Electron-Enriched Pt-In Synergistic Sites for Highly Selective and Direct Photo-Reforming of PET Plastic Wastes into...

Photocatalytic selective upcycling of polyethylene terephthalate (PET) waste into valuable C₂ products is an ideal strategy. However, over-oxidation and nonselective activation of C─C/C─O bonds by active sites in the local microenvironment have limited prior studies to produce C₂ products. By designing Pt/ZnO-ZIS catalysts that feature a dynamically coupled Pt-In dual-site synergistic interface, this study achieves in situ upcycling of PET wastes via tuning the electronic structure and chemical environment of the Pt-In active sites and optimizing the adsorption configuration of plastic wastes. The dual active sites (Pt-In), which are spatially adjacent yet functionally distinct, achieves an HOAc production rate of 882.46 µmol g^-1 h^-1 with nearly 100% selectivity. Detailed characterizations and DFT calculations reveal that the high selectivity is attributed to the Pt sites adsorbing and protecting the terminal hydroxyl group (-OH) oxidation, and then activating the C─O bond to undergo proton substitution. The electron-rich Pt sites further inhibit the over-oxidation of C─C bond, ensuring high selectivity of HOAc. Simultaneously, the In sites facilitate oxidation of -OH to form carboxyl species during the reaction. This study provides an insightful understanding of dual sites with dynamic reconstruction toward highly selective photo-reforming of plastic wastes at the atomic scale.