The kinetics of propylene oxidation to propylene oxide (PO) with H2/O2 mixtures on gold supported on the mesoporous titanium silicate, Ti-TUD, was investigated using Langmuir−Hinshelwood (L−H) models and power−rate law (PRL) models. The catalyst gave stable activity and was appropriate for the kinetic studies, giving high selectivity to PO (>95%) at low conversions of propylene (<6%). The best L−H fit, based on the F test and obtained using nonlinear regression, gave a rate expression of the form, rPO = k[(α(H2)1/2 (O2))/(1 + α(H2)1/2(O2))](H2)1/2[γ(C3H6)/(1 + γ(C3H6))], with an F value of 4.50. The PRL model, also analyzed using nonlinear regression, gave a rate expression, rPO = k(H2)0.60(O2)0.25(C3H6)0.36, which provided a better fit to the data, with an F value of 2.11. The best model was a hybrid of the form rPO = k(H2)l(O2)m(C3H6)/[kD/κ + (C3H6)], with an F value of 1.76. This hybrid model was also proven as the best model based on a model probability criterion. The mechanistic origin of these expressions, which include coupled and sequential cycles, is discussed. Temperature-programmed desorption measurements of propylene, hydrogen, and oxygen showed that these species were adsorbed on the catalyst at the reaction temperature (423 K). The quantities adsorbed were consonant with the equilibrium adsorption constants calculated from the fits of the L−H model with three independent adsorption sites, a Temkin−Frumkin model for a nonuniform surface, and the exponents in the PRL models.