Gas phase dehydration of glycerol catalyzed by rutile TiO 2-supported heteropolyacids

Abstract

Gas phase dehydration of glycerol catalyzed by the rutile TiO 2-supported heteropolyacids was investigated. The TiO 2-supported heteropolyacid catalysts were prepared by the incipient wetness impregnation method using silicotungstic, phosphotungstic, and phosphomolybdic acids as active compounds. The as-prepared catalysts were characterized by X-ray diffraction, infrared spectroscopy, temperature programmed desorption of ammonia, and surface area measurement. The heteropolyacids supported by rutile TiO 2 were crystallites. The catalytic activity of the catalysts in the gas phase dehydration of glycerol was significantly affected by the type and loading of heteropolyacids. TiO 2-supported silicotungstic acid (20 wt.%) catalyst showed the highest catalytic activity with an acrolein selectivity of 80 mol% at a conversion of glycerol of 99% and a reaction temperature of 280 °C under ambient pressure. The possible reaction route in the gas phase dehydration of glycerol catalyzed by the TiO 2-supported heteropolyacid catalysts was also discussed briefly.