Efficient H2 Production from PET Plastic Wastes over Mesoporous Carbon-Supported Ru-ZnO Catalysts in a Mild Pure-Water System

The massive consumption of plastic is posing severe pollution-related challenges globally. As the most abundant polyester plastic, polyethylene terephthalate (PET) waste represents a largely untapped resource for generating chemicals and fuels. However, the current widespread use of alkali/organic solvents and the complex processing of PET reduce its environmental sustainability. Herein, a novel and simple one-pot strategy was first reported for the catalytic conversion of PET into H2 fuel and terephthalic acid in a pure-water system under mild conditions. A high H2 yield of 19.97 mol/kgPET and carbon conversion efficiency of 97.22% were obtained for the Ru-5ZnO/ mesoporous carbon (MEC) catalyst at a low temperature of 250 degrees C. This process proceeds through tandem catalytic reactions with an initial PET depolymerization step, followed by in situ aqueous phase reforming (APR) of ethylene glycol of Ru. Remarkably, ZnO inhibited the deactivation of Ru/MEC in the PET depolymerization stage, causing an increase in H2 production from the in situ APR stage. Importantly, this strategy was successfully applied to four types of real-world PET waste and their mixtures, demonstrating that it has considerable potential in practical applications and provides a sustainable and clean solution to the plastic waste problem.