 29Si and 27Al NMR Spectroscopy

2012 ◽  
Vol 12 (8) ◽  
pp. 6420-6427 ◽  
Author(s):  
Yan Liu ◽  
Fu Chen ◽  
Roderick E. Wasylishen ◽  
Zhenghe Xu ◽  
James Sawada ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
27Al Nmr ◽  
27Al Nmr Spectroscopy

Aluminium coordination and structural disorder in halloysite and kaolinite by 27Al NMR spectroscopy

Clay Minerals ◽  
1994 ◽  
Vol 29 (3) ◽  
pp. 305-312 ◽  
Author(s):  
R.H. Newman ◽  
C.W. Childs ◽  
G.J. Churchman
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
High Field ◽  
Low Frequency ◽  
Crystallinity Index ◽  
Structural Disorder ◽  
Interlayer Water ◽  
27Al Nmr ◽  
Octahedral Sheet ◽  
27Al Nmr Spectroscopy

AbstractIt has been suggested that interlayer water in halloysite is due to the presence of hydrated cations that balance the negative layer charge produced by Al for Si substitution. To find evidence of 4-coordinate Al (Al(IV)), we investigated six halloysites and two kaolinites using ‘high-field’ and ‘medium-field’ solid-state 27Al MAS NMR spectroscopy. We found Al(IV) in both kaolinite and five halloysite samples, but the contents are all <1% and provide no basis for distinguishing between kaolinite and halloysite. Therefore, the presence of interlayer water in halloysite cannot be attributed to Al for Si substitution. There are, however, signals, tentatively assigned to A1(V), present in the kaolinite spectra but not in the halloysite spectra. The shapes of the low-frequency ‘tails’ of Al(VI) signals in medium-field NMR vary from sample to sample. We interpret this variation in terms of a ‘crystallinity index’. Disorder in kaolinite appears to be primarily the result of Al-vacancy displacements in the octahedral sheet. The NMR crystallinity indices correlate with those from IRS and DTA but not with those from XRD.

Probing the Dynamics of Layered Double Hydroxides by Solid-State 27Al NMR Spectroscopy

2017 ◽  
Vol 121 (13) ◽  
pp. 7276-7281 ◽  
Author(s):  
Arnaud Di Bitetto ◽  
Erwan André ◽  
Cédric Carteret ◽  
Pierrick Durand ◽  
Gwendal Kervern
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Layered Double Hydroxides ◽  
27Al Nmr ◽  
27Al Nmr Spectroscopy ◽  
Double Hydroxides

scholarly journals Reconsideration on Al Coordination in CaO–SiO2–Al2O3–(R2O or RO) Glasses by Using High Field Solid-State 27Al NMR Spectroscopy

2011 ◽  
Vol 51 (2) ◽  
pp. 333-335 ◽  
Author(s):  
Sohei Sukenaga ◽  
Tetsuya Nagahisa ◽  
Koji Kanehashi ◽  
Noritaka Saito ◽  
Kunihiko Nakashima
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
High Field ◽  
27Al Nmr ◽  
27Al Nmr Spectroscopy

27Al NMR spectroscopy at 104.2 MHz

1981 ◽  
Vol 44 (3) ◽  
pp. 584-589 ◽  
Author(s):  
J.W Akitt ◽  
Brian E Mann
Keyword(s):  
Nmr Spectroscopy ◽  
27Al Nmr ◽  
27Al Nmr Spectroscopy

Application of the 27Al NMR spectroscopy to studies of mechanisms of cyclic esters polymerization

Polimery ◽  
2007 ◽  
Vol 52 (10) ◽  
pp. 722-729 ◽  
Author(s):  
MARCIN FLORCZAK ◽  
ADAM KOWALSKI ◽  
JAN LIBISZOWSKI ◽  
KATARZYNA MAJERSKA ◽  
ANDRZEJ DUDA
Keyword(s):  
Nmr Spectroscopy ◽  
27Al Nmr ◽  
Cyclic Esters ◽  
27Al Nmr Spectroscopy

15 T, 4.2 K field-swept 27Al NMR spectroscopy

1994 ◽  
Vol 221 (1-2) ◽  
pp. 65-67 ◽  
Author(s):  
Xiao Wu ◽  
Eric A. Juban ◽  
Leslie G. Butler
Keyword(s):  
Nmr Spectroscopy ◽  
27Al Nmr ◽  
27Al Nmr Spectroscopy

An Investigation of AlCl3 Solutions in Ethers by 27Al NMR Spectroscopy

1982 ◽  
Vol 37 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Heinrich Nöth ◽  
Robert Rurländer ◽  
Peter Wolfgardt
Keyword(s):  
Nmr Spectroscopy ◽  
Donor Atom ◽  
Dilute Solutions ◽  
27Al Nmr ◽  
Nmr Studies ◽  
27Al Nmr Spectroscopy ◽  
Oxygen Donor ◽  
Tetrahedral Environment ◽  
Peak Areas ◽  
High Concentrations

Abstract27Al NMR studies of AlCl3 solutions in diethyl ether reveal the presence of AlCl4 at high concentrations. This ion can also be recognized besides AlCl3·OR2 at low temperature in dilute solutions, while at 25 °C a single signal is observed, which represents the average of all species in solution. More extensive dissociation of AlCl3 results in tetrahydrofuran. The main species in equilibrium with one another are AlCl3·2THF, AlCl-4 and AlCl2(THF)+2.Nearly quantitative dissociation to yield AlCl-4 and [AlClL5]2+ occurs in dilute solutions of AlCl3 in monoglyme (L reprents one oxygen donor atom); at higher concentration an adduct AlCl3·L with Al in a tetrahedral environment is also present. This trend towards extensive dissociation is also observed in the solutions of AlCl3 in diglyme and triglyme. Relative peak areas are in agreement with the formation of a 1:1 electrolyte [AlCl2L4]+AlCl-4 in diglyme, whereas additional dissociation into [AlClL5]2+ and AlCl-4 occurs in triglyme.

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