Ni-S₂O₈^2-/ZrO₂-Al₂O₃ Solidsuperacid Catalysts Preparation And Isomerization Performance Study

With the development of modern industry, the demand for high quality fuel became more and more high. High octane fue can effectively reduce the detonation phenomenon and reduce the automobile exhaust pollution to the environment. Alkanes isomerization is the most effective way to improve the quality of gasoline, so which has practical significance. Beacause of good isomerization performance at low temperature, SO42-/Mx Oy solid superacid atttacted much attention of the reserchers. With development of the research,people found that S2O82-/Zr O2 solid superacids have higher acidity and stability than SO42-/Mx Oy solid superacid,beside that it has many advantages,such as the simple preparation process, high activity, repeatable use,especially good alkanes isomerization performance, which makes it a potential and environmental friendly catalyst in petrochemical industry field.In the study,we prepared Ni-S2O82-/Zr O2-Al2O3-La2O3 and Ni-S2O82-/Zr O2-Al2O3 by different methods,n-heptane isomerization as a probe reaction,reseach the behavior of them.we prepared Ni-S2O82-/Zr O2-Al2O3 catalyst by sol-gel method.Though the sol-gel process template agent(P123) can reduce the destroy of water,s interfacial rension to Zr O2, inhibit Zr(OH)4 excessive condensation, adjust the pore structure and the size of Zr O2, make the catalyst particle size small, improve the specific surface area and entrance crystal shape.When the content of Ni and Al was 5%,La content was 2%, n(P123)/n(Zr) = 0.03,(NH4)2S2O8 impregnation concentration was 0.75 mol/L,calcination temperature is 650°C, reduction temperature was 400 ℃, reduction time was 4 h, the reaction temperature was 240 ℃,the conversion of n-heptane isomerization was 51.38% and the selectivity of n-heptane isomerization was 76.13%.we prepared Ni-S2O82-/Zr O2-Al2O3-La2O3 modified by rare earth La.It,s crystal structure and pore parameter were deterrnined by XRD,BET,IR.The catalytic performance of n-heptane isomerization under different conditions.The results showed that introduction of La, the catalytic got stable catalyst crystal type, and its specific surface area increased, isomerization performance improvement.Under the condition thatthe content of Ni and Al was 5%,La content was 2%, n(P123)/n(Zr) = 0.03,(NH4)2S2O8 impregnation concentration was 0.75 mol/L,calcination temperature is 650°C, reduction temperature was 400 ℃, reduction time was 4 h, the reaction temperature was 240 ℃,the conversion and selectivity of n-heptane isomerization was 63.52% and 80.29%.