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考察了ZrO2 前体的制备方法对WOX /ZrO2 的性质及其正庚烷临氢异构化反应性能的影响 ,同时采用BET、XRD、Py IR等手段对其进行了表征。结果表明 ,ZrO2 前体的制备方法会明显影响ZrO2 前体的比表面积及WOX /ZrO2 催化剂中四方ZrO2 和单斜ZrO2 晶型的比例 ,同时WO3 的分散程度也有差异。单斜ZrO2 太多及WO3 晶型的出现会降低正庚烷临氢异构化反应活性 ;而ZrO2 全部为四方晶型时 ,虽然有利于提高低温反应活性 ,但缺点是裂解选择性太高 ;而当单斜ZrO2 和四方ZrO2 共存 ,但以四方ZrO2 为主 ,且没有WO3 晶型出现时 ,既可保持较高的反应活性 ,同时又具有极高的异构化选择性
The effects of preparation methods of ZrO2 precursor on the properties of WOX / ZrO2 and hydroisomerization of n-heptane were investigated. The properties of WOX / ZrO2 were characterized by BET, XRD and Py IR. The results show that the preparation of ZrO2 precursor obviously affects the specific surface area of ZrO2 precursor and the ratio of tetragonal ZrO2 to monoclinic ZrO2 in WOX / ZrO2 catalyst. Meanwhile, the dispersion degree of WO3 is also different. Too much monoclinic ZrO2 and the appearance of WO3 will reduce the hydroisomerization activity of n-heptane. However, all the tetragonal ZrO2, although conducive to improving the low-temperature reactivity, has the disadvantage that the cracking selectivity is too high; However, when both monoclinic ZrO2 and tetragonal ZrO2 coexist, but tetragonal ZrO2 dominated, and no WO3 crystal appeared, it could maintain high reactivity and possess very high isomerization selectivity