物理化学学报 >> 2014, Vol. 30 >> Issue (9): 1736-1744.doi: 10.3866/PKU.WHXB201407091

催化和表面科学 上一篇    下一篇

钾调变Mo/SBA-15催化剂用于乙烷选择氧化制乙醛

李建梅, 刘坚, 任立伟, 刘清龙, 赵震, 韦岳长, 段爱军, 姜桂元   

  1. 中国石油大学北京理学院, 重质油国家重点实验室, 北京 102249
  • 收稿日期:2014-04-16 修回日期:2014-07-08 发布日期:2014-08-29
  • 通讯作者: 刘坚, 赵震 E-mail:liujian@cup.edu.cn;zhenzhao@cup.edu.cn
  • 基金资助:

    国家自然科学基金(21376261,21173270,21177160),北京市自然科学基金(2142027),国家高技术研究发展计划项目(863)(2013AA065302)及高等学校博士学科点专项科研基金项目(20130007110007)资助

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).

摘要:

采用两步浸渍法制备钾改性的Mo/SBA-15 催化剂. 采用N2吸附,X射线衍射(XRD),透射电镜(TEM),紫外-可见(UV-Vis)吸收光谱,拉曼(Raman)光谱,NH3程序升温脱附(NH3-TPD),CO2程序升温脱附(CO2-TPD),H2程序升温还原(H2-TPR)等手段表征催化剂的物理化学性质. 研究结果表明,在Mo0.75/SBA-15 中添加K之后,有新物种钾钼酸盐生成,并且当K/Mo的摩尔比不同时,钼物种的存在状态也不同. 添加钾之后,催化剂的活性和总醛(甲醛、乙醛、丙烯醛)的选择性均有所提高,并且受钾的添加量影响. 在575 ℃时,在K0.25-Mo0.75/SBA-15催化剂上醛的收率可高达8.5%(摩尔分数).

关键词: 乙烷选择氧化, K改性催化剂, Mo氧化物, 乙醛, SBA-15介孔材料

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