Hierarchical flower-shaped hollow MgO (f-MgO) spheres were synthesized through an ethylene-glycol-mediated polyol process via hydrothermal reactions. The structure of f-MgO originates from intermediate flower-shaped Mg glycolate through the Ostwald ripening process. The surface of f-MgO consists of uniform petal-like nanosheets that provide high surface area and excellent accessibility to catalytic sites. Also, the f-MgO microsphere can prevent aggregation and stacking problems of nanosheets and control a surface area for catalytic activity. The morphology and structure of f-MgO were investigated using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The density of basic catalytic sites was derived from CO₂-temperature-programmed desorption measurements. The f-MgO exhibits a basic site density of 0.5134 mmol/g, which is much higher than that of commercial MgO (c-MgO, 0.0288 mmol/g). Experimental results for the fatty acid methyl ester revealed that the catalytic strength of f-MgO as a heterogeneous catalyst for biodiesel production is greater than that of c-MgO. The maximum biodiesel conversion efficiency of f-MgO from canola oil is 93.4%, which is greater than the value of 91.4% for c-MgO.

通过水热反应通过乙二醇介导的多元醇工艺合成了分层的花状空心MgO（f-MgO）球。f-MgO的结构起源于经过奥斯特瓦尔德（Ostwald）成熟过程的中间花形乙醇酸镁。f-MgO的表面由均匀的花瓣状纳米片组成，可提供高表面积和极佳的催化部位可达性。同样，f-MgO微球可以防止纳米片的聚集和堆叠问题，并控制催化活性的表面积。使用X射线衍射，扫描电子显微镜和透射电子显微镜研究了f-MgO的形貌和结构。碱性催化位点的密度源自CO ₂-温度编程的解吸测量。f-MgO的基本位点密度为0.5134 mmol / g，远高于商业MgO（c-MgO，0.0288 mmol / g）。脂肪酸甲酯的实验结果表明，作为生物柴油生产非均相催化剂的f-MgO的催化强度大于c-MgO的催化强度。双低菜籽油中的f-MgO的最大生物柴油转化效率为93.4％，高于c-MgO的91.4％。