磁性纳米复合氧化物固体酸催化剂的制备及酯化性能

Preparation of magnetic nanocomposites of solid acid catalysts and their applicability in esterification

固体酸催化剂的无腐蚀、环境友好和可循环使用等特点使其成为无机液体酸的最佳替代物.磁性纳米固体酸具有优于常规固体酸催化剂的催化活性及分离简单的特性.用共沉淀法分别合成了一系列三组分TiO2-Al2O3-Fe3O4(TAF)和CeO2-Al2O3-Fe3O4(CAF)及四组分ZrO2--Al2O3-Fe3O4(ZACF)磁性纳米复合氧化物固体酸催化剂,通过电感耦合等离子体原子发射光谱、比表面积测定、X射线衍射、透射电镜、热重分析和红外光谱等对其进行了表征,并利用酯化反应作为探针反应评价了其催化性能.结果表明,合成的磁性纳米固体酸催化剂在酯化反应中表现出很好的催化活性.

Solid acid catalysts are superior to traditional liquid acids because they are noncorrosive,environmentally benign,and recyclable.In addition,nano-magnetic solid acid catalysts are preferable as they exhibit large specific surface areas together with good acidity and are also readily separated from the post-reaction mixture.Three component nano-magnetic solid catalysts TiO_2-Al_2O_3-Fe_3O_4and CeO_2-Al_2O_3-Fe_3O_4 and a four component catalyst ZrO_2-Al_2O_3-CeO_2-Fe_3O_4 were synthesized by a co-precipitation method and were subsequently characterized by inductively coupled plasma-atomic emission spectroscopy,Brunauer-Emmett-Teller surface area analysis,X-ray diffraction,transmission electron microscopy,and thermal gravimetric analysis.Their catalytic activities were also evaluated in the esterification reaction of acetic acid with n-butanol.The results demonstrated that these rare earth-based magnetic nanocomposites exhibited good catalytic activity.