Synthesis, Characterization and Catalysis of Delaminated Aluminosilicate Zeolites Derived From MWW-Type Borosilicate Zeolite Precursors

Layered MWW-type borosilicate zeolite precursors can be exfoliated via swelling in a fluoride/chloride surfactant mixture. The resulting exfoliated materials have significantly higher acid site density on the external surface than their 3D zeolite analogues. This acid-site density was measured by a new analytical method that employs bulky base molecules in solution, such as acridine in hexane. The advantage of the new method is its sensitivity which is limited by UV/Vis detection capability. The results of the new method correlate well with data from X-ray diffraction (XRD), nitrogen physisorption, nuclear magnetic resonance (NMR), infrared spectroscopy (IR), and transmission electron microscopy (TEM). The synthesis of the delaminated aluminosilicate zeolites is described, and their catalytic materials are discussed based on using the acylation of 2-methoxynapthalene by acetic anhydride as a model probe reaction.