物理化学学报 >> 2012, Vol. 28 >> Issue (06): 1467-1473.doi: 10.3866/PKU.WHXB201203312

催化和表面科学 上一篇    下一篇

CuO-SBA-15的表面酸性对燃料油吸附脱硫的影响

邵新超1, 段林海1, 武玉叶1, 秦玉才2, 于文广1, 王源1, 李怀雷1, 孙兆林1, 宋丽娟1,2   

  1. 1. 辽宁石油化工大学, 辽宁省石油化工催化科学与技术重点实验室, 辽宁抚顺 113001;
    2. 中国石油大学(华东)化学化工学院, 山东青岛 257061
  • 收稿日期:2012-02-27 修回日期:2012-03-29 发布日期:2012-05-17
  • 通讯作者: 宋丽娟 E-mail:lsong56@263.net
  • 基金资助:

    国家自然科学基金(20976077, 21076100), 国家重点基础研究发展规划项目(973) (2007CB216403)及辽宁省高校创新团队资助

Effect of Surface Acidity of CuO-SBA-15 on Adsorptive Desulfurization of Fuel Oils

SHAO Xin-Chao1, DUAN Lin-Hai1, WU Yu-Ye1, QIN Yu-Cai2, YU Wen-Guang1, WANG Yuan1, LI Huai-Lei1, SUN Zhao-Lin1, SONG Li-Juan1,2   

  1. 1. Key Laboratory of Petrochemical Catalytic Science and Technology, Liaoning ShiHua University, Fushun 113001, Liaoning Province, P. R. China;
    2. College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao 257061, Shandong Province, P. R. China
  • Received:2012-02-27 Revised:2012-03-29 Published:2012-05-17
  • Contact: SONG Li-Juan E-mail:lsong56@263.net
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20976077, 21076100), National Key Basic Research Program of China (973) (2007CB216403), and Innovation Team of Liaoning Province Colleges, China.

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摘要： 固相研磨法是将不同量的活性组分掺入到介孔材料上的一种简单有效的方法. 采用该法以焙烧脱模前后的SBA-15为载体分别制备了不同负载量的CuO-SBA-15吸附剂. 利用X射线衍射(XRD)、N2物理吸附、傅里叶变换红外(FTIR)等方法表征了吸附剂的物理性质. 通过原位红外技术考察了改性前后介孔材料表面羟基的变化. 借助吡啶-原位傅里叶变换红外(py-FTIR)技术考察了吸附剂表面的酸类型及相对酸量. 采用静态吸附实验评价了吸附剂对催化裂化(FCC)燃料油的吸附脱硫性能. 结果表明: CuO是与SBA-15 表面的Si―OH结合形成[Si-O-Cu-O-Si]交联从而达到分散的目的; 以SBA-15 介孔材料(APS)为载体能够有效抑制在焙烧过程中介孔材料表面羟基的缩合, 且CuO负载量达到3 mmol·g-1时仍能够均匀分散在载体SBA-15上, 而采用焙烧脱模的SBA-15 (CS)为载体制备的CuO-SBA-15 吸附剂却出现了活性组分团聚现象; 吸附剂的酸性与脱硫性能均随着CuO的增加出现先增加后降低的趋势, 当CuO负载量达到3 mmol·g-1时吸附剂具有最高的Lewis 酸(L酸)酸量及最佳的脱硫性能; 吸附剂的L酸酸量与其脱硫性能成正相关关系; 另外吸附剂的L酸的形成是由于改性后Cu周围的电荷密度降低引起的.

关键词: SBA-15介孔材料, 表面酸性, 羟基, 吸附脱硫, Lewis酸

Abstract: Solid-state grinding is a simple and effective technique to incorporate active species into the channels of mesoporous materials with different degrees of filling. Using this method, different concentrations of CuO were loaded into the mesochannels of as-prepared mesoporous silica (APS) and calcined SBA-15 (CS). The samples were prepared and characterized using X-ray diffraction (XRD), N2 physisorption, and Fourier transform infrared (FTIR) spectroscopy. The relative number of hydroxyl groups was studied by in situ FTIR spectroscopy, and the total surface acidity of the adsorbents was monitored by FTIR spectroscopy at 423 K using pyridine as a probe. Desulfurization of fluid catalytic cracking (FCC) fuel oils using these materials was investigated. The results suggest that CuO interacts directly with support hydroxyl groups to form [Si-O-Cu-O-Si] linkages in the mixtures, which can effectively constrain the condensation of hydroxyl groups in SBA-15 to improve the mesostructure of the adsorbents during calcination. Saturated coverage of the surface of APS is reached using 3 mmol·g-1 CuO. However, using CS, aggregation of CuO is observed in the material containing 3 mmol·g-1 of CuO. Both the surface acidity and desulfurization performance significantly increase upon modification of SBA-15 with CuO, and then decrease slowly as the concentration of CuO is increased. The sample containing 3 mmol·g-1 CuO shows the highest Lewis acidity and desulfurization performance. The Lewis acidity of the adsorbents matches the adsorptive desulfurization performance. It is also demonstrated that reduction of charge density around copper atoms helps to form Lewis acid sites.

Key words: SBA-15 mesoporous material, Surface acidity, Hydroxyl group, Adsorptive desulfurization, Lewis acid