【摘要】 采用化学共沉淀法制备了SO₄^2-/ZrO₂/Fe₃O₄/TiO₂磁性固体酸,利用X射线衍射、示差扫描量热、M（o|¨）ssbauer谱、透射电子显微镜、NH₃-程序升温脱附、N₂吸附-脱附、磁滞回线等手段对磁性固体酸的结构与性质进行了表征。表征结果显示,磁性基质Fe₃O₄及TiO₂的引入有利于四方晶相ZrO₂（t）的稳定;ZrO₂晶体生长取向于ZrO₂（t）的（101）方向,（101）晶面间距为0.293 nm;M（o|¨）ssbauer谱中双峰的存在表明磁性基质Fe₃O₄的存在;在室温下磁性固体酸具有超顺磁性。以乙酸乙酯的合成为探针反应,考察了SO₄^2-/ZrO₂/Fe₃O₄/TiO₂磁性固体酸催化剂的催化性能,实验结果表明,外加磁场使酯化反应的醋酸转化率提高到92%。更多还原

【Abstract】 Nano magnetic solid acids SO₄^2-/ZrO₂/Fe₃O₄/TiO₂ were prepared by co-precipitation. Obtained samples were characterized by XRD,DSC,M（o|¨）ssbauer,TEM,NH₃-TPD,N₂ adsorptiondesorption and magnetic hysteresis loop.The introduction of TiO₂ and magnetic substrate Fe₃O₄ were beneficial to keep tetragonal crystalline structure of ZrO₂ from transferring to monoclinic form in calcination, ZrO₂ crystals grew along the direction of（101） crystal plane.The interplanar distance of ZrO₂（t）（101） plane were 0.293 nm.M（o|¨）ssbauer results revealed the existence of magnetic substrate Fe₃O₄ particles. Magnetic measurement showed superparamagnetism of solid acid catalyst at ambient temperature.Taking synthesis of ethyl acetate as probe reaction for evaluating the activity of nano magnetic solid acid SO₄^2-/ZrO₂/Fe₃O₄/TiO₂ catalyst,the conversion of acetic acid in the esterification mounted to 92%in external magnetic field and aggregation of nano magnetic solid acid catalyst was avoided.更多还原