Tame the Super Greenhouse Gas-Chf3 Via F/Cl Exchange Reaction over Partially Chlorinated Al-based Fluoride Catalysts

CHF3 is considered as one kind of super greenhouse gases with extremely high global warming potential which is the byproduct during the manufacture of HCFC-22 (CHClF2). Treatment CHF3 via F/Cl exchange reaction with CHCl3 forming CHCl2F and CHClF2 is a potential resource utilization route rather than high energy-demanding incineration. The results confirmed that the crystal structures of Al-based fluorides were important to the catalytic activity due to it affects the availabilities of the Lewis acid sites. Through the DFT calculation, it found that AlClxFy species acted as the active sites for the CHF3 conversion could decrease the energy barrier for the cleavage of C-F bonds. Furthermore, XPS analysis depicted that lower binding energy of Al-F was more likely to be partially chlorinated to formation AlClxFy species. Correspondingly,.-AlF3 showed the best catalytic performance for the CHF3 conversion (30%) as well as less coke deposition contributed by the suitable Lewis acidic intensity.