Growth of hydrothermally stable meso-porous silica structure interconnected around micro-porous zeolite crystals

The growth of hydrothermally stable ordered meso-porous silica with M41S type structure interconnected around zeolite crystals was achieved from seeds normally nucleating the crystallization of micro-porous zeolite. The solid state NMR and FT-IR showed species like Si(OSi)3OH and Si(OSi)2(OH)2 (or Q3 and Q2 sites, respectively) are formed during first hydrothermal treatment with surfactant and NaOH. These species and surface silanol group of zeolite crystal condense to give meso-porous silica structure interconnected around zeolite crystal during re-crystallization at lower pH. Resulting meso-micro-porous hybrid material is found to be highly active, selective and stable in the synthesis of 2-(phenylamino) ethanol from aniline and ethylene carbonate compare to parent ZSM-5 and pure MCM-41.

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► Hydrothermally stable meso-porous silica interconnected around zeolite crystals.
► Q3 and Q2 sites are formed by hydrothermal treatment with surfactant and NaOH.
► Q3 and Q2 species condense to form meso-porous silica around zeolite crystal.
► Material formed is highly active, selective and stable in synthesis of 2-(phenylamino) ethanol.