Effects of phosphorous promoters on catalytic performance for oligomerization of butene over Ni-based catalysts

In order to evaluate the potential of C₄ raffinate II as a feedstock for oligomerization reactions, the effects of 1,3-butadiene in C ₄ raffinate II on catalyst life were tested over Ni/Al ₂O₃ catalysts in a fixed bed reactor. Catalytic deactivation by butadiene in the oligomerization of industrially produced C ₄ raffinate II could be mitigated by a reduction of 1,3-butadiene content, from 0.15 to 0.004wt.%, through selective hydrogenation. To improve catalytic performance, phosphorous compounds were adapted as a promoter for the Ni/Al₂O₃ catalyst and octene selectivity was enhanced. The branching index of the product over the Ni-P-triphenyl phosphine oxide/Al ₂O₃ catalyst is higher than that over other catalysts, which is desirable for the production of octenes as a raw material for gasoline blending.