Acta Phys. -Chim. Sin. ›› 2004, Vol. 20 ›› Issue (07): 749-754.doi: 10.3866/PKU.WHXB20040717

• ARTICLE • Previous Articles     Next Articles

Studies on Titanium Tartrate Complex Assembled HMS and NaY

Lü Ai-Xia;Fu Zai-Hui;Yin Du-Lin;Xu You-Zhi;Ming Du-Juan;Yang Qing;Yin Dong-Hong   

  1. Institute of Fine Catalysis and Synthesis, Hunan Normal University, Changsha 410081
  • Received:2003-12-10 Revised:2004-03-30 Published:2004-07-15
  • Contact: Fu Zai-Hui

Abstract: Titanium tartrate complex has been successfully grafted onto hexagonal mesoporous silicas (HMS) or encapsulated into microporous NaY zeolite by means of chemically bonding or “ship in bottle” methods. The UV-Vis diffuse reflection spectra confirmed that two kinds of heterogeneous catalysts had very similar Ti sites. The FT-IR confirmed that Ti tartrate could be bound to the surface hydroxyls of HMS, leading to the appearance of a weak band at 960 cm-1 and a ligand's carbonyl band at 1 736~1 744 cm-1 in their spectra; and only a ligand's carbonyl band was observed in the IR spectra of fresh and recycling Ti tartrate encapsulated NaY samples, indicating that Ti tartrate complex could be steadily encapsulated into the super cages of NaY zeolite. In catalyzing the epoxidation of cinnamyl alcohol with tetrabutyl hydroperoxide(TBHP) as an oxidant, the Ti tartrate grafted HMS showed a higher catalytic activity than the Ti tartrate encapsulated NaY, this is mainly due to the former has a higher Ti loading than the latter. As for as their selectivity for the epoxides,the latter (near 100%) was by far better than the former (about 80%),this is perhaps due to the Na+ located in the super cages and the particular microporous structure of NaY can efficiently restrain the by-reaction such as opening, addition and polymerization of the epoxides.

Key words: HMS, NaY, Ti tartrate, Catalytic oxidation, Epoxidation of cinnamyl alcohol