Oxygen Vacancy-Governed Opposite Catalytic Performance for C3H6 and C3H8 Combustion: The Effect of the Pt Electronic Structure and Chemisorbed Oxygen Species

Revealing the role of engineered surface oxygen vacancies in the catalytic degradation of volatile organic compounds (VOCs) is of importance for the development of highly efficient catalysts. However, because of various structures of VOC molecules, the role of surface oxygen vacancies in different catalytic reactions remains ambiguous. Herein, a defective Pt/TiO_2-x catalyst is proposed to uncover the different catalytic mechanisms of C₃H₆ and C₃H₈ combustion via experiments and theoretical calculations. The electron transfer, originated from the oxygen vacancy, facilitates the formation of reduced Pt⁰ species and simultaneously interfacial chemisorbed O₂, thus promoting the C₃H₆ combustion via efficient C═C cleavage. The reduced Pt nanoparticles facilitate the robust chemisorption of bridging dimer O₂^2- (Pt-O-O-Ti) species. This chemisorbed oxygen inhibits the C₃H₈ combustion by depressing C₃H₈ adsorption. This work offers insights for the rational design of highly efficient catalysts for activating the C═C bond in alkene or C-H bond in alkane.