Transformation of Vietnamese Kaolin into Zeolite Y – Templated Mesoporous Aluminosilicate for Efficient Catalysis in Polyolefin – Hydrocarbon Co-Pyrolysis

This study presents the first successful transformation of Vietnamese kaolin into a hierarchical mesostructured aluminosilicate catalyst, MAS(Y), via a sustainable two - step synthesis. Unlike conventional methods relying on high - purity chemicals, this appro ach employs thermally activated local kaolin and glass water to generate reactive aluminosilicate species, eliminating the need for petrochemical - derived precursors. The MAS(Y) material integrates ordered mesopores templated by CTABr with embedded zeolite Y domains, as confirmed by SAXS, TEM, and XRD analyses. It ex hibits a high specific surface area (971 m²/g), narrow pore size distribution (~3.2 nm), and thermal stability exceeding 900 °C. The NH₃ - TPD profile demonstrates the coexistence of weak (207.8 °C) and strong acid sites (447.0 °C, 510.4 °C), attributed to s urface silanol groups and framework Al³⁺ within zeolitic motifs. When applied in the catalytic co - pyrolysis of waste polypropylene (PP) with vacuum gas oil (VGO), MAS(Y) achieved liquid product yields exceeding 80%. Notably, the C₅ – C₁₂ and C₁₃ – C₁₈ hydrocar bon fractions peaked at PP/VGO ratios of 3:7 and 5:5, respectively. This work establishes a cost - effective and environmentally compatible pathway for upcycling abundant Vietnamese kaolin into high - performance acid catalysts, offering strong prospects for p lastic waste valorization and advanced refinery applications.