以十六烷基三甲基溴化铵和聚苯乙烯微球乳液为混合模板剂,采用水热法合成MoO3-ZrO2复合型氧化物。采用扫描电镜(SEM)、透射电镜(TEM)、N2吸附-脱附、X射线衍射(XRD)和吡啶吸附原位红外光谱(Py-IR)对不同焙烧温度制备的MoO3-ZrO2进行表征。以正己烷异构化反应为探针,采用小型固定床反应器评价了MoO3-ZrO2异构化催化活性。结果表明,焙烧温度对MoO3-ZrO2的晶相结构、表观形貌、织构性能及酸中心的影响显著。当焙烧温度为700℃时,催化剂主要以四方晶相ZrO2形式存在,样品表面光滑、孔隙发达,呈现出包含大孔和无序堆积介孔的多孔结构,具有最适宜的比表面积和超强酸量,同时表现出较高的异构化催化活性,其正己烷异构化转化率为48.6%,异构体的选择性为70.2%。
MoO3-ZrO2composite oxide was prepared by hydrothermal synthesis method with cetyltrimethylammonium bromide and polystyrene microsphere emulsion as mixture templates. The MoO3-ZrO2synthesised at different calcination temperatures were characterized by scanning electron microscopy (SEM), transmission electron microscopy(TEM), N2adsorption-desorption, X-ray diffraction (XRD) and pyridine adsorption infrared spectroscopy (Py-IR). Taking n-hexane isomerization reaction as a probe, the hydroisomerization catalytic performance of MoO3-ZrO2was investigated in a small fixed-bed reactor. The results showed that calcination temperature had significant influence on crystalline structure, apparent morphology, texture properties and acid-centric of MoO3-ZrO2. The MoO3-ZrO2calcined at 700 was mainly in the form of tetragonal ZrO2with smooth surface and developed porosity, showing a porous structure with macropores and disorderly piled mesopores, and having suitable surface area and super acid amount. It also exhibited higher catalytic activity in n-hexane isomerization with the conversion of 48.6% and the i-hexane selectivity of 70.2%, respectivly. ? 2016, Science Press. All right reserved.