Abstract
The synthesis of mesoporous aluminum-silicate analogues to FSM-16 (Al-FSM) was reported. Mixtures containing various component of water glass, Al (NO3) 3 and NaOH were used as starting materials. The reactant was calcined at 973K (step 1). The resulting material was suspended in water for 3 hours to exchange Na+ and then dried (step 2). The obtained material was suspended in the hexadecyltrimethylammonium chloride aqueous solution to form a complex of layered silicate and surfactant (step 3). The obtained complex was calcined to decompose the surfactant and to obtain Al-FSM-16 (step 4). In both steps 1 and 2, layered silicates of various types were formed in the products. When tetrahedral Al sites were formed in either step 1 and step 2, it clearly showed that the Al ions in the products were incorporated into the frame of FSM-16. On the other hand, the absence of tetrahedral Al formation gave a significant amount of octahedral Al in addition to tetrahedral Al in the Al-FSM samples. corresponding The formation of tetrahedral Al in step 1 or step 2 therefore plays an important role incorporating Al into the framework of FSM-16. The Al content in Al-FSM samples increased with a corresponding increase of Al content in the starting material. The FT-IR, 27Al and 29Si MAS NMR results also suggest that Al is incorporated in the framework of FSM-16.
