Ru Single-Atom Anchored Zeolite for Selective Upcycling of Polyolefins Into Butanes.

Abstract

Precisely upcycling polyolefins into specific compounds remains a formidable challenge in sustainable chemistry. Here, we report a spatially confined relay catalysis strategy enabled by Ru single-atom-anchored MOR zeolite (Ru1@MOR), which achieves a maximum C4 alkane selectivity of 63.4% and a production rate of 4516.4 mmol gRu -1 h-1 in the hydrocracking of low-density polyethylene, outperforming reported catalysts to date. Combined AC HAADF-STEM, solid‑state NMR, and density functional theory calculations demonstrated that isolated Ru1 sites are coordinatively situated on the inner surface of MOR, forming Ru─O─Si and Ru─O─Al linkages, which enhance the electrophilicity of framework Al sites and the Brønsted acidity strength of adjacent bridging hydroxyl groups, thereby endowing the catalyst with improved hydride abstraction capability while retaining the intrinsic carbenium-ion‑mediated cracking pathway. Life‑cycle assessment further substantiates the minimal operating cost and environmental impacts of this system, and a techno‑economic projection for a 10 000-tonne-per-year butane facility can yield annual alkane revenues exceeding US$1.5 million. This work provides a retrosynthesis-inspired, atom-economical paradigm for plastic waste valued, highlighting the role of precisely engineered single‑atom/zeolite interfaces in selectivity toward targeted hydrocarbon fractions.