A Silicogermanate with a Si : Ge Ratio ≥ 2—an MFI Zeolite of Novel Composition

A pure Ge‐MFI zeolite is expected to be difficult to synthesize . This is the conclusion drawn from a study on the possibilities and effects of Si/Ge exchange in Si‐MFI zeolites. When for example, the mixture GeCl 4 SiO 2 HF0.5 Pr 4 NBr8 CH 3 NH 2 35 H 2 O is heated to 180°C for 15 h there results a solid with MFI structure, which, after calcination, has the composition Si 63 Ge 33 O 192 . The unusually high Ge content surpasses all previously observed degrees of substitution in MFI zeolites.