I’m working on a catalyst SAPO which has a zeotype structure with the molar composition 0.40SiO2: A12O3: 0.90P2O5: 1.7iPr 2 EtN: 50H2O. I need to use Si NMR to study the incorporation of Si into the sapo-18 framework. I don't have access to solid-state NMR. I’m wondering whether it is possible to characterize the solid catalyst of sapo-18 by a liquid-state NMR? If it’s possible, what kind of solvents can I use?
Unfortunately you need solid-state 29Si NMR for that which is not the answer you wanted.
It is impossible to measure the zeolite sample with Liquid NMR. The MAS-Solid-29Si NMR is the only method to distinguish the different type of Si framework position.
Liquid phase NMR will give you huge line widths for almost all solids, so as John and Jiuxing it will be very unlikely to give you any info - would IR help? P-O is usually at above 1200 cm-1 and Al-O below 1000cm-1, so any Si-O should appear between the two. You'd need an ALPO as comparison to help with the analysis though, and the level of information would be less than you might get with solid 29Si (but maybe still useful?).
Yes, it is but only by using a special high-temperature NMR probe developed by us.
Signals are observable only when atoms or nuclei are moving or fluctuation in positions and/or orientations. These requirements are met at high temperatuers close to the melting point or higher tha that.
u can find some clue from following book, liquid Si NMR possible but u have to design ur own method and study before calcination to final catalyst
High-resolution solid-state NMR of silicates and zeolites
Author: Günter Engelhardt; Dieter Michel
Publisher: Chichester [West Sussex] ; New York : Wiley, ©1987.
Probably, my previous answer was not very useful for you unless the special high-temperature (up to 200 or more degree C required for the melting) probe is available. A new low cost experiment can be proposed with some extremely new idea. It would be to combine the Brownian motion of small enough size particles for the relaxation enhancement and some good common solution NMR spectrometer. Some broadening may be unavoidable but you may be able to gest some signals if you grind up your powder samle into sufficiently small-sized fine grains. You can try a cheap solvent for the fine powder suspension solution. The sensitivity of the naturally abundant NMR active element would not be very high. Thus the professional machine tuning and a long-time accumulation would be necessary. I am not together with you in your place, so I am not sure to what extent you can be successful. Actually, some trial and error would be needed. Be patient becausse of just the long-time labor cost for the special unusual sample preparation!
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