Combustion chemistry of Ti(OC3H7)4 in premixed flat burner-stabilized H2/O2/Ar flame at 1atm.

Abstract: The flame structure of the premixed H₂/O₂/Ar mixture (13%/14.5%/72.5%vol.) with and without 0.12vol.% of titanium tetraisopropoxide (Ti(OC₃H₇)₄) has been studied experimentally using the flame-sampling molecular beam mass-spectrometry and the microthermocouple techniques. The flame was stabilized on a flat burner at 1atm. The temperature and concentration profiles for Н₂, О₂, H₂O, and Ti(OC₃H₇)₄ have been measured. The mass peak intensity profiles of the titanium-containing species TiO₂, HTiO₂, TiO, HTiO, Ti, TiH, Ti₂O₃, TiO₃ have been measured as well. The experimental results were analyzed using kinetic modeling and quantum chemical calculations. It was established that hydrolysis of Ti(OC₃H₇)₄ is the dominating primary reaction of its decomposition in the flame. The rate constant of hydrolysis was estimated to be k =2×10¹² exp(−6160/T)mol⁻¹ cm³ s⁻¹. The results of quantum chemical computations support this conclusion. On the basis of concentration profiles of the Ti-containing intermediates, the schematic mechanism of the Ti(OC₃H₇)₄ conversion in the flame has been proposed. [Copyright &y& Elsevier]