甲醇与乙醇一步合成异丁醛用CuO-ZnO/Al_2O_3催化剂

CuO ZnO/Al 2O 3 CATALYSTS FOR ONE STEP SYNTHESIS OF ISOBUTYRALDEHYDE FROM METHANOL AND ETHANOL

在ＣｕＯＺｎＯ／Ａｌ２Ｏ３催化剂上，甲醇与乙醇在常压和２１０～３６０℃温度下一步反应合成异丁醛．利用正交设计方法，研究了ＣｕＯＺｎＯ／Ａｌ２Ｏ３体系催化剂组成和制备条件等因素对催化剂催化性能的影响．结果表明，催化剂中ＣｕＯ含量对催化剂的催化活性影响最大，而ＺｎＯ含量则主要影响催化剂对异丁醛的选择性．催化剂制备条件，如沉淀温度、陈化时间等，也不同程度地影响催化剂的催化性能．ＸＲＤ和ＢＥＴ表征结果表明，催化剂的晶相及比表面积与催化剂制备条件直接相关．对异丁醛合成反应机理进行了探讨，认为乙醇主要在ＣｕＯ中心上吸附、脱氢，然后在ＺｎＯ中心上与甲醇缩合、脱水生成异丁醛．

Isobutyraldehyde was synthesized in one step from methanol and ethanol over CuO ZnO/Al 2O 3 catalysts at atmospheric pressure and at temperature range of 210～360℃. The orthogonal method was applied to investigate the chemical composition and the preparation conditions of the catalysts. It was found that the catalytic activity and selectivity of the catalysts strongly depend on CuO content while ZnO might play an important role in the formation of isobutyraldehyde. The catalysts, which were precipitated at higher temperature ( e.g. 80℃) and aged for a longer time (e.g. 2 5 h) seem to be more active and selective. The mechanism for isobutyraldehyde formation was also discussed. CuO might act as active centers. Ethanol is mainly adsorbed and dehydrogenated on Cu centers to acetaldehyde. And then, it is condensated with methanol and dehydrated on ZnO centers to produce isobutyraldehyde.