PROPERTIES OF TI-BETA ZEOLITES SYNTHESIZED BY DRY-GEL CONVERSION AND HYDROTHERMAL METHODS

The large-pore beta zeolite containing Ti has been synthesized in the presence of alkali cations (Na+) by a dry-gel conversion (DGC) techniq ue using tetraethylammonium hydroxide (TEAOH) as a structure-directing agent. The obtained Ti-beta zeolites were compared with hydrothermall y synthesized (HTS) Ti-beta. It was found that Ti-beta-DGC samples ads orbed less water (12-13 wt %) than Ti-beta-HTS (19 wt %), indicating t hat Ti-beta-DCC is more hydrophobic than Ti-beta-HTS. We propose that this leads to a higher activity for the former in the oxidation of cyc lohexane. Upon being washed with H2SO4, the turnover number (TON) of D GC samples slightly increased for the oxidation of cyclohexane. DGC an d HTS samples demonstrated no significant difference in the activity f or oxidation reactions of unsaturated alcohols and C-6-C-8 cyclic alco hols.