Controlled synthesis of mesocrystal magnesium oxide parallelogram and its catalytic performance
Controlled synthesis of mesocrystal magnesium oxide parallelogram and its catalytic performance
复制标题
DOI：
10.1039/c5ce00136f
复制
发表时间：
2015-03
期刊：
影响因子：
3.1
通讯作者：
Xiaoling Zhang;Yajun Zheng;Haijun Yang;Qian Wang;Zhiping Zhang
中科院分区：
文献类型：
--
作者：
Xiaoling Zhang;Yajun Zheng;Haijun Yang;Qian Wang;Zhiping Zhang
以磷酸盐为形态调节剂，以硝酸镁和四氧化二钠为无机源，采用简易沉淀法合成了斜长在7~9μm范围内的介晶氧化镁平行四边形。扫描电子显微镜观察发现，在合成产物的对角线中央有一个峡谷。峡谷是由两侧厚度约为100-150 nm的层状结构自组装形成的。考察了反应条件对产物形貌和组成的影响，考察了磷酸盐种类、加入量和反应温度对产物形貌和组成的影响。结果表明，反应体系中微量磷酸盐物种的引入对产物的形貌随反应温度的变化起着至关重要的作用，而傅立叶变换红外光谱和X射线衍射分析表明，产物的组成几乎不受影响。将合成的介晶氧化镁用于苯甲醛与乙醇的Meerwein-Ponndorf-Verley(MPV)反应，其催化性能优于不含磷物种的氧化镁颗粒。
Mesocrystal magnesium oxide (MgO) parallelogram with lengths of diagonal line in the range of 7–9 μm has been synthesized through a facile precipitation method by using phosphate species as the morphology regulator and Mg(NO3)2 and Na2C2O4 as the inorganic sources. Scanning electronic microscope examination revealed that there is a canyon in the middle of the diagonal line of the as-synthesized products. The canyon resulted from the self-assembly of layer-like structures with a thickness of around 100–150 nm on both sides. To investigate the effect of reaction conditions on the morphologies and components of the resulting products, the types and addition amount of phosphate species and the reaction temperature were studied in detail. The results demonstrated that the introduction of trace amounts of phosphate species in the reaction system played a crucial role in determining the morphologies of the obtained products with variation of reaction temperatures, whereas their components have little been influenced after analyses by Fourier-transform infrared spectroscopy and X-ray diffraction. When as-synthesized mesocrystal MgO was employed as a catalyst in the Meerwein–Ponndorf–Verley (MPV) reaction between benzaldehyde and ethanol, it demonstrated superior performance to MgO particles without the presence of phosphate species.