Accessing Realistic Models for the WO 3 –SiO 2 Industrial Catalyst through the Design of Organometallic Precursors - INSA Toulouse - Institut National des Sciences Appliquées de Toulouse
Journal Articles ACS Catalysis Year : 2015

Accessing Realistic Models for the WO 3 –SiO 2 Industrial Catalyst through the Design of Organometallic Precursors

D. Grekov

Abstract

In order to access realistic models to the industrial olefin metathesis catalyst WO3/SiO2, which is the bigrafted tungsten oxo alkylidene species [(≡SiO)2WO(═CHR)], we targeted the parent bis-alkyl oxo derivative [(≡SiO)2WOR2] prone to carbene formation. Thus, grafting of [WO(CH2EMe3)3Cl] (E = C, 1-Np; E = Si, 1-Ns) onto silica dehydroxylated at 200 °C was performed. While 1-Np affords the monopodal species [(≡SiO)WO(CH2CMe3)3] (2-Np), the neosilyl derivative 1-Ns reacts to yield the well-defined bipodal species [(≡SiO)2WO(CH2SiMe3)2] (2-Ns), via consecutive HCl and SiMe4 release. This was demonstrated by mass balance analysis, elemental analysis, IR, advanced solid-state NMR (1D and 2D 1H, 13C, 29Si, and 17O), and EXAFS. Furthermore, DFT calculations allowed understanding and rationalizing the experimental results regarding grafting selectivity. The material 2-Ns proved to lead to the most stable and efficient supported tungsten oxo catalyst for propene metathesis under dynamic conditions at 80 °C.
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Dates and versions

hal-01968734 , version 1 (03-01-2019)

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Y. Bouhoute, D. Grekov, K. Szeto, N. Merle, A. de Mallmann, et al.. Accessing Realistic Models for the WO 3 –SiO 2 Industrial Catalyst through the Design of Organometallic Precursors. ACS Catalysis, 2015, ACS Catalysis, 6 (1), pp.1-18. ⟨10.1021/acscatal.5b01744⟩. ⟨hal-01968734⟩
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