Synthesis of Organic Pillared MFI Zeolite as Bifunctional Acid–Base Catalyst

Organic pillared MFI zeolite has been synthesized by detemplation of diquaternary ammonium surfactant ([C22H45–N+(CH3)2–C6H12–N+(CH3)2–C6H13]­Br2, C22‑6‑6) and intercalation of arylic silsesquioxane (1,4-bis­(triethoxysilyl)­benzene, BTEB) molecules between multilamellar MFI layers. The acid extraction and UV light radiation were sequentially employed for removal of C22‑6‑6 surfactant located not only between MFI layers but also in the zeolite micropores. The removal of the C22‑6‑6 template using a nonthermal calcination method prevents the condensation of external silanol groups of zeolitic layers stacked next to each other, which allows intercalation of BTEB molecules between the zeolitic layers and their successive reaction with the silanol groups to form the organic pillared zeolite structure. A post-treatment amination of the resultant zeolite sample introduced amino groups in the organic BTEB pillars. The acid sites from the zeolite framework aluminum and basic sites from the amino groups in BTEB pillars endow organic pillared MFI bifunctionality for cascade catalytic reactions. The synthesis of organic pillared MFI is a new addition to the structural modifications of lamellar zeolite with more open structures for processing bulky molecules. The resultant inorganic–organic hybrid zeolite structure creates new opportunities for potential applications of lamellar zeolites with tailored physicochemical properties.