Catalysis Today, Vol.148, No.1-2, 6-11, 2009
Synthesis and properties of a zeolite LEV analogue from the system-Na2O-Al2O3-SiO2-N,N-dimethylpiperidine chloride-H2O
A new structure-directing agent (SDA) was firstly reported for the synthesis of a zeolite LEV analogue. N,N-dimethyl piperidine performed the SDA function, and induced the synthesis of products from a zeolite MOR with 12-ring channels to a zeolite LEV analogue with only 8-ring channels. The zeolite LEV analogue was synthesized from gels with initial compositions (5.0-6.0)Na2O-Al2O3-(10-200)SiO2-(4.0-8.0)N,N-dimethyl piperidine-400H(2)O at 150 degrees C. The Si-29 NMR spectra showed that the relative intensities of the first line at -115 ppm for low Si/Al ratios were lower than that at high Si/Al ratios. Varying ion exchanges led to different acidities in the zeolite LEV analogue, with the acidity of H-LEV-HCl higher than that of H-LEV-NH3 center dot H2O. Zeolite HAEV in hydration of propene showed a higher selectivity of 1-propanol. (C) 2009 Elsevier B.V. All rights reserved.