一种新型固体碱高稳定性介孔CaO-ZrO_2的制备及性能

Preparation and property of mesoporous CaO-ZrO_2 solid base with high activity and stability

采用可控的溶胶-凝胶法制备了一种新型的介孔CaO-ZrO2固体碱。小角XRD、TEM、低温氮吸附等分析都表明,该介孔固体碱具有优良的热稳定性,即使在700℃依然能保持介孔特征。CO2-TPD测定发现该材料表面具有3种不同的碱性位,且强碱性位数目随着CaO含量增加而增加。研究还发现该介孔固体碱在甲醇与碳酸丙烯酯反应合成碳酸二甲酯中,表现出良好的活性与稳定性,在线运行120 h后,反应物转化率没有明显下降。

A new solid base, CaO-ZrO2 nanocomposite, was prepared via an appropriate sol-gel process. It was found that such nanostructure greatly improved the basic strength and durability of the solid base catalyst. Temperature programmed desorption of CO2 （CO2-TPD） and X-ray photoelectron spectroscopy （XPS） demonstrated that both weak and strong basic sites coexisted on the surface of CaO-ZrO2 nanocomposite. At the same time, the mesoporous CaO-ZrO2 nanocomposite showed high thermal stability, since X-ray diffraction （XRD）, transmission electron microscopy （TEM） proved that the mesoporous network of this material was preserved base showed remarkable activity and stability in propylene carbonate and methanol. well even up to 700℃. As a result, this novel solid the synthesis of dimethyl carbonate （DMC） from