Conversion of fluoroform to CHCl3 and AlClxF3−xvia its mechanochemical reaction with AlCl3

Abstract

Fluoroform (CHF₃) is a byproduct of CHF₂Cl with high global warming potential and long atmospheric lifetime, and its efficient utilization is a great challenge. The mechanochemical reaction between CHF₃ and AlCl₃ was studied for the first time, and the resultant ACFs (AlCl_xF_3−x, x ≈ 0.1) were characterized by ion chromatography, X-ray photoelectron spectroscopy and X-ray diffraction. The reaction mechanism is revealed via experiments and DFT calculation. Here, the reactivity of AlCl₃ is slightly higher than that of AlCl₂F and AlClF₂, while the reactivity of CHF₂Cl and CHFCl₂ is 2 to 6 orders of magnitude higher than that of CHF₃. The reaction is self-accelerated until CHF₃ is fully converted to CHCl₃ and ACFs with controllable F-content. The present work provides a viable approach to convert CHF₃ to CHCl₃ and ACFs at ambient temperature and pressure, which is superior to the mainstream incineration technique with great energy demand and environmental pollution, and sacrifice of the precious F-resource.