The location of fluoride and organic guests in 'as-made' pure silica zeolites FER and CHA

The structure determination of as-made silica zeolites CHA and FER prepared in the presence of fluoride ions has been accomplished using microcrystal X-ray diffraction at a synchrotron source. In both cases, the location of the fluoride ions has been determined. Fluoride ions are incorporated into small double six-ring cages in the CHA framework, and the organic guests have been located in the larger chabazite cages. In contrast to two previous single-crystal X-ray diffraction studies of as-made siliceous FER prepared in related ways fluoride ions are incorporated into the framework and are found occluded inside small cages in the structure.