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.