Role of the In-Situ-Formed Surface (Pt–S–O)-Ti Active Structure in SO<sub>2</sub>-Promoted C<sub>3</sub>H<sub>8</sub> Combustion over a Pt/TiO<sub>2</sub> Catalyst
Wei Chen, Juan Zheng, Yarong Fang, Yutao Wang, Jinpeng Hu, Yuhua Zhu, Xiaoxiao Zhu, Weihao Li, Qian Zhang, Chuanqi Pan, Baojian Zhang, Xiaofeng Qiu, Sibo Wang, Shuang Cui, Jinlong Wang, Jinsong Wu, Zhu Luo, Yanbing Guo
Abstract
Typically, SO 2 unavoidably deactivates catalysts in most heterogeneous catalytic oxidations. However, for Pt-based catalysts, SO 2 exhibits an extraordinary boosting effect in propane catalytic oxidation, but the promotive mechanism remains contentious. In this study, an in situ-formed tactful (Pt–S–O)-Ti structure was concluded to be a key factor for Pt/TiO 2 catalysts with a substantial SO 2 tolerance ability. The experiments and theoretical calculations confirm that the high degree of hybridization and orbital coupling between Pt 5d and S 3p orbitals enable more charge transfer from Pt to S species, thus forming the (Pt–S–O)-Ti structure with the oxygen atom dissociated from the chemisorbed O 2 adsorbed on oxygen vacancies. The active oxygen atom in the (Pt–S–O)-Ti active structure is a robust site for C 3 H 8 adsorption, leading to a better C 3 H 8 combustion performance. This work can provide insights into the rational design of chemical bonds for high SO 2 tolerance catalysts, thereby improving economic and environmental benefits.