O3 titration for synthesis of Pt-Pd core-shell structural catalyst and its catalytic performance on C-H bond activation

• Published in: Applied catalysis. A, General General, 2022-02, Vol.631, p.118487, Article 118487
• Main Authors: Geng, Haojie, Li, Zhuwan, Li, Dongwei, Zhang, Hao, Wu, Xinyu, Zhang, Li
• Format: Article
• Language: English
• Subjects: Alkanes; C-H bond activation; Catalysts; Chemical synthesis; Core-shell structure; Hydrogen bonds; Oxygen; Oxygen titration; Palladium; Palladium base alloys; Platinum; Pt-Pd bimetallic catalyst; Segregation; Shells; Titration
• ISSN: 0926-860X; 1873-3875
• DOI: 10.1016/j.apcata.2022.118487

A novelty catalyst synthesis method is introduced in this investigation, which employs O3 pulse to induce a segregation of Pd-Pt species to synthesize Pt-Pd core shell structural catalyst. In Pt-Pd alloy, O3 releases highly active oxygen (O*) species (O3→O2 + O·), which combine with Pd species or Pt species selectively. This combination induces a relative migration between Pd and Pt atoms, forming Pt-core@PdO-shell structural catalyst, which meets the thermodynamic stability of Pt-Pd alloy. Core shell structural catalyst displays a better catalytic performance for C-H bond activation. Experimental results indicate core-shell structural catalyst produces more highly active oxygen species than alloy catalyst does. These highly active oxygen species activate C-H bond in alkanes, contributing to a higher catalytic reactivity. In addition, the interaction between Pt-core and PdO-shell lowers the binding energy of ionic Pd species, which facilitates the release of reactive oxygen species. [Display omitted] •Highly active oxygen induces the element segregation of Pd and Pt species.•Oxygen selective combination promotes the relative migration between Pd and Pt species.•Core shell structural catalyst produces more highly active reaction intermediates.•Core shell structural catalyst displays a better catalytic performance for C-H bond activation.