Complex Solid Superacid Catalyst WO_3-ZrO_2-SO_4^(2-) Structure of Acid Sites on the Catalyst

摘要

A new type of complex solid superacid catalyst WO3-ZrO2-SO42-with an acid strength H0≤-16.04 wasprepared by kneading Zr（OH）4 or amorphous ZrO2 with tungstic acid（H2WO4）（W/Zr=0.15）,followed byexposing this complex hydroxides to 0.5 tool/L H2SO4,calcining in air at 700～800℃ for 3h.This catalystpossesses both strong Bronsted acidity and strong Lewis acidity experimentally showed by IR observation ofpyridine absorbed on it.XPS and AES techniques were employed to examine the valence states of tungsten,zirconium,sulfur and their interactions.The structure of sulfur species was studied by infrared spectroscopyand a structure model of active site was proposed upon these results.