摘要:
在SBA-15的合成体系中直接引入锆原子硝酸盐，用氨水调节体系的pH值到4.0~5.0，通过水热晶化处理后得到一系列不同含量的Zr-SBA-15介孔微球。利用XRD、氮吸附、SEM、TEMEDS、ICP、FT-IR、和漫反射UV-vis 等技术对该材料的组成、结构及形貌进行了表征。结果表明，这种杂化材料具有纳米介孔结构、高比表面积和空心微球等特征，空心微球形貌的形成可能与金属杂原子的引入、溶液pH值的调节有关，锆原子被高效率地引入到纳米介孔结构中，表面酸性与未改性前相比有了显著的提高，随着锆含量的增加，样品结构和表面酸性的变化直接影响着催化剂在甲醇脱水反应中的表现。
Abstract:
A series of Zr-containing SBA-15 mesoporous materials with different zirconium contents were synthesized via adding zirconium nitrate into SBA-15 synthesis solution and adjusting the pH value to 4.0～5.0 with ammonia water. The materials were characterized by XRD, N2- physisorption, SEM, TEMEDS, ICP, FT-IR, and UV-vis DRS. The results indicated that all Zr-SBA-15 samples were endowed with special hollow spherical morphology, nanometer pore structure, high surface area, and improved surface acidity. The formation of hollow mesoporous microspheres could be immediately involved with pH-adjusting treatment and heteroatoms introduction. Compared with the unmodified SBA-15, Zr-SBA-15 displays orderly mesoporous structure and high loading efficiency of heteroatoms inside the siliceous matrix, which remarkably improves the surface acidity and catalytic property. Meanwhile, the performance of these catalyst materials in methanol dehydration is also related with the alteration of surface acidity caused by the introduction of zirconium.
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