固体超强酸催化剂SO_4^(2-)-MoO_3-ZrO_2中MoO_3的作用与催化性能

Role of MoO_3 in Solid Superacid Catalyst SO_4^(2-)-MoO_3-ZrO_2 and their Catalytic Performance

根据固体超强酸催化剂ＳＯ４２－ －ＭｏＯ３－ＺｒＯ２的特点， 结合活性评价结果， 用ＢＥＴ、ＤＴＡ／ＴＧ、ＸＲＤ、ＬＲＳ等方法， 对其进行了物性表征， 考察了催化剂的结构形态、性质随催化剂组成的变化， 以及催化剂的物性结构特点与催化活性的关系． 研究结果表明， ＭｏＯ３含量对催化剂活性有着显著影响； 催化剂的比表面积随ＭｏＯ３的含量变化存在极大值； ＭｏＯ３具有延迟ＺｒＯ２晶化、稳定ＳＯ４２－ 的作用， 并提高了ＳＯ４２－ 的高温稳定性； 当含量为分散阈值时， 其对催化剂性能的改善作用达到最优， 这时催化剂的催化性能最佳．

In accordance with the catalytic activity evaluation of the solid superacid catalyst SO 4 2- \|MoO 3\|ZrO 2, the catalysts are analyzed and characterized by BET, DTA/TG, XRD and LRS. The structure changes of the catalysts with MoO 3 contents and the relationship between properties and catalytic activity are also investigated. The results show that the MoO 3 content affects the catalytic activity greatly. The surface area of the catalysts changes with the MoO 3 content and has a maximum. MoO 3 has the effects to delay the crystallization of ZrO 2 and to stabilize SO 4 2- . When MoO 3 content is at the dispersing threshold, the improving effects of MoO 3 on the property of the catalysts are optimal, and the catalytic activity is the best.