Synthesis of new MCM-36 derivatives pillared with alumina or magnesia-alumina

Alumina and magnesia-alumina have been applied for pillaring the layered precursor of zeolite MCM-22. Calcination of such materials has led to new varieties of MCM-36 molecular sieves. Pillaring with alumina yields mesoporous materials with lower surface areas than those pillared with silica. The pillaring process with alumina strongly depends upon the preparation conditions of the alumina species and requires an elongated aging of the pillaring solutions. Application of magnesia in addition to alumina results in a higher exfoliation of the MCM-22 layers and incorporation of an increased amount of alumina into the materials. MgO × Al₂O₃ as pillaring agent yields a significantly higher mesoporosity in the range of 2-4 nm as compared with Al₂O₃. This synthesis method is a promising tool for tailoring the physicochemical properties and the structure of the slit-mesopores in relation to materials typically pillared with silica.