高等学校化学学报 ›› 2020, Vol. 41 ›› Issue (6): 1208-1217.doi: 10.7503/cjcu20200076

• 庆祝《高等学校化学学报》复刊40周年专栏 • 上一篇    下一篇

高比表面积等级孔γ-Al2O3的金属醇酯一步水解法制备及性能

刘思明1,汪建南1,余申1,刘湛1,王朝1,李小云2,陈丽华1,*(),苏宝连1,*()   

  1. 1. 武汉理工大学, 材料复合新技术国家重点实验室, 武汉 430070
    2. 硅酸盐建筑材料国家重点实验室, 武汉 430070
  • 收稿日期:2020-02-17 出版日期:2020-06-10 发布日期:2020-03-12
  • 通讯作者: 陈丽华,苏宝连 E-mail:chenlihua@whut.edu.cn;su@unamur.be
  • 基金资助:
    国家自然科学基金(21805216);国家自然科学基金(21902122);国家博士后科研基金(2019M652723)

Preparation of High-surface-area Hierarchically Porous γ-Al2O3 by One-step Hydrolysis of Metal Alkoxide and Performance

LIU Siming1,WANG Jiannan1,YU Shen1,LIU Zhan1,WANG Zhao1,LI Xiaoyun2,CHEN Lihua1,*(),SU Baolian1,*()   

  1. 1. State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan 430070, China
    2. State Key Laboratory of Silicate Material for Architectures, Wuhan University of Technology, Wuhan 430070, China
  • Received:2020-02-17 Online:2020-06-10 Published:2020-03-12
  • Contact: Lihua CHEN,Baolian SU E-mail:chenlihua@whut.edu.cn;su@unamur.be
  • Supported by:
    † National Natural Science Foundation of China(21805216);National Natural Science Foundation of China(21902122);Postdoctoral Science Foundation of China(2019M652723)

摘要:

采用金属醇酯一步水解法, 在不同含水有机溶剂反应介质中在常温条件下制备了具有特殊形貌及等级孔道结构的超高比表面积γ-Al2O3材料. X射线衍射(XRD)、 N2吸附-脱附、 扫描电子显微镜(SEM)和透射电子显微镜(TEM)等表征结果证明, 通过调节反应介质中水含量和溶剂类型可以精确控制仲丁醇铝的水解缩合反应过程和副产物醇分子的扩散行为, 进而优化产物的孔道结构. 研究结果表明, 在水/乙腈体系下制备的γ-Al2O3材料整体呈现出由大孔直孔道和三维介孔孔道构成的等级孔道结构, 且随着水含量的增加, 大孔孔壁依次出现光滑状、 片状和褶皱状的特定形貌; 在饱和水的丁醇溶液体系下制备的材料则展现出由厚度约为10 nm的片状γ-Al2O3堆积而成的三维介孔结构, 比表面积高达517 m 2/g. 选取水含量为3 mL的水/乙腈体系下的大孔-介孔γ-Al2O3材料作为载体制备负载型Pt基催化剂. 负载后载体等级孔结构基本保持完好, 金属Pt纳米颗粒均匀分散在载体上, 该催化剂在渣油脱金属催化反应中的脱金属性能比商用薄水铝石为载体制备Pt基催化剂更加优异. 脱Ni率和脱V率分别提高11.62%和10.83%.

关键词: 金属醇酯一步水解, 等级孔结构, 催化剂, 渣油加氢, 脱金属

Abstract:

Ultrahigh-surface-area γ-Al2O3 materials with special morphologies and hierarchically porous structures were prepared at room temperature by one-step hydrolysis of metal alkoxide under different aqueous organic solvents systems. With the aid of X-ray diffraction(XRD), N2 adsorption-desorption, scanning electronic microscopy(SEM) and transmission electron microscope(TEM), it was proved that the hydrolysis and condensation process of aluminum tri-sec-butoxide and the diffusion behavior of by-product alcohol molecules could be precisely controlled by the water content and the type of solvent, thereby the product structure were optimized in return. The results show that the γ-Al2O3 material with straight macroporous wall and 3D-mesporous was obtained under the water/acetonitrile system, meanwhile, the smooth, flaky and wrinkled morphologies appeared in the macroporous wall in turn as the water content increased. However, only 3D-mesporous structure stacked with 10 nm-thick flaky γ-Al2O3 could be observed for the material prepared under the saturated butanol solution system with the specific surface area of up to 517 m 2/g. Besides, the macro-mesoporous γ-Al2O3 material prepared under the 3 mL water content in the water/acetonitrile system was selected as the carrier for Pt-based catalyst. The carrier structure basically remained intact after the loading process and metal Pt nanoparticles were uniformly dispersed on the carrier. The hierarchical γ-Al2O3 supported Pt-based catalyst showed better hydrodemetallization performance than the commercial boehmite supported catalyst, and the Ni and V removal rate increased by 11.62% and 10.83%, respectively.

Key words: One-step hydrolysis of metal alkoxide, Hierarchically porous structure, Catalyst, Residual oil hydrogenation, Demetallization

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