Convenient synthesis of large mordenite crystals

Large mordenite (MOR) zeolite crystals with 60-85 mu m in length were easily obtained from the low-water content system without any additives. From nitrogen adsorption, it was found that the as-synthesized MOR(Na+MOR) zeolites obtained with Al(NO3)(3), Al-2(SO4)(3) and AlCl3 as an At source are the small port type zeolite, whereas the MOR zeolite obtained with Al(OH)3 is the large port type zeolite. However, Li+ cation-exchange rendered the small port type MOR zeolite into the large port one. When NH4F was employed as a fluoride source and added into the starting synthesis gel, all of MOR zeolites obtained were the large port type zeolite regardless of At source. The addition of NH4F did not affect the crystal size very much. (c) 2006 Elsevier B.V. All rights reserved.