Microwave-Powered Liquid Metal Degradation of Polyolefins

Abstract

Upcycling waste plastics is highly promising to tackle global white pollution while achieving sustainable development. However, prevailing approaches often encounter challenges in scalable engineering practices due to either insufficient plastic upcycling capability or arduousness in the separation, recovery, and purification of catalysts, which inevitably augments the cost of plastic upcycling. Here, the microwave-powered liquid metal synergetic depolymerization is presented to facilitate low-cost plastic upcycling. By leveraging the fluidity of liquid metals and their exceptional chemical-bond activation ability under microwave field, this method efficiently converts various polyolefins into narrowband hydrocarbon oil (Oil yield: 81 wt.% for polypropylene (PP), 85.9 wt.% for polyethylene (PE)) and high-value olefin monomers (C_2-4^ selectivity: 50% for PE, 65.3% for PP) over 30 successive cycles, resulting in a high turnover frequency of 2.83 kg_Plastic mL_{Liquid metal}⁻¹. These captivating advantages offered by electromagnetically-powered liquid metals are also supported by their self-separation features, thereby paving the way for large-scale engineering solutions in waste plastic upcycling.