纳米SnO_2高效催化烯烃与H_2O_2环氧化反应研究

Nano-SnO_2 as Highly Efficient Catalyst for Epoxidation of Cyclic Olefins with Aqueous H_2O_2

构建了用于催化烯烃与过氧化氢环氧化反应的高效、绿色催化反应体系.首先,通过水热合成法制备了纳米SnO_2,并在320℃下煅烧.随后,对所有催化剂进行X射线衍射(XRD)、紫外-可见漫反射光谱(UV-Vis)、傅里叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)表征.进一步将催化剂用于以H_2O_2水溶液为氧化剂环氧化各种官能化烯烃(包括环烯烃,苯乙烯和直链烯烃)的反应,以高转化率和高选择性得到了环氧化物.在相似的反应条件下,发现合成的纳米SnO_2-170催化剂在催化1-甲基环己烯与H_2O_2的环氧化反应中的活性最佳,在2 h内1-甲基环己烯的转化率达到100%,环氧化物选择性达到100%.

A green catalytic reaction system with characteristic of high efficiency for the synthesis of epoxides by catalytic epoxidation of functionalized olefins with hydrogen peroxide was constructed. SnO2 nanoparticles were prepared by hydrothermal synthesis method and calcined at 320℃. Subsequently, all catalysts were characterized by X-ray diffraction(XRD), UV-Vis diffuse reflectance spectroscopy(UV-Vis), Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy(SEM) and transmission electron microscopy(TEM). Then, these catalysts were used to catalyze the epoxidation of various functionalized olefins, including cyclic olefins, styrene and linear olefins, using H2O2 aqueous solutions as oxidants, with high conversion for olefins and high selectivity to epoxides. Under similar reaction conditions, thus-synthesized nano-SnO 2-170 catalyst was found to be the most active one in the epoxidation of 1-methyl cyclohexene with H2O2, for which 100% of conversion and 100% selectivity were achieved within 2h.