The silica-supported nickel catalysts with different precursors of NiCl_2, Ni(CH_3COO)_2 and Ni(NO_3)_2 were prepared by sol-gel-SCFD method (hereafter referred to as C-SiO_2, Ac-SiO_2 and N-SiO_2). The physical properties and the structures of catalysts were characterized by TEM, XRD, TPR and IR; the activities of catalytic hydrogenation of maleic anhydride (MA) to succinic anhydride (SA) were examined in liquid phase catalytic hydrogenation process. The results show that the interaction between NiO and SiO_2, the forms and particle size of NiO, and the activities in the catalytic hydrogenation of MA to SA were affected by the precursors used. Compared with Ac-SiO_2 and C- SiO_2, the N-SiO_2 with Ni-O-Si bonds had the smallest NiO clusters and the best dispersion but the lowest hydrogenation activity; however, NiO in Ac-SiO_2 and C-SiO_2 existed as crystallites, the interaction between NiO and SiO_2 decreased in the order of N-SiO_2 > Ac-SiO_2 > C- SiO_2, and the hydrogenation activity increased in the order of C-SiO_2 > Ac-SiO_2 > N-SiO_2. In the case of C-SiO_2, both the hydrogenation activity and selectivity of MA to SA were more than 99%.

Key words: NICKEL OXIDE, SILICON DIOXIDE, GEL, CATALYTIC HYDROGENATION, CATALYTIC ACTIVITY