Charge matching between the occluded organic cations and zeolite framework as structure directing effect in zeolite synthesis

The charge matching effect has been found to be an important parameter driving the synthesis towards particular zeolite frameworks. This has been evidenced by isomorphous incorporation of Aluminium into the zeolite synthesis as well as by incorporation of fluoride anions at zeolite interstices. In both cases, negatively zeolite frameworks are developed and the resulting structure must provide enough space to locate the compensating organic cations. Therefore, this can be used by combining with the appropriate selection of organic polycations to direct the synthesis towards a particular structure, such as the formation of Ge-ITQ-24 materials.