Synthesis and catalytic properties of highly ordered mesostructured silica-pillared a-zirconium phosphate: Self-assembly via interlayered templating method

摘要

We present a facile organic surfactant templating self-assembly method with suitable cationic surfactant method for silica-pillared α-ZrP with ordered interlayered mesoporous structure. The synthetic silica-pillared α-ZrP powders with interlayer spaces and interlayer pore sizes ranging from 3.0 to 3.7 nm and 1.4 to 2.1 nm by varying the molar ratio of surfactant/α-ZrP during self-assembly process. The structure and properties of the silica-pillared α-ZrP powders were characterized by using XRD, SEM/TEM, FT-IR, TPD and N_2 adsorption-desorption isotherms systematically. A bilayers arrangement-molecular micelles_1 phase transformation formation mechanism was proposed for the molecular assembly. The acylation reaction of fatty acid methyl esters (methyl stearate) with ethanolamine to form monoethanolamides was chosen as a probe reaction to evaluate the catalytic activity of the resulting microspherical silica-pillared α-ZrP materials, which showed high activity, with about 92.9% methyl stearate conversion at 393 K for 16 h. The enhanced performance in the reaction is determined by the large surface area, ordered pore size and the increased number of acidic sites in the silica-pillared α-ZrP powders.