孔径可调的介孔磷酸铈的合成

Synthesis of mesoporous cerium phosphate with controllable pore size

采用中性表面活性剂十八胺为模板剂、硫酸铈为铈源,在水热条件下合成具有介孔结构的磷酸铈。通过X-射线衍射、透射电镜、高倍透射电镜和液氮吸附手段对介孔磷酸铈的介观结构、微观形貌和孔道结构进行了表征。结果表明,该材料是的有序的层状相介孔,层间距为2~3 nm。产物主晶相为结晶性良好的单斜晶系的独居石磷酸铈,次晶相为正交晶系的磷酸铈。调整无机铈源与表面活性剂的摩尔比,实现磷酸铈介孔孔径在5.5~9.8 nm之间可调。该介孔材料的最大比表面积高达113 m2/g,孔体积为0.25 mL/g。

Under hydrothermal condition,cerium(Ⅳ) sulfate was used as a cerium source,octadecylamine(C18H37NH2)as molecular template,and lamellar well-aligned mesostructrue of the monazite cerium phosphate was successfully synthesized.Small and large X-ray diffraction(XRD),transmission electron microscopy(TEM),high-resolution transmission electron microscopy(HRTEM) and nitrogen physisorption analysis were used to characterize the mesostructrure,skeletal microstructure and pore structrue.The results showed that the interlayer spacing of mesostructure CePO4 was around 2-3 nm.The main crystalline phase of the product was monazite CePO4,the second crystalline phase was Ce(PO3)4.By controlling the rate of cerium sulfate and octadecylamine of the reactive system,pore size of the mesostructure CePO4 varied from 5.5 nm to 9.8 nm.The maximal surface area of mesoporous CePO4 was 113 m2/g,corresponding to pore volume of 0.25 mL/g.