Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (05): 1055-1062.doi: 10.3866/PKU.WHXB201301181

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Kinetics Study of CO Oxidation Reaction over Pt/TiO2 Catalysts

LI Na, CHEN Qiu-Yan, LUO Meng-Fei, LU Ji-Qing   

  1. Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, Zhejiang Province, P. R. China
  • Received:2012-10-31 Revised:2013-01-17 Published:2013-04-24
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21173195).

Abstract:

A series of Pt/TiO2 catalysts were prepared using a deposition-precipitation method and calcined at different temperatures to obtain various Pt particle sizes. The catalysts were tested for catalytic CO oxidation and the kinetics of the reaction was studied. The results showed that the Pt particle size increased with calcination temperature, and that their reactivity for CO oxidation first increased and then decreased with increasing calcination temperature, with the catalyst calcined at 400℃ possessing the highest reactivity. The kinetic investigation revealed that the reaction rate could be described by r=5.4×10-7p CO0.17pO20.36, suggesting that the reaction followed a Langmuir-Hinshelwood mechanism. Meanwhile, O2 chemisorption and infrared (IR) spectroscopy of CO chemisorption on the catalysts were conducted to reveal the relationship between the catalyst structure and its catalytic behavior. It was found that the amount of O2 chemisorption and the intensity of CO chemisorption by IR on the catalysts first increased and then decreased with increasing calcination temperature, which was consistent with the catalytic results and the kinetic equation. This could explain the catalytic behaviors of the catalysts. For example, the highest amounts of chemisorbed O2 and CO were obtained over the Pt/TiO2 calcined at 400℃, which resulted in the highest reactivity. Such an enhancement in reactivity was probably due to the strong interaction between Pt and TiO2 induced by the calcination process.

Key words: CO oxidation, Pt/TiO2, Metal-support interaction, Reaction kinetics, Chemisorption

MSC2000: 

  • O643