Local Environment and Electronic Structure of Pt-TiO2 Catalysts Define the Reactivity of CO Oxidation and C3H8 Combustion: the Crystal Phase of TiO2 Determining

CO and C3H8, as typical inorganic and organic gaseous pollutants, respectively, require distinct oxidation catalysts for efficient conversion due to their unique properties. In this work, Pt catalysts with different crystal phases of TiO2 (anatase and rutile) as supports were fabricated and investigated for CO oxidation and C3H8 combustion. The surface nature of TiO2 dramatically affects the local environment and electronic properties of supported Pt. Pt-TiO2(R) exhibited superior activity for CO oxidation, whereas Pt-TiO2(A) showed higher reactivity for C3H8 total oxidation. It is concluded that Pt-TiO2(R) contains more oxygen vacancies at the interfacial Pt perimeter sites than Pt-TiO2(A) after reduction pretreatments, which facilitates CO oxidation through the Mars–van Krevelen (MvK) mechanism. The electron-deficient Pt in Pt-TiO2(A) promotes the adsorption and activation of C3H8, and the amount of charge transfer between Pt and adsorbate intermediates during C3H8 oxidation determines the preference of C-C cleavage or dehydrogenation. Lower charge transfer in Pt-TiO2(A) makes C–C cleavage more efficient and contributes to the total oxidation of C3H8. This work emphasizes the importance of engineering material's local environment and electronic structure to design high-performance oxidation catalysts.