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以淀粉为生物模板,LDHs晶核溶液为前驱体,通过共沉淀法、陈化及煅烧过程,制备了一系列复合金属氧化物多孔材料.采用X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线能谱(EDX)、N2吸附-脱附(BET)和X射线光电子能谱(XPS)等手段对样品进行形貌、结构与化学组成的表征,并比较它们H2O2-α-蒎烯催化氧化性能.结果表明,淀粉以“嵌入”式发挥模板作用制备出具有独特形貌、孔径分布在约2~5 nm的介孔及大孔尺寸的多金属复合氧化物多孔材料,其比表面积达760.90 m2/g,具有良好的结晶度;其中Mg Zn Al Fe四元复合氧化物催化性能最佳,在α-蒎烯/H2O2摩尔比为1∶1.2、催化剂用量为10.0 mg、溶剂(V(DMF)∶V(水)=4∶1)2 m L、20℃下反应4 h时,α-蒎烯转化率可达53.8%,产物2,3-环氧蒎烷、马鞭草烯醇、马鞭草烯酮的选择性分别为48.9%、2 9.9%、21.3%.
A series of composite metal oxide porous materials were prepared by coprecipitation, aging and calcination with starch as biological template and LDHs nucleus solution as precursors. X-ray diffraction (XRD), scanning electron microscopy (SEM) , X-ray spectroscopy (EDX), N2 adsorption-desorption (BET) and X-ray photoelectron spectroscopy (XPS) were used to characterize the morphology, structure and chemical composition of the samples. Catalytic oxidation.The results showed that the starch played the role of “embedded ” template to prepare the multi-metal composite oxide porous material with unique morphology and mesopore and macropore size distribution about 2 ~ 5 nm, The specific surface area is 760.90 m2 / g, and has good crystallinity. Among them, the quaternary composite oxides of Mg, Zn, Al, Fe have the best catalytic performance with the molar ratio of α-pinene to H2O2 being 1: 1.2, the amount of catalyst being 10.0 mg, (V (DMF): V (water) = 4: 1) 2 m L, the conversion of α-pinene reached 53.8% after reaction at 20 ℃ for 4 h. The product 2,3-epoxy pinane, verbena The enol and verbenone selectivity were 48.9%, 29.9% and 21.3%, respectively.