Photothermal recycling of waste polyolefin plastics into liquid fuels with high selectivity under solvent-free conditions

The widespread use of polyolefin plastics in modern societies generates huge amounts of plastic waste. With a view toward sustainability, researchers are now seeking novel and low-cost strategies for recycling and valorizing polyolefin plastics. Herein, we report the successful development of a photothermal catalytic recycling system for transforming polyolefin plastics into liquid/waxy fuels under concentrated sunlight or xenon lamp irradiation. Photothermal heating of a Ru/TiO2 catalyst to 200-300 & DEG;C in the presence of polyolefin plastics results in intimate catalyst-plastic contact and controllable hydrogenolysis of C-C and C-H bonds in the polymer chains (mediated by Ru sites). By optimizing the reaction temperature and pressure, the complete conversion of waste polyolefins into valuable liquid fuels (86% gasoline- and diesel-range hydrocarbons, C-5-C-21) is possible in short periods (3 h). This work demonstrates a simple and efficient strategy for recycling waste polyolefin plastics using abundant solar energy. Sustainable recycling of waste plastics is of highly strategic significance. Here, the authors report a photothermal recycling system for transforming polyolefin plastics into high-selectivity liquid fuels through the synergistic utilization of ultraviolet, visible, and near-infrared irradiation.