Synthesis of ∗BEA-type molecular sieves using mesoporous materials as reagents

Abstract A new method for synthesizing ∗BEA-type molecular sieves that involves the use of mesoporous materials as reagents is presented. Si-Beta (pure-silica, ∗BEA-type molecular sieve) is synthesized by heating TEAOH-impregnated Si-MCM-41 to 150°C for several days. The Si-Beta obtained has a small number of Q3 sites that are mostly siloxy groups that balance the charge of TEA cations. TEA cations can easily be removed by contacting the Si-Beta with acetic acid solution, and as a result, a highly hydrophobic Si-Beta is formed. Ti-Beta is synthesized from Ti-containing mesoporous silica or Ti-impregnated Si-MCM-41 without adding Al3+, alkali-metal cations and seeds. The incorporation of Ti into the ∗BEA structure is confirmed by UV–vis data. ∗BEA-type materials that contain other species such as Al, B, V, Zr and Zn can also be prepared.