화학공학소재연구정보센터
Journal of Physical Chemistry B, Vol.102, No.37, 7126-7131, 1998
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) technique using tetraethylammonium hydroxide (TEAOH) as a structure-directing agent. The obtained Ti-beta zeolites were compared with hydrothermally synthesized (HTS) Ti-beta. It was found that Ti-beta-DGC samples adsorbed less water (12-13 wt %) than Ti-beta-HTS (19 wt %), indicating that 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 cyclohexane. Upon being washed with H2SO4, the turnover number (TON) of DGC samples slightly increased for the oxidation of cyclohexane. DGC and HTS samples demonstrated no significant difference in the activity for oxidation reactions of unsaturated alcohols and C-6-C-8 cyclic alcohols.