Chinese Journal of Catalysis ›› 2020, Vol. 41 ›› Issue (4): 719-729.DOI: 10.1016/S1872-2067(19)63395-4

• Articles • Previous Articles    

Effect of pH on the catalytic performance of PtSn/B-ZrO2 in propane dehydrogenation

Zhonghai Jia,b, Dengyun Miaoa, Lijun Gaoa, Xiulian Pana, Xinhe Baoa   

  1. a State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China;
    b University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2019-09-30 Revised:2019-10-08 Online:2020-04-18 Published:2019-12-12

Abstract: Boron-modified ZrO2 (B-ZrO2) was synthesized under various pH values (9, 10, and 11) and used as the supports of PtSn catalysts (PtSn/B-ZrO2-x) for non-oxidative dehydrogenation of propane. The NH3-TPD and pyridine IR show that only Lewis acid is present and the acid strength increases with the synthesis pH. PtSn/B-ZrO2-10 exhibits the best catalytic performance with an initial propane conversion of 36% and a deactivation rate constant (kd) of 0.0127 h-1. The XPS results indicate that the electronic properties of Pt and SnOx are affected not only by their interaction but also by the interaction with support. After a careful analysis of the oxygen storage capacity and activity in CO oxidation, it is hypothesized that the interaction between Pt and Sn becomes stronger following the order:PtSn/B-ZrO2-9 < PtSn/B-ZrO2-11 < PtSn/B-ZrO2-10. The characterization with TPO and Raman on spent catalysts exhibits that more hydrogen deficient coke forms on the support and less coke deposits on the metal surface of PtSn/B-ZrO2-10. The results reveal that the interaction between Pt and Sn is influenced by their respective interaction with the support and a moderate interaction between the metal species and the support is desired.

Key words: Propane dehydrogenation, Platinum-tin, Propylene, Support, Stability