Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (05): 1169-1175.doi: 10.3866/PKU.WHXB20110502

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Preparation and Catalytic Activities of La2CoAlO6 for Methane Combustion

ZHANG Hui-Min1, HU Rui-Sheng1, HU Jia-Nan1, ZHANG Yu-Long2   

  1. 1. Key Laboratory of Rare Earth Materials Chemistry and Physics, School of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, P. R. China;
    2. Western Research Institute, 365 N 9St, Laramie, Wyoming, USA
  • Received:2011-01-13 Revised:2011-03-03 Published:2011-04-28
  • Contact: HU Rui-Sheng E-mail:cehrs@imu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20763003) and Chun Hui Plans of the Ministry of Education of China (Z2007-1-01029) and Natural Science Foundation of Inner Mongolia, China (2008 0404 MS 0123).

Abstract:

A novel rare earth double perovskite-type catalyst (La2CoAlO6) was prepared by the sol-gel method using citric acid as complex agent. The catalyst was characterized by X-ray powder diffraction (XRD), H2-temperature-programmed reduction (H2-TPR), specific surface area (BET), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, and magnetic property measurement. This catalyst was evaluated for methane combustion. The results showed that a single-phase rare earth double perovskite oxide La2CoAlO6 could be formed by calcination at 1100 °C for 3 h. La2CoAlO6 gives good catalytic activity for methane combustion. It has a light-off temperature (T10) of 434.1 °C and a total conversion temperature (T90) of 657.4 °C. Compared with the single rare earth perovskite-type oxides LaCoO3 and LaAlO3, the T10 decreased by 56.5 and 138.2 °C, and T90 decreased by 84.6 and 108.9 °C, respectively. The FT-IR results indicate that all the synthesized oxides possess perovskite-type structures. Furthermore, the La2CoAlO6 samples showed excellent catalytic activity for methane combustion, which could be related to the decrease in reduction temperature that was observed in the H2-TPR experiments. This was probably because of the increased oxygen mobility that was promoted by the presence of aluminum. In addition, the rare earth double perovskite-type oxide La2CoAlO6 has a platelet morphology and is resistant to sintering. We also found that the double perovskite oxide La2CoAlO6 had special magnetic properties.

Key words: Rare earth, Double perovskite, Single perovskite, Methane catalytic combustion, Sol-gel method

MSC2000: 

  • O643