Oligomerization of ethylene to linear α-olefins catalyzed by Versailles/Santa Barbara-1 with LiAlH4

Abstract

Alkyl-aluminum, which is sensitive to air, has been a major obstacle to the development of ethylene oligomerization. Herein, LiAlH₄ is used as an effective alkyl-aluminum substitute. The performance of LiAlH₄ itself in the reaction is investigated, proving that it possesses moderate activity. Further addition of Versailles/Santa Barbara-1 (VSB-1) catalysts with different morphologies can effectively improve the reaction, in which VSB-1/LiAlH₄ presents the activity of 32.1 g_‧g_LiAlH4⁻¹·h⁻¹ (154.1 g_‧g_VSB-1⁻¹‧h⁻¹) and the selectivity of 1-butene, 1-hexene and 1-octene in all products could reach 51.4 %, 18.9 % and 7.9 %, respectively. The co-catalytic system is stable and the VSB-1 catalyst therein can be effectively reused at least three times under the suitable treatment conditions. In addition, the product analysis of the co-catalyzed system reveals that the addition of VSB-1 catalyst tended to produce 1-butene, 1-hexene and 1-octene at 20 bar. Based on above result, a possible reaction mechanism is proposed.