【摘要】 通过简单的无模板水热法及煅烧处理成功合成了介孔棒状钴酸锰。采用X射线衍射(XRD)、场发射扫描电镜(FE-SEM)、透射电镜(TEM)、氮气吸附-脱附和X射线光电子能谱(XPS)等手段对材料的晶体结构、表面形貌、孔结构和表面化学组成进行了表征。结果表明,目标产物钴酸锰样品介孔结构形成良好,孔径分布在6 nm。此外,钴酸锰的棒状形貌直径为100～200 nm,长度为2～3μm。相比于其他Co基、Mn基催化剂,钴酸锰被首次应用在苯乙烯环氧化反应中,表现出了极高的催化活性,苯乙烯的转化率达到95.8%,对氧化苯乙烯的选择性为58.2%。而且,在5次循环试验后,催化活性并没有发生明显的改变,进一步证明了催化剂的稳定性。同时,系统研究了主要反应参数(反应时间、反应温度、苯乙烯/叔丁基过氧化氢(TBHP)的物质的量比值)对介孔棒状钴酸锰催化活性的影响。更多还原

【Abstract】 Mesoporous rod-like MnCo₂O₄ was fabricated via a facile template-free hydrothermal method and subsequent calcination. The crystal structure, surface morphology, pore structure and surface chemical composition were characterized by X-ray diffraction（XRD）, field emission scanning electron microscopy（FE-SEM）, transmission electron microscopy（TEM）, N2 adsorption-desorption and X-ray photoelectron spectra（XPS）. Characterization results revealed that, in the target MnCo₂O₄ sample, the mesoporous structure was well-formed, and the pore size distribution was defined in 6 nm. Also, the particular rod-like morphology was obtained in MnCo₂O₄ with diameters of 100～200 nm and a length of 2～3 μm. Based on these, the MnCo₂O₄ sample was firstly used as a heterogeneous catalyst in the epoxidation of styrene. Compared with other Co-based and Mn-based catalysts, it exhibited relatively high catalytic activity, the conversion rate of styrene was 95.8%, and the selectivity of styrene oxide was 58.2%. Moreover, after five cycles, the catalytic activity did not change significantly, further confirming the stability of MnCo₂O₄. Meanwhile, the effects of main reaction parameters（reaction time, reaction temperature, the molar ratio of styrene to tert-butyl hydroperoxide（TBHP）） on the catalytic activity of mesoporous rod-like MnCo₂O₄ were systematically investigated.更多还原