Oxygen Vacancy-Governed Opposite Catalytic Performance for C 3 H 6 and C 3 H 8 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 C 3 H 6 and C 3 H 8 combustion via experiments and theoretical calculations. The electron transfer, originated from the oxygen vacancy, facilitates the formation of reduced Pt 0 species and simultaneously interfacial chemisorbed O 2 , thus promoting the C 3 H 6 combustion via efficient C═C cleavage. The reduced Pt nanoparticles facilitate the robust chemisorption of bridging dimer O 2 2- (Pt-O-O-Ti) species. This chemisorbed oxygen inhibits the C 3 H 8 combustion by depressing C 3 H 8 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.