Abstract
The characterization techniques confirmed the expected SBA-15 structure, with characteristic mesopore ordering and tetrahedral coordinated aluminium in the framework. In batch mode NiSBA-15 proved outstanding behavior in the ethylene oligomerization process: activity up to 180 goligomer/gcatalysth and TOF . These results, which point out the favorable effect of the pore size and architecture, are better than those reported in literature with others Ni-porous materials. The catalytic activity and the product distribution also showed pronounced dependences on the balance between the acid and Ni2+ sites, reaction temperature and pressure. Thus, the ethylene conversion reached a maximum at about 150oC and increases linearly when the pressure increases from 2 to 5 MPa. The oligomeric products were constituted by C4-C12 olefins with traces of C14+ hydrocarbons. A higher acid sites concentration favors further oligomerization of the initial lower olefins and the chain isomerization reaction, resulting in a high concentration of C8+ branched hydrocarbons.