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

Abstract The flame structure of the premixed H 2 /O 2 /Ar mixture (13%/14.5%/72.5% vol.) with and without 0.12 vol.% of titanium tetraisopropoxide (Ti(OC 3 H 7 ) 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 1 atm. The temperature and concentration profiles for Н 2 , О 2 , H 2 O, and Ti(OC 3 H 7 ) 4 have been measured. The mass peak intensity profiles of the titanium-containing species TiO 2 , HTiO 2 , TiO, HTiO, Ti, TiH, Ti 2 O 3 , TiO 3 have been measured as well. The experimental results were analyzed using kinetic modeling and quantum chemical calculations. It was established that hydrolysis of Ti(OC 3 H 7 ) 4 is the dominating primary reaction of its decomposition in the flame. The rate constant of hydrolysis was estimated to be k  = 2 × 10 12  exp(−6160/ T ) mol −1  cm 3  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(OC 3 H 7 ) 4 conversion in the flame has been proposed.