催化学报

催化学报 ›› 2011, Vol. 32 ›› Issue (9): 1531-1536.DOI: 10.3724/SP.J.1088.2011.10532

• 研究论文 • 上一篇    下一篇

非水溶剂溶胶-凝胶法制备的纳米卤氧化镧在甲烷氧化偶联反应中的应用

侯玉慧, 常刚, 翁维正, 夏文生a, 万惠霖b   

  1. 厦门大学化学化工学院, 固体表面物理化学国家重点实验室, 醇醚酯清洁化工国家工程实验室, 福建厦门 361005
  • 收稿日期:2011-05-26 修回日期:2011-07-18 出版日期:2011-09-09 发布日期:2015-01-24

Nano-lanthanum Oxyhalide Prepared by Nonaqueous Sol-Gel for Oxidative Coupling of Methane

HOU Yuhui, CHANG Gang, WENG Weizheng, XIA Wenshenga, WAN Huilinb   

  1. State Key Laboratory of Physical Chemistry of Solid Surfaces, National Engineering Laboratory for Green Chemical Productions of Alcohols-Ethers-Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China
  • Received:2011-05-26 Revised:2011-07-18 Online:2011-09-09 Published:2015-01-24

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770

被引次数

21

摘要： 采用非水溶剂溶胶-凝胶法制备了具有四方晶体相结构的纳米 LaOX (X = Cl, Br). X 射线粉末衍射和扫描电子显微镜结果表明, 纳米 LaOX 样品的形貌规整、粒径均匀 (平均粒径约为 47 nm). 在甲烷氧化偶联 (OCM) 反应中, 纳米 LaOX 显示出比常规尺度 LaOX 更高的催化活性和 C2 选择性, 且纳米 LaOX 具有良好的稳定性. 此外, 常规尺度下, LaOBr 催化剂活性和 C2 选择性高于 LaOCl; 纳米尺度下, 两催化剂活性相差不大, 但 LaOBr 上 C2 选择性明显更高.

关键词: 纳米, 卤氧化镧, 甲烷氧化偶联, 溶胶-凝胶, 非水溶剂, 低温活化

Abstract: LaOX (X = Cl, Br) nanoparticles with tetragonal crystal structure were successfully prepared via sol-gel approach with non-aqueous solvents. Characterizations by X-ray powder diffraction and scanning electronic microscopy show that the LaOX nanoparticles are regularly in shape and highly uniform in size with an average diameter of about 47 nm. For oxidative coupling of methane (OCM), the nanosize LaOX catalysts have higher methane conversion and C2 selectivity than the LaOX catalysts with conventional size and show good stability in activity and selectivity during the catalyst life test at 650 °C. At conventional size, the methane conversion and C2 selectivity for OCM over the LaOBr catalyst are higher than that over the LaOCl catalyst, and at nanosize, there is not so much difference in methane conversion between LaOBr and LaOCl. However, the C2 selectivity for OCM reaction over LaOBr is significantly higher than that over LaOCl, especially at low temperature.

Key words: nanometer, lanthanum oxyhalide, oxidative coupling of methane, sol-gel, non-aqueous solvent, low temperature activation