Acta Phys. -Chim. Sin. ›› 2014, Vol. 30 ›› Issue (9): 1736-1744.doi: 10.3866/PKU.WHXB201407091

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Selective Oxidation of Ethane to Aldehydes over Potassium-Promoted SBA-15-Supported Molybdenum Oxide Catalysts

LI Jian-Mei, LIU Jian, REN Li-Wei, LIU Qing-Long, ZHAO Zhen, WEI Yue-Chang, DUAN Ai-Jun, JIANG Gui-Yuan   

  1. State Key Laboratory of Heavy Oil, College of Science, China University of Petroleum, Beijing 102249, P. R. China
  • Received:2014-04-16 Revised:2014-07-08 Published:2014-08-29
  • Contact: LIU Jian, ZHAO Zhen E-mail:liujian@cup.edu.cn;zhenzhao@cup.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21376261, 21173270, 21177160), Natural Science Foundation of Beijing, China (2142027), National High-Tech Research and Development Program of China (863) (2013AA065302), and Specialized Research Fund for the Doctoral Program of Higher Education, China (20130007110007).

Abstract:

Potassium-modified SBA-15-supported molybdenum oxide catalysts were prepared using a twostep impregnation method. The physical and chemical properties of the catalysts were characterized using N2- adsorption-desorption, X-ray diffraction (XRD), transmission electron microscope (TEM), UV-visible (UV-Vis) spectroscopy, Raman spectroscopy, NH3 temperature-programmed desorption (NH3-TPD), CO2 temperatureprogrammed desorption (CO2-TPD), and H2 temperature-programmed reduction (H2-TPR). The results showed that potassium addition resulted in the formation of new potassium molybdates, and the states of molybdenum species varied with changes in the K/Mo molar ratio. The addition of potassium to Mo0.75/SBA-15 effectively improved the activity of catalysts and the selectivity to the total aldehydes (formaldehyde, acetaldehyde, and acrolein), especially for acetaldehyde in the selective oxidation of ethane. The turn-over frequency (TOF) and product selectivity depended strongly on the potassium content. The maximum selectivity and yield of aldehydes were obtained by varying the K/Mo molar ratio. At 575 ℃, the maximum yield of aldehydes reached 8.5%(molar fraction) over K0.25-Mo0.75/SBA-15 catalyst. The formation of new potassium-molybdates promoted the activities and selectivities of the catalysts.

Key words: Selective oxidation of ethane, K-modified catalyst, Molybdenum oxide, Aldehyde, SBA-15 mesoporous material

MSC2000: 

  • O643