| 摘要 |
The preparation of high-silicon zeolites of the pentasil family has hitherto been possible only with the addition of organic structure-controlling compounds to the synthesis mixture. These processes have, however, serious disadvantages which preclude environmentally sound production on a large industrial scale. Preparation processes in which it was possible to dispense with the use of organic substances lead only very slowly to the desired product, and the emergence of undesired secondary phases cannot be precluded. A process is to be developed in which the disadvantages of the known processes are avoided. The process is characterised in that the catalyst or catalyst component used is a synthetic crystalline aluminosilicate of the chemical composition 0-3M2O : Al2O3 : 15-40 SiO2 : 0-40 H2O, M being a metal cation, and the crystalline aluminosilicate showing in its X-ray diffractogram at least the X-ray reflections which correspond to the d values listed in Table 1, and the SiO2/Al2O3 molar ratio thereof at the crystallite surface being greater than or equal to the molar SiO2/Al2O3 ratio in the crystal interior, and the <29>silicon solid MAS nuclear magnetic resonance spectrum thereof showing absorption bands at about -100, -106, -112 and -116 ppm relative to tetramethylsilane as standard. The process is used for the catalytic conversion of hydrocarbons. Table 1 <IMAGE> |
