Synthesis, characterization and catalytic activity of ordered SBA-15 materials containing high loading of diamine functional groups

Diamine-functionalized mesoporous SBA-15 materials have been synthesized by co-condensation of tetraethylorthosilicate (TEOS) with [3-(2-aminoethyl aminopropyl)]trimethoxysilane (ATMS) using amphiphilic block copolymer P123 as pore-directing agent under the aid of inorganic salt NaCl and with prehydrolysis of TEOS prior to the addition of organosiloxane. The functionalized materials have hexagonal mesostructure ordering, narrow pore-size distribution with diameter around 60 Å, and high loadings of amino groups (up to 3.49 mmol g−1). Prehydrolysis of TEOS was a key step for preparation of well-ordered mesoporous materials with amino functionalities. Inorganic salt had great influence on the ordering of mesostructure and the morphology of the resultant materials. The diamine-functionalized materials showed better catalytic performance than the aminopropyl-functionalized counterpart in the Knoevenagel reaction of benzaldehyde with ethyl cynoacetate to form α,β-unsaturated compound in liquid phase.