Degradation of Polyvinyl Chloride Microplastics via Hydrothermal Catalysis Using CoMn ₂ O ₄ Nanofibers

Microplastic pollution has emerged as one of the most critical environmental and societal concerns of the 21st century. Therefore, there is an urgent need to develop more cost-effective methods for degrading microplastics. Herein, we propose a facile, cost-effective, and mild hydrothermal strategy to degrade PVC microplastics without an external H 2 /O 2 supply. Reaction pathways for PVC microplastics upcycling were proposed based on product analysis. Mechanistic studies showed that the high catalytic activity of CoMn 2 O 4 spinel stems from the synergy between its Lewis and Brønsted acid sites, leading to dechlorination and carbenium ion generation. During the reaction, oxygen migration creates vacancies, which collaboratively catalyze the cleavage of C–C and C═C bonds with CoMn 2 O 4, forming low-carbon-chain organic compounds. This study introduces a simple, viable strategy for the upgrading of PVC MPs via hydrothermal catalytic reaction, offering significant potential for PVC MPs waste treatment and disposal.