A nano-organized ethylene oligomerization catalyst: Characterization and reactivity of the Ni(MeCN)6(BF4)2/[Al]-MCM-41/AlEt3 system

The complex Ni(MeCN)6(BF4)2 has been immobilized on [Al]-MCM-41 (Ni/[Al]-MCM-41) and characterized by X-ray diffraction (XRD), N2 adsorption, transmission electron microscopy (TEM), diffuse reflectance infrared spectroscopy (DRIFTS) and X-ray photoelectron spectroscopy (XPS). The heterogeneized system retains the catalytic properties of its molecular precursor: the immobilized complex associated with AlEt3 is active in heterogeneous phase ethylene oligomerization under mild reaction conditions. The AlEt3/nickel molar ratio Al/Ni has shown to be a fundamental parameter to control the selectivity of the system into 1-butene. Under typical reaction conditions, 313 K and 0.98 MPa of ethylene and Al/Ni molar ratio of 15, selectivities of ca. 84% in 1-butene have been obtained.