Characterization of Antimony catalysts inherited from plastic waste during chemical recycling

Plastic waste pollution has become a major environmental issue in modern society, increasing the demand for recycling polyethylene terephthalate (PET). Glycolysis process seems the better compromise to recycle PET in an economical and environmental way.In the frame of a PhD project, we study the activity of inherited species, and more specifically Antimony since it is by far the most used polycondensation catalyst for PET.Indeed, Sb is added as an oxide during polycondensation and converted into an organic species that act as a homogeneous catalyst. Therefore, Sb is present in every PET waste streams, and will affect PET chemical recycling.Studies have found that both oxidation states III and V can be found in waste streams, but the link with both species’ activities has not been thoroughly covered. We aim at establishing a clear link between oxidation state of antimony and the catalytically active forms in a glycolysis reaction.EXAFS and XANES are the most fitting analyses for that.