Regulating Cu ⁺ and Cu ⁰ Sites for the Upcycling of Waste PET Plastic to PX

P-xylene (PX) is an essential high-value chemical with a wide range of applications. The use of waste plastics to produce high-valuable chemicals is considered to be one of the most effective and sustainable waste plastic recycling routes. Herein, a simple and efficient CuAlOX catalyst was developed for the upcycling of waste PET plastic to PX. The yield of PX was up to 98%, and the catalyst can be reused for five runs without obvious deactivation. Mechanism investigation indicated that Cu+ and Cu0 are the possible active sites, and the best ratio of Cu+ to Cu0 is 2.9. The optimal Cu+ and Cu0 sites are favorable for the absorption of ester, carboxylic acid, and alcohol groups and the desorption of PX, which is key for the selective hydrodeoxygenation of PET to PX.