催化学报

催化学报 ›› 2009, Vol. 30 ›› Issue (10): 1041-1048.

• 研究论文 • 上一篇    下一篇

镧改性的CuHY分子筛中铜离子的分布及其对吸附脱硫性能的影响

范闽光 1, 李斌 1, 张飞跃 1, 方金龙 1, 李望良 2, 邢建民 2, 刘自力 1   

  1. 1 广西大学化学化工学院, 广西南宁 530004 2 中国科学院过程工程研究所, 北京 100871
  • 收稿日期:2009-10-25 出版日期:2009-10-25 发布日期:2013-06-06

Distribution of Cu Ions in Lanthanum-Modified CuHY Zeolite and Its Influence on Adsorption Desulfurization Performance

FAN Minguang1, LI Bin1,*, ZHANG Feiyue1, FANG Jinlong1, LI Wangliang2, XING Jianmin2, LIU Zili1   

  1. 1College of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, Guangxi, China 2Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100871, China
  • Received:2009-10-25 Online:2009-10-25 Published:2013-06-06

PDF

873

被引次数

13

摘要： 在氮气气氛下采用等体积浸渍法制备了载 Cu 的 HY 和 LaHY 分子筛. 用 X 射线衍射 (XRD)、N2 吸附、氨程序升温脱附和 X 射线光电子能谱对分子筛进行了表征. 通过多晶 XRD 确定了 Cu2+离子在 Y 型分子筛笼内的结构与分布, 并测定了分子筛在含二苯并噻吩 (DBT) 的模拟柴油中的吸附脱硫性能. 结果表明, 前驱体 CuCl2 中的大部分 Cu 物种与 HY 和 LaHY 分子筛进行了离子交换. 对于 La3+改性的 CuHY 分子筛 (CuLaHY), 进入分子筛超笼中的 Cu2+离子与骨架氧和水分子配位, 牢固地定位于 Y 型分子筛超笼的 SII 及 SIII 位; 对于 CuHY 分子筛, 超笼中的 Cu2+离子只接近于 SII 及 SIII 位. 极少部分 CuCl 分子高度分散在分子筛笼内, 没有定位. 处于超笼中 SII 及 SIII 位的 Cu2+离子对模拟柴油中的 DBT 分子具有吸附作用, 是吸附脱硫的活性中心. CuLaHY 分子筛的吸附脱硫性能优于 CuHY 分子筛. 当模拟柴油中含有萘时, 萘与 DBT 分子会产生竞争吸附.

关键词: HY 分子筛, 铜, 镧, 吸附剂, 修饰, 二苯并噻吩, 吸附脱硫

Abstract: The Cu-loaded CuHY and CuLaHY zeolites were prepared by an incipient wetness method under nitrogen gas atmosphere. The samples were characterized by X-ray diffraction (XRD), N2 adsorption, NH3 temperature-programmed desorption, and X-ray photoelectron spectroscopy. The crystalline structure and the distribution of Cu2+ cations in the cages of Y zeolite were determined by XRD. The adsorption desulfurization performance of the zeolites was investigated for model diesel containing dibenzothiophene (DBT). The results showed that most of Cu species from the precursor CuCl2 was ion-exchanged with the HY and LaHY zeolites. For the La3+-modified CuHY zeolite (CuLaHY), the Cu2+ cations entering the supercages of the zeolite coordinated with both skeleton-oxygen atoms and water molecules, and thus being firmly situated at the sites SII and SIII in the supercages. For the CuHY zeolite, however, Cu2+ cations entering the supercages were only near the sites SII and SIII in the supercages. A very small percentage of CuCl molecules was highly scattered in the cages of the Y zeolite, with no definite position. The Cu2+ cations at the sites SII and SIII in the supercages adsorbed DBT molecules in the model diesel were the centers of adsorption desulfurization. The desulfurization capacity of the CuLaHY zeolite was better as compared with the CuHY zeolite. However, naphthalene molecules will result in competitive adsorption with DBT molecules if there are naphthalene molecules in the model diesel.

Key words: HY zeolite, copper, lanthanum, adsorbent, modification, dibenzothiophene, adsorption desulfurization