论文部分内容阅读
制得了纯净的单斜和四方晶形ＺｒＯ２．给出了制取单一晶形的条件：ｐＨ值保持在９．５左右能够生成单斜晶形ＺｒＯ２；四方晶形ＺｒＯ２的生成需要ｐＨ≥１１．５．催化反应结果表明，晶形对异丁烯的选择性有着重要的影响．单斜晶形ＺｒＯ２有利于异丁烯的生成；四方晶形ＺｒＯ２使异丁烯的生成量显著降低．不同方法制备的ＺｒＯ２催化性能有所不同．超临界流体干燥法制得的ＺｒＯ２催化剂的活性和产物选择性均高于其它方法．文中对此反应的机理进行了讨论．
Pure monoclinic and tetragonal ZrO2 were obtained. The conditions for preparation of a single crystal are given: monoclinic ZrO2 can be formed by keeping the pH at about 9.5; and the formation of tetragonal ZrO2 requires pH ≥11.5. The catalytic reaction results show that the crystal form has an important influence on the selectivity of isobutylene. Monoclinic ZrO2 is conducive to the formation of isobutylene; tetragonal ZrO2 so that the formation of isobutene significantly reduced. The catalytic performance of ZrO2 prepared by different methods is different. ZrO2 catalysts prepared by the supercritical fluid drying method have higher activity and product selectivity than other methods. The reaction mechanism is discussed in this paper.