Direct preparation of Zr-SBA-15 microspheres and their catalytic performance on methanol dehydration

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, TEMEDS, 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.