New synthesis technique of supported ZSM-5 using organo-alumino-silicic gels

Synthesis of silicalite-1 from organo-silicic gels

“…For the latter, the degree of transformation of the mixed gel of RHA and clinoptilolite [3] into ZSM-5 is high. The external surface area is of the same order of magnitude in silicalite-1 as in ZSM-5.…”

“…The properties of RHA and of the silica gels derived from it have been described separately [3]. The silica derived from the hydrolysis of the depolymerized RHA in water, has a BET surface area of 237 m 2 /g and a pore volume circa 0.46 cc/g.…”

“…The procedure to obtain the C/Si ratio in the gel, excluding the carbon of the glycerol solvent has been described previously [7]. For instance, the C/Si ratio was ≈1 in the gel obtained from RHA before hydrolysis [3].…”

“…This gel was formed by reacting a mechanical mixture of RHA and of natural clinoptilolite (working as aluminum donor), with glycerol during 2 h at 200 • C [3]. It was hydrolyzed by a solution of tetra-propylammonium hydroxide (TPAOH) and then aged for two days at 135 • C in a stainless steel autoclave.…”

Crystallization of faujasite Y from seeds dispersed on mesoporous materials

“…Several two-step syntheses have been reported in the literature [3][4][5][6][7][8][9][10][11][12]. Kaliaguine et al [4] have prepared a series of materials, called UL-ZSM-5, exhibiting micro-and mesoporosity from a mesoporous worm-like alumino-silicate precursor.…”