Study On The Preparation, Characterization And Catalytic Performance Of SO₄^2-/Hangjin2^# Clay

In this paper, three different granularity of Hangjin2^# clay were prepared and characterized. SO₄^2-/Hangjin2^# clay, Hangjin2^# clay-Fe₂O₃, SO₄^2-/Hangji- n2^# clay-Fe₂O₃ were prepared using Hangjin2^# clay which contained the most clay and iron oxide, then the mineral composition, structure and acidity were characterized by XRF, FT-IR, XRD, BET, UV and the catalytic performance was studied on the cyclohexanol dehydration model reaction. The influence of the content of iron oxide and the preparation conditions to the physical and chemical properties of SO₄^2-/ Hangjin2^# clay were studied and discussed.The results showed that:1. "500mu" Hangjin2^# clay contains the highest content of palygorskite, illite, chlorite and iron oxide which are relatively stable, shows weak acidity, which is relation to the interaction of clays, but not to the content of iron oxide .2. The acidity of SO₄^2-/Hangjin2^# clay preparing by "500mu", "250mu ","Original Clay" is stronger than the corresponding carriers, and the SO₄^2-/ Hangjin2^# clay preparing by "500mu"clay shows the strongest acidity.3. The studies on the preparing condition of SO₄^2-/Hangjin2^# clay show that: the influence of acidification time and solid-liquid ratio is weak, but of sulfuric acid concentration and calcined temperature is strong. Under acidif- ication time of 24h, solid-liquid ratio of 1:5, sulfuric acid concentration of 1.0mol/L, calcined temperature of 300℃, the SO₄^2-/Hangjin2^# clay shows the largest surface acidity and surface area, and the yield of cyclohexene can up to 75%. The SO₄^2-/ Hangjin2^# clay also certains a few CaSO4 and some SiO2, Al2O3, Fe₂O₃, MgO and K2O, and remains the crystal structure of correspond- ing carrier.4. The studies on SO₄^2-/Hangjin2^# clay-Fe₂O₃ show that: the increase of the content of iron oxide can not strenghen the surface acidity and catalytic performance of SO₄^2-/Hangjin2^# clay-Fe₂O₃, but the surface acidity of SO₄^2-/ Fe₂O₃ is strong. When sulfuric acid concention of 1.0 mol/L, calcined temperature of 450℃⁵00℃, the SO₄^2-/Fe₂O₃ shows the largest surface acidity and existences crystal structure ofα-Fe₂O₃. Meanwhile the SO₄^2-/ Fe₂O₃ existences superacid structure which characterized by the infrared spectrum of absorption pyridine, but shows poor catalytic performance on preparing cyclohexene. The probable reason is that SO₄^2-/Fe₂O₃ displays stronger oxidation.