Crystal size effects of nanocrystalline-titania catalyst synthesized by glycothermal method on gas phase photo-oxidation of 2-propanol

Abstract

The nanocrystalline-titanium (IV) oxide catalysts were synthesized by glycothermal of titanium tetra-tert butoxide, TTB, in mixture of 1,4 butanediol and 2-propanol at high temperature (300℃) for 2 hrs. Catalyst characterization by X-ray diffraction technique confirmed that all as-prepared titanium (IV) oxide catalysts contained only anatase phase. The crystal size of anatase-titanium (IV) oxide prepared by this method depended on volume ratio between 1,4 butanediol and 2- propanol. It was shown that the smallest and highest crystal size occurred when the volume ratio between 1,4 butanediol and 2-propanol of 2:3 and 0:5, respectively. The optimal crystal size for photo-oxidation reaction of 2-propanol was about 23 nm giving highest 2-propanol conversion to carbon dioxide and water. The smaller and larger crystal sizes showed lower photoactivity due to the effect of electron-hole recombination process and 2-propanol adsorbability on the surface of catalyst.