A way to avoid polymeric side products during the liquid-phase ethylene oligomerization with SBA-15 supported (bpy)Ni(II)Cl-2 heterogeneous catalyst

Abstract

A new series of (bpy)Ni(II) grafted Ni-SBA-15 catalysts was prepared from treating well-defined mesoporous silica SBA-15 (4 nm in diameter) with various concentrations of bpy based ligand (L1) followed by metalation with NiCl2 for ethylene oligomerization. These new heterogeneous catalysts displayed outstanding catalytic activity depending on the loading density of Ni on SBA-15. In other words, 4 (0.21 wt% of Ni) showed much better intrinsic activity towards butene (IA = 3605 +/- 28 mol(product)/mol(Ni)h) than that of 1 (2.25 wt% of Ni; IA = 911 +/- 28 mol(product)/mol(Ni)h), suggesting that the formation of higher molecular weight side products was successfully inhibited by reducing the local concentration of catalyst on mesoporous silica SBA-15.