Kinetic modeling of the total oxidation of propane over anatase and vanadia sputter deposited catalysts

Using an innovative magnetron sputter deposition technique, a set of titania (anatase), vanadia and vanadia–titania (anatase) based catalysts on porous SiO2 and non-porous SiO2–ZrO2 supports is prepared. These catalysts are tested for propane total oxidation at atmospheric pressure, a constant oxygen inlet partial pressure of 28.4 kPa and temperatures from 733 to 773 K. The inlet ratio of oxygen and propane is varied between 7.7 and 85.3 mol mol−1. A longer TiOx sputter deposition time has a beneficial effect on the propane total oxidation turnover frequency (TOF). Furthermore, the use of a porous support results in higher TOF. Starting from eleven possible rate equations, the one corresponding to a Mars–van Krevelen (MVK) mechanism, involving one active site in the reduction and reoxidation step, is globally the most significant. A pronounced compensation effect is observed for the rate coefficients of the reoxidation and reduction steps.