Intramolecularly Synergic Catalysis Enables Efficient Closed-Loop Recycling of Polyesters and Polycarbonates

Efficient and selective chemical recycling of commercial plastics back to monomers is a pivotal strategy for achieving a circular plastics economy. However, rare catalysts can deliver versatility in both polymerization and depolymerization processes. Herein, we report an efficient and tolerant dinuclear zinc catalyst for the bulk depolymerization of various polyesters and polycarbonates to the corresponding cyclic monomers with >99% selectivity, and for repolymerization to virgin materials, through an intramolecular bimetallic synergistic dual-activation mechanism. A record-breaking activity of up to 43 kg of polymer/g of catalyst per hour was observed in the catalytic bulk poly(_L-lactic acid) depolymerization with microwave assistance. The catalyst could be recycled several times without obvious loss in activity and selectivity. This work provides an effective guideline for catalyst design that closes the loop for commercial plastics, offering a direct route to transform plastic waste into renewable feedstocks and advancing a truly sustainable materials economy.