Synthesis of Fe-SBA-15, and Ti-SBA-15 via sol-gel process of silatrane and activity study of Ti-SBA-15

Abstract

So-called SBA-15 (well-ordered hexagonal mesoporous silica) is an excellent support for any catalysts because of its high surface area, large pore size, and thick wall. Many metals, for examples, Fe, Ti and Mo, show a great catalytic performance in many reactions, especially, the oxidation reaction. Therefore, incorporating metals into the framework of SBA-15 is the aim of this work, including its activity study. The synthesis of M-SBA-15 (M = Fe, Mo, and Ti) is successfully achieved via a simple and energy-saving sol-gel process called a novel room temperature synthesis route, using a moisture-stable silatrane and a commercially available triblock copolymer PEO₂₀ -PPO₇₀ -PEO₂₀ as a silica precursor and a structure-directing agent, respectively. Ferric chloride, molybdenum glycolate, and titanium glycolate were used as metal sources. The reaction took place in an acidic media and, particularly, at room temperature. The SAXS patterns of all samples showed the characteristic peaks of a 2-D hexagonal mesoporous structure with p6mm space group. TEM images confirmed the formation of the regular hexagonal mesopore array. The BET analysis result showed high surface area and large pore size. DRUV results indicated that most of the metal ions were incorporated into the SBA-15 framework. The catalytic activity of the Ti-SBA-15 catalysts was investigated via oxidation reaction of styrene and it showed higher activity than pure SBA-15.