某些氧化物催化剂上乙醛的气相缩合反应

VAPOUR PHASE ALDOL CONDENSATION OF ACETALDEHYDE CATALYSED BY SOME OXIDE CATALYSTS

某些氧化物催化剂上乙醛的气相缩合反应＊季伟捷陈懿（南京大学化学化工学院化学系，南京２１００９３）关键词乙醛，气相缩合反应，醛酮缩合反应，金属氧化物催化剂在有机化学中缩合反应是很重要的一类形成碳－碳键的反应，由此可以生成许多有用的新化合物．文献报道的催...

Silica supported tungsten oxides (Ⅵ or reduced state) are able to catalyse the vapour phase aldol condensation of acetaldehyde with a good selectivity (especially at higher temperature) and stability, however, the activity is a little bit lower. Variation of the surface structure and acid base properties did not affect the catalytic behavior much for this kind of samples. ZrO 2 is initially quite active but its deactivation is fast. The super acidic sites presented on ZrO 2 SO 2- 4 strongly favor the coke formation but have little contribution to the aldolization. Co feeding hydrogen enhanced the activity of the H 2 pretreated ZrO 2. The S 2- species on ZrO 2, obtained by pre reduction of ZrO 2 SO 2- 4, can promote the aldolization process. The presence of hydrogen could modify the surface of ZrO 2, stablize the state of S 2- species on ZrO 2 surface and inhibit the coke formation and self poisoning.