Research Institute of Petroleum Industry (N.I.O.C.), Catalysis Research Center, P.O. Box 18745-4163, Tehran, I.R. IRAN
A new polymorph crystalline silica composition having uniform pore dimensions were synthesized by calcining a crystalline hydrated alkyl-ammonium silicate. The pore dimensions approximately were 6 angstrom for silicalite-1 and 11 angstrom for silicalite-2 units. The silicalite-1 was prepared hydrothermally at a pH of about 10 from a reaction mixture consist of water, amorphous silica and a quaternary ammonium compound. Domestic water glass was ion-exchanged to produce silicasol. In this work we also investigated the influence of alkalinity percent in the starting gel mixture on the crystal shape and size.
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