No abstract

Ni/Al 2 O 3 catalysts are the promising substitutes of the Pd/Al 2 O 3 catalysts to selective hydrogenation 1,3-butadiene in fluid catalytic cracking (FCC) C 4 fraction. Preparation conditions have an important influence on the activities of the Ni/Al 2 O 3 catalysts. The experiment results proved that the 20 wt% nickel catalyst, which were calcined at 300 ı C for 2 hours then reduced at 300 ı C for 9 hours, had the highest activity. On the basis of the temperature-programmed reduction (TPR) and x-ray diffraction (XRD) analysis, a reasonable explanation was given. This research provided a good prospect for the industrial application of the Ni/Al 2 O 3 catalysts.

The Ni-based catalysts have more advantages than the most widely used Pdbased catalysts in selective hydrogenating of the butadiene in fluid catalytic cracking (FCC) C 4 fraction. But the selectivity and stability of the Ni-based catalysts aren't good. The sulfuration pretreatment is an effective process to improve the performance of the Ni/Al 2 O 3 catalysts. The sulfuration conditions of the Ni/Al 2 O 3 catalyst have been studied in this article. The results showed the fittest conditions are that the catalyst was in-situ presulfurized for 60 min by the solution of S concentration 0.07 mol/L. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis indicated that the presulfurization declined the Ni crystal dimension.