Graphical abstract Crystalline TiO 2 particles were produced in a tubular flow reactor by vapor synthesis using titanium tetrachloride as a starting material in oxygen containing atmospheres. The general reaction is: TiCI 4 + O 2 → TiO 2 + 2Cl 2. The dependence of particle size, morphology and crystalline phase of titania on temperature schedules including the reactor temperature, the oxygen preheated temperature and the product cooling measure was explored. It is found that there are two opposite effects of temperature on particle size and cystalline phase content. The particle size distribution, SEM and TEM of the resulting powders show that the grain size is controlled by the relative magnitudes of the nucleation rate and growth rate, both of them being subject to temperature schedules. XRD indicates that particles crystalline phase is predominately anatase and the rutile content increment is not consistent with temperature increase. Anatase titania can be converted to rutile by the addition of crystal modifier AICI 3. The element analysis by EDS shows that AI enriches on the particle outer surface. Fig. 5. Schematic of gas-to-particle conversion process.