Abstract

The optimum crystallization conditions for the transformation of kanemite into silicalite 1 have been determined by X-ray powder diffraction, thermal analysis and ²⁹Si NMR spectroscopy. The synthesis of silicalite 1 was favored by the use of a TPAOH template, in preference to a TPABr template, highly basic conditions during stirring of the suspension at 70 °C and the adjustment of the pH to 8.5 after stirring. The more the layered structure of kanemite disintegrated after the cation exchange reaction, the higher the amount of incorporated template and the higher the crystallinity of silicalite 1 after the solid-state transformation. The dissolution process that occurs during the cation exchange reaction with short-chain alkylammonium cations was different from that which occurs in the case of long-chain alkylammonium cations which are used for the synthesis of mesoporous materials.