Preprint 74 Published
Preprint 74, "First-principles thermochemistry for the combustion of a TiCl4 and AlCl3 mix. ", has been published on the CoMo Group website.
AlCl3 is added in small quantities along with TiCl4 to industrial reactors during
the combustion synthesis of titanium dioxide nanoparticles in order to promote the
rutile crystal phase. Despite the importance of this process a detailed mechanism
including AlCl3 is still not available. This work presents the thermochemistry of
many of the intermediates in the early stages of the mechanism, computed using
quantum chemistry. The enthalpies of formation and thermochemical data for AlCl,
AlO, AlOCl, AlOCl2, AlOCl5Ti, AlO2, AlO2Cl, AlO2Cl2, AlO2Cl3Ti, AlO3Cl2Ti,
Al2Cl6, Al2O2Cl, Al2O2Cl3, Al2O3, and Al2O3Cl2 were calculated using density
functional theory (DFT). A full comparison between a number of ab initio methods
is made for one of the important species, AlOCl, in order to validate the use of DFT
and gauge the magnitude of errors involved with this method. Finally, equilibrium
calculations are performed to try to identify which intermediates are
likely to be
most prevalent in the high temperature
industrial process, and as a first attempt to
characterize the nucleation process.