Tackling chlorine poisoning for robust upcycling of PVC-contaminated plastic streams

Abstract

Catalytic upcycling of polyolefin waste into valuable chemicals presents a promising solution to tackle the growing environmental crisis caused by plastic pollution while promoting a circular economy. However, processing plastic wastes that contain polyvinyl chloride (PVC) poses significant hurdles, as chlorine released during PVC breakdown can poison and deactivate metal catalysts. Here we introduce a non-thermal surface reconstruction strategy that can restore the activity of chlorine-poisoned catalysts at room temperature. Leveraging the potent reductive reactivity of NaBH4, chlorine contaminants on the catalyst surface are effectively eliminated, restoring the active sites. The clean-surface Ru catalysts exhibit enhanced chlorine tolerance and recyclability in the hydrogenolysis of PVC-polyolefin mixtures, offering a practical catalytic pathway for valorizing chlorine-containing plastic waste. Notably, these catalysts also display great activity in polyolefin hydrogenolysis, reaching a space-time yield of solids to condensable products of 5982 gPE · gRu−1 · h−1. This study opens new avenues for plastic upcycling and contributes to sustainable waste management, bringing us closer to a circular economy. Chlorine released from mixed plastic waste can deactivate catalysts and hinder recycling. Here, the authors report a room-temperature treatment to clean ruthenium surfaces, restoring highly active and reusable catalysts for plastic upcycling.