Synthesis of titania-pillared layered tetratitanate and catalytic application in gas-phase Beckmann rearrangement

In this research work, titania-pillared layered tetratitanate (TiO2-H2Ti4O9) was prepared by a stepwise ions-exchange route, in which n-decylamine as a pre-swelling agent and tetrabutyl titanate as the titanium source for producing titanium oxide pillars. Compared with the other titanium alkoxides, tetrabutyl titanate is relatively cheap, and therefore the present pillaring work is more practicable. Powder XRD, FT-IR, and N-2 adsorption-desorption techniques were employed to investigate the pillaring process and characterize the structure of the titania-pillared layered product. The result indicated that the concentration of titanium-pillaring solution obtained by mixing tetrabutyl titanate, acetic acid, and water affected significantly the pillaring behavior. The present titania-pillared layered product had a large surface area (S-BET = 150.0 m(2) g(-1)) and its layered structure was found to be thermally stable even if up to 723 K. Furthermore, catalytic performances of the titania-pillared layered tetratitanate (TiO2-H2Ti4O9) and TiO2-H2Ti4O9-supported B2O3 in gas-phase Beckmann rearrangement of cyclohexanone oxime were investigated, and the research findings highlighted the titania-pillared layered product as a potential supporter for preparing the supported B2O3 catalyst.