17O DOR and other solid-state NMR studies concerning the basic properties of zeolites LSX

We demonstrate complementary ¹H, ¹⁷O, ²⁷Al and ²⁹Si measurements for basic low-silica-X zeolites, which were unloaded and pyrrole and formic acid-loaded. It was found that the acid–base-system is not stabile, if the loading exceeds one pyrrole molecule or two formic acid molecules per supercage.¹⁷O DOR NMR spectra exhibit at least four lines, which are broadened by a distribution of chemical shifts in a similar extend as the ²⁹Si MAS NMR spectra are broadened by distribution of Si–O–Al angles. A strong cation influence upon ¹⁷O shifts was observed. But there was no strong influence of the acid molecules on the mean value of the ¹⁷O shift of the spectra.