Current perspective on heterogeneous thermal catalytic approaches for closed-loop polyolefin plastic recycling

The escalating accumulation of polyolefin (PO) waste presents one of the most formidable challenges in sustainable catalysis. Heterogeneous catalytic upcycling has emerged as a promising route toward chemical circularity, yet genuine closed-loop recycling—where polymers are converted back into monomers for repolymerization—remains challenging. This perspective critically examines three catalytic pathways: ethylene metathesis, hydrocracking coupled with steam cracking, and high-temperature or tandem catalytic cracking. While each offers distinct advantages in selectivity, scalability, or process simplicity, none independently satisfy the combined criteria of low energy demand, carbon neutrality, and economic viability. Future progress requires low-carbon, renewable-powered catalytic pathways, realistic PO waste investigation, highly selective and adaptive catalysts, and integration of techno-economic and life-cycle assessments. By bridging molecular-level catalyst design with systems-level process engineering, heterogeneous catalysis can transform PO waste from a persistent pollutant into a renewable carbon resource, forming the cornerstone of a sustainable, circular plastic economy.