Mechanochemical destruction of perfluorinated pollutants and mechanosynthesis of lanthanum oxyfluoride: A Waste-to-Materials process

Perfluorinated chemicals (PFCs) are attracting increasing concern due to their chemical stability and toxicity, which make them classifiable as persistent organic pollutants. However, such compounds are employed for the manufacture of many industrial and consumer products, hence their substitution is not possible in the near future. Suitable technologies for PFCs environmentally sound management are necessary. High energy ball milling With KOH has been proved to obtain PFCs safe destruction, but With excessive reagent. In the present study, a Waste-to-Materials solution is proposed: PFCs are co-milled with stoichiometric amounts of La2O3 and thus are fully converted into LaOF, a noteworthy luminescent material with many potential industrial applications. Reaction mechanism is also investigated: Ball milling process activates La2O3; this latter provokes oxidation to CO2 and carbonization of PFCs; fluorides are incorporated into the La2O3's lattice to form the oxyfluoride. Interestingly, kinetic analysis suggests that the mechanical activation of La2O3 might follow a zeroth-order reaction rate. (C) 2017 Elsevier B.V. All rights reserved.