The influence of the molar ratio [H2O]/[Ti(OR)4] on the kinetics of the titanium-oxo-alkoxy clusters nucleation

The influence of the molar ratio h = [H 2 O]/[Ti(OR) 4 ] (R = Pr i ) on the kinetics of the titanium-oxo-alkoxy clusters (TOAC) nucleation was studied. Clusters were formed by the titanium tetraisopropoxide Ti(OPr i ) 4 chemical reaction with H 2 O in n -propanol solution, with the fixed concentration of Ti(OPr i ) 4 ( c = 0.04 M), molar ratio h ∈ {11, 14, 17, 20} and temperature T ∈ {298, 308, 318} K. It was determined that the isothermal rate of clusters nucleation is a power law function of the molar ratio h . The kinetic parameter β value changes complexly as h and T change. The value of apparent activation energy of the nucleation process ( E a ) decreases with the increase of value h . It was found that nucleation is a reaction with complex kinetics whose elementary stages are hydrolysis Ti(OR) 4 to Ti(OR) 3 OH and formation of titanium-oxo-alkoxy clusters [Ti n + β O β ](OR) 4 n + 2β through the alcoxolation reaction.