A continuous and dense NaA zeolite membrane was synthesized by microwave heating method while employing a multi-step seeding LTA zeolite with the average size of 120 tun. The gas H-2/N-2 mixture separating results indicated that the mixture selectivity increased with increasing of synthesis times. In addition, selectivity of the three-step synthesis was higher than the value(3.74) expected from Kundsen diffusion
