2005
DOI: 10.1016/j.ssnmr.2005.02.004
|View full text |Cite
|
Sign up to set email alerts
|

Unambiguously distinguishing Si[3Si,1Al] and Si[3Si,1OH] stuctural units in zeolite by 1H/29Si/27Al triple resonance solid state NMR spectroscopy

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...
2
1

Citation Types

1
2
0

Year Published

2010
2010
2024
2024

Publication Types

Select...
6
2

Relationship

0
8

Authors

Journals

citations
Cited by 8 publications
(3 citation statements)
references
References 20 publications
1
2
0
Order By: Relevance
“…The bottom spectrum is acquired with the same spin–echo under the same MAS conditions, except for the application of 27 Al pulses during the echo evolution windows. This experimental approach, well-known in the literature as the spin–echo double resonance SEDOR or TRAPDOR experiment, has been used extensively to identify protons that are within a dipolar-coupling distance (2–6 Å) of an aluminum atom in inorganic oxides. Of the four labeled peaks in the bottom spectrum of Figure , only the Si–OH peak intensity is the same in both experiments, which is consistent with the known fact that those hydroxyl groups are not close to Al atoms. The very small decrease in the SiOH intensity is due to the loss of the 2.8 ppm extra-framework AlOH peak with which it overlaps.…”
Section: Resultssupporting
confidence: 64%
“…The bottom spectrum is acquired with the same spin–echo under the same MAS conditions, except for the application of 27 Al pulses during the echo evolution windows. This experimental approach, well-known in the literature as the spin–echo double resonance SEDOR or TRAPDOR experiment, has been used extensively to identify protons that are within a dipolar-coupling distance (2–6 Å) of an aluminum atom in inorganic oxides. Of the four labeled peaks in the bottom spectrum of Figure , only the Si–OH peak intensity is the same in both experiments, which is consistent with the known fact that those hydroxyl groups are not close to Al atoms. The very small decrease in the SiOH intensity is due to the loss of the 2.8 ppm extra-framework AlOH peak with which it overlaps.…”
Section: Resultssupporting
confidence: 64%
“…The top spectrum is acquired with a simple spin-echo pulse sequence and gives the same spectrum as those shown above that were acquired using a single pulse, while the bottom two spectra utilize the same spin-echo except for the application of 27 Al pulses during the echo evolution windows. This experimental approach, well-known in the literature as the spin-echo double resonance SEDOR or TRAPDOR experiment, has been used extensively to identify protons that are within a dipolar-coupling distance (2–6 Å) of an aluminum atom in inorganic oxides, as that coupling attenuates the refocused echo. Signals that arise from protons coupled to Al atoms decrease or are eliminated, while those that arise from species like the 2.0 ppm terminal silanol peak are not affected. Clearly, Figure shows that the 5–7 ppm peak is significantly attenuated in the bottom two spectra.…”
Section: Resultsmentioning
confidence: 99%
“…The latter is particularly important because the Si[3Si, 1Al] units are generally associated with the acidic SiOHAl groups, while the Si[3Si, 1OH] units correspond to nonacidic silanol groups in zeolite defects. Luo and co-workers 139 have shown how to apply the triple-resonance techniques based on the 1 H/ 27 Al/ 29 Si TRAPDOR-CP and 1 H/ 27 Al TRAPDOR pulse sequences. For example, the different peaks, observed in the 29 Si CP NMR spectra of materials MCM, can be distinguished and assigned by this triple-resonance NMR approach.…”
Section: Structural Features Of the Silica Lattice Bymentioning
confidence: 99%