Highly efficient and stable plastic upcycling via metal encapsulation in zeolites

Catalytic upcycling of waste plastics alleviates their environmental and health hazards while providing renewable carbon feedstocks for sustainable energy and chemical production1-6. Bifunctional metal-zeolite catalysts hold great promise for this process, yet suffer from insufficient efficiency, limited durability, and excessive metal usage. Here we show that encapsulating metal nanoparticles within zeolites unlocks the full potential of bifunctional catalysis for plastic hydrocracking. The H-Beta zeolite-encapsulated ruthenium catalyst (Ru@H-Beta) efficiently converts, at only 0.14 wt% Ru loading, polyethylene to gasoline-range hydrocarbons with ~90% yield in 0.5 h at 275 ºC, achieving an unprecedented liquid fuel formation rate of 61 g gcat-1 h-1 (43,700 g gmetal-1 h-1)—6‒10 times higher than conventional supported catalysts. Notably, the single-run Ru usage for Ru@H-Beta is merely 42 gRu tonLDPE-1—the minimum among the reported metal-based catalysts, underscoring its exceptionally low resource footprint. Furthermore, unlike supported catalysts that deactivate rapidly, encapsulating Ru nanoparticles in Ru@H-Beta maintain ultra-stable performance over 100 recycling runs and exhibit high activity for diverse plastics—including high-density polyethylene, polypropylene, and polystyrene (converted to gasoline fuels), as well as polyethylene terephthalate (converted to terephthalic acid), even from post-consumer wastes. Notably, encapsulation opens an unconventional bifunctional mechanistic pathway, where metal sites are used to activate H2 but not directly exposed to the polymer, thus preventing catalyst poisoning and improving hydrocarbon selectivity; the metal-activated hydrogen species migrate to the zeolite external surface and accelerate hydrocracking without favoring short chain scission. This work unlocks a straightforward and general design strategy for high-efficiency, robust metal-zeolite catalysts and prompts a fundamental rethinking of bifunctional catalysis