Synthesis and characterization of tungsten-substituted SBA-15: An enhanced catalyst for 1-butene metathesis

Abstract

Tungsten-substituted mesoporous SBA-15 materials have been successfully synthesized in a one-step co-condensation sol–gel method. The resultant materials have been characterized by X-ray diffraction (XRD), nitrogen adsorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), 29Si MAS NMR, UV–Visible spectroscopy and Raman spectroscopy. Results of these analyses indicate that the tungsten oxide species are highly dispersed in the silica-based framework structure. The tungsten-substituted mesoporous SBA-15 catalysts show excellent catalytic performance in the metathesis of 1-butene to high value olefins. The conversion of 1-butene is as high as 92.6% with metathesis selectivity reaching 68.3% which is more than double that of amorphous silica supported tungsten oxide catalyst (25.4%) prepared by the conventional impregnation method. The high dispersibility of tungsten oxide species, strong interaction between tungsten oxide species and silica as well as the pore structure of the tungsten-substituted mesoporous SBA-15 are critical factors leading to the excellent catalytic behavior.