Structural Characteristics and Catalytic Performance of Nanosheet-Like Small-Crystal Y Zeolite

This paper presents a comparative study on the structural and thermal stability differences between a nanosheet-like small-crystal Y zeolite (NaY-Ur) and a conventional small-crystal Y zeolite (NaY-Con), and further investigates the acidity and catalytic cracking performance of the corresponding ultrastable Y zeolite (USY) samples obtained after hydrothermal ultrastabilization. Compared with the conventional NaY (~350 nm), NaY-Ur exhibits a reduced crystal size of ~221 nm and an average nanosheet thickness of ~83 nm.

After calcination at 850 °C, NaY-Ur retains a significantly higher XRD relative crystallinity (31%) and BET surface area retention (11.0%) than those of NaY-Con (23% and 4.7%, respectively), demonstrating a synergistic thermal stability advantage in both crystal structure and pore structure. XRD, XRF, EDS, and OH-IR analyses reveal that NaY-Ur possesses a higher framework SiO2/Al2O3 ratio and a surface Si-enrichment feature, providing the structural basis for its superior thermal stability over NaY-Con.