Malin Eqi, Yi Yang, Jiashuo Zheng, Guangjun Wu, Yuchao Chai, Landong Li
ABSTRACT Converting polyethylene to liquid fuels requires Brønsted acidity, yet conventional acidic zeolites suffer from rapid coking and excessive gas formation. Despite Na‐exchanged zeolites are well‐known to resist coking in many cracking reactions, they are generally considered catalytically inert for polyethylene cracking due to absent acidity. Here, we show that encapsulated palladium nanoparticles in Na‐ZSM‐5 catalyze efficient polyethylene hydroconversion to C 5 ‐C 9 alkanes with minimal gas yield and negligible coke formation. Mechanistic studies reveal that dihydrogen undergoes heterolytic dissociation at the confined Pd‐zeolite interface, concurrently generating PdH hydrides and bridging hydroxyl groups that function as Brønsted acid sites. These dynamically created acid centers drive selective C─C bond scission via classical β‐scission pathways while circumventing the deleterious side reactions. This study establishes a general paradigm for adaptive catalysis wherein active sites are created in situ within otherwise non‐acidic frameworks, offering new strategies for selective bond activation.