Abstract: The NiO/Al2O3 catalysts with 20% NiO loading were prepared by stepwise impregnation method with industrial Al2O3 as support. The sulfided catalysts were characterized by BET, XRD, XPS and TEM. The effect of presulfidation conditions on the selective hydrogenation performance of the catalyst was studied in a 10 mL fixed-bed hydrogenation reactor using toluene/n-heptane solution containing dicyclopentadiene (DCPD) and styrene as the model compound. The results showed that sulfidity increased first and then decreased with the increase of presulfidation temperature in the range of 280 -320 ℃. The optimum presulfidation temperature for NiO/Al2O3 catalyst was 300 ℃. The nickel sulfide grains were small and uniformly dispersed when sulfided at 300 ℃. At 180 ℃, 3.5 MPa, space velocity of 3.5 h-1, H2/oil volume ratio of 400:1, the styrene conversion was 97.32%, DCPD conversion was 94.78%, and DCD selectivity was 76.63%.

Key words: cracking C9, presulfidation, NiO/Al2O3 catalyst, selective hydrogenation