Olefin oligomerization by main group Ga 3+ and Zn 2+ single site catalysts on SiO 2 .

Autor: LiBretto NJ; Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN, USA., Xu Y; Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN, USA., Quigley A; Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN, USA., Edwards E; Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN, USA., Nargund R; Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN, USA., Vega-Vila JC; Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN, USA., Caulkins R; Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN, USA., Saxena A; Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN, USA., Gounder R; Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN, USA., Greeley J; Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN, USA., Zhang G; Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN, USA. gzhang@dlut.edu.cn.; State Key Laboratory of Fine Chemicals, PSU-DUT Joint Center for Energy Research, School of Chemical Engineering, Dalian University of Technology, Dalian, Liaoning, PR China. gzhang@dlut.edu.cn., Miller JT; Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN, USA. mill1194@purdue.edu.
Jazyk: angličtina
Zdroj: Nature communications [Nat Commun] 2021 Apr 19; Vol. 12 (1), pp. 2322. Date of Electronic Publication: 2021 Apr 19.
DOI: 10.1038/s41467-021-22512-6
Abstrakt: In heterogeneous catalysis, olefin oligomerization is typically performed on immobilized transition metal ions, such as Ni 2+ and Cr 3+ . Here we report that silica-supported, single site catalysts containing immobilized, main group Zn 2+ and Ga 3+ ion sites catalyze ethylene and propylene oligomerization to an equilibrium distribution of linear olefins with rates similar to that of Ni 2+ . The molecular weight distribution of products formed on Zn 2+ is similar to Ni 2+ , while Ga 3+ forms higher molecular weight olefins. In situ spectroscopic and computational studies suggest that oligomerization unexpectedly occurs by the Cossee-Arlman mechanism via metal hydride and metal alkyl intermediates formed during olefin insertion and β-hydride elimination elementary steps. Initiation of the catalytic cycle is proposed to occur by heterolytic C-H dissociation of ethylene, which occurs at about 250 °C where oligomerization is catalytically relevant. This work illuminates new chemistry for main group metal catalysts with potential for development of new oligomerization processes.
Databáze: MEDLINE
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