A novel method for preparation of silicalite-1 zeolite membrane in vapor phase

A silicalite-l zeolite membrane was in situ crystallized from a layer of si lica species prepared by a novel method of low temperature chemical vapor d eposition (LTCVD) on a porous cordierite substrate. XRD patterns show that the membrane consists of MFI type zeolite crystals. The investigation with SEM indicats that the membrane is about 50 mum thick, and covered with well -intergrowth MFI zeolite crystals of about 10 mum in size. The EDX analysis confirms that the membrane is composed of silica in the absence of Al, ind icating high silica MFI(Silicalite-l) zeolite grown on the support. The rat io of pure gas permeation is 296 for H-2/iso-butane and 13. 7 for n/iso-but ane at room temperature respectively, confirming that the membrane synthesi zed on the support of cordierite is high quality without pinhole.