Acid-degradable polymer-driven sustainable assembly of catalytically efficient single-crystalline hierarchical ZSM-5 zeolites

Despite single-crystalline hierarchical zeolites exhibit catalytic promise, their synthesis still necessitates energy-intensive and environmentally detrimental high-temperature calcination to remove organic templates. Herein, we introduce a sustainable approach for synthesizing large-sized single-crystalline hierarchical ZSM-5 using an acid-degradable polymer (ADP) as a versatile template. The ADP not only facilitates the formation of ZSM-5 with a broad range of n(SiO 2 )/n(Al 2 O 3 ) ratios and tunable mesoporosity but also undergoes complete removal from the zeolite during the Na-to-H acid exchange without calcination. Mechanistic investigations reveal that ADP induces the formation of ZSM-5 framework by interacting with hydroxyl groups and Q 2 /Q 4 Si species while simultaneously guiding the ordered assembly of nanocrystals to achieve a single-crystalline and hierarchical structure. Notably, ADP, acting as a hard template, remains embedded within the hierarchical pores during crystallization. Life cycle assessment (LCA) demonstrates that this strategy significantly reduces environmental impacts when compared to traditional synthesis methods. The resulting zeolite shows superior thermal stability and enhanced mass transport properties due to its unique single-crystalline and hierarchical structure, translating to exceptional catalytic performance in low-density polyethylene pyrolysis and methanol-to-propylene reactions. This work offers an eco-friendly paradigm for zeolite fabrication by leveraging ADP’s availability, low cost, and acid degradability, and aligns with green chemistry principles.