Identification of the structure of Ni active sites for ethylene oligomerization on an amorphous silica-alumina supported nickel catalyst

The structure of Ni active sites supported on amorphous silica-alumina supports with different contents Al2O3 loadings in relation to their activities ethylene oligomerization were investigated. Two kinds detected by situ FTIR-CO and H2-TPR experiments, that are Ni2+ cations as grafted weak acidic silanols at ion-exchange positions. these Ni/ASA catalysts found an ascending tendency the loading decreased, which could be attributed enriched concentration species a weaker interaction support. These more easily evolved into Ni+ species, has been identified oligomerization. Thus, it seems reasonable conclude precursors sites.