Abstract
Ti(OPr’), vapor was pyrolyzed in dry nitrogen atmosphere using a simple tubular flow
reactor at 400 and 800°C. Well-defined spheroidal anatase TiO, particles showing mesoporous
surfaces of 30 m2 g-r and assuming two different morphologies (fused and
composite) were produced at the low temperature (ca. 4OO”Q whereas deformed spheroidal
particles of rutile-structured TiO, and surfaces of 12 mZ g ~’ were obtained at the high
temperature (ca. SOO’C). Particles of the high-temperature product were distinguished by a
low porosity and a uniform morphology (composite). The heat-induced modifications at
800°C may be ascribed to enhancements in (a) hydrolysis of Ti(OPr’),, by a possible
generation of water vapor as a secondary pyrolysis product of the alkoxide. (b) particle
growth via coalescence rather than by vapor deposition, and (c) particle sintering. The
pyrolysis products were characterized by X-ray diffrdctometry, high-resolution transmission
electron microscopy, and volumetry of nitrogen adsorption at liquid nitrogen temperature.