To ascertain the cause of the formation of the induction period during propylene (I) oligomerization and the nature of active centers on Ni ions supported on amorphous aluminosilicates, the interaction of Ni ions with I was investigated with ESR and XPS measurements in a closed recirculation apparatus The induction period was shortened by increasing the pre-evacuation temperature and the reaction them. Ni(II) was reduced to Ni(I) by I, and then the Ni(I) formed unsatd. complexes with I, these complexes being active intermediates in I oligomerization. It is the formation of these complexes that results in the elimination of the induction period.

Key words: REACTION MECHANISM, CATALYST, NICKEL, X-RAY PHOTOELECTRON SPECTROMETRY, ELECTRON SPIN RESONANCE, OLIGOMERIZATION REACTION, OLIGOMERIZATION REACTION, ALUMINUM SILICATE