Local Environment and Electronic Structure of Pt-TiO<sub>2</sub> Catalysts Define the Reactivity of CO Oxidation and C<sub>3</sub>H<sub>8</sub> Combustion: the Crystal Phase of TiO<sub>2</sub> Determining
Jinshi Dong, Ting Li, Shengtong Li, Panpan Chang, Qianqian Jin, Jiaqiang Yang, Zhuangzhuang Lai
Abstract
CO and C 3 H 8, 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 TiO 2 (anatase and rutile) as supports were fabricated and investigated for CO oxidation and C 3 H 8 combustion. The surface nature of TiO 2 dramatically affects the local environment and electronic properties of supported Pt. Pt-TiO 2 (R) exhibited superior activity for CO oxidation, whereas Pt-TiO 2 (A) showed higher reactivity for C 3 H 8 total oxidation. It is concluded that Pt-TiO 2 (R) contains more oxygen vacancies at the interfacial Pt perimeter sites than Pt-TiO 2 (A) after reduction pretreatments, which facilitates CO oxidation through the Mars–van Krevelen (MvK) mechanism. The electron-deficient Pt in Pt-TiO 2 (A) promotes the adsorption and activation of C 3 H 8, and the amount of charge transfer between Pt and adsorbate intermediates during C 3 H 8 oxidation determines the preference of C-C cleavage or dehydrogenation. Lower charge transfer in Pt-TiO 2 (A) makes C–C cleavage more efficient and contributes to the total oxidation of C 3 H 8 . This work emphasizes the importance of engineering material’s local environment and electronic structure to design high-performance oxidation catalysts.