A high-surface-area (190 m2/g) amorphous aluminum trifluoride material ("plasma-AlF3") was synthesized by plasma decomposition of zeolite, and its structural and reactivity properties were investigated. High-resolution transmission electron microscopy of plasma-AlF3 indicates morphological features on the nanometer-scale, whereas temperature-programmed X-ray diffraction is used to determine the phase-transition temperatures of plasma-AlF3 to β- and α-AlF3. Halogen-exchange reactivity is studied by temperature-programmed reaction (TPR) techniques using the dismutation of CCl2F2 as a model reaction. Plasma-AlF3 is found to possess an unexpected low-temperature (>315°C) activity not observed with the well-known halogen-exchange catalyst β-AlF3. Supporting TPR studies on aluminum trifluoride hydrates are performed to correlate this new activity with an amorphous AlF3 structure, and a simple Lewis acid model is presented to explain the reactivity data.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Materials Chemistry