Tungsten Catalyst Incorporating a Well-Defined Tetracoordinated Aluminum Surface Ligand for Selective Metathesis of Propane, [(≡Si−O−Si≡)(≡Si−O−)2 Al−O−W(≡Ct Bu) (H)2 ]
Type
ArticleAuthors
Werghi, Baraa
Bendjeriou-Sedjerari, Anissa
Jedidi, Abdesslem
Morlanes, Natalia Sanchez

Abou-Hamad, Edy
Bhatte, Kushal Deepak

Guan, Erjia
Ma, Tao
Aguilar-Tapia, Antonio
Ould-Chikh, Samy

Cavallo, Luigi

Gates, Bruce C.
Basset, Jean-Marie

KAUST Department
Chemical Science ProgramCore Labs
Imaging and Characterization Core Lab
KAUST Catalysis Center (KCC)
NMR
Physical Science and Engineering (PSE) Division
Technology Transfer
Date
2018-12-21Online Publication Date
2018-12-21Print Publication Date
2019-01-09Permanent link to this record
http://hdl.handle.net/10754/631591
Metadata
Show full item recordAbstract
A well-defined aluminium-bound hydroxyl group on the surface of mesoporous SBA-15, [(≡Si−O−Si≡) (≡Si−O) Al−OH], 3 was obtained by reacting di-isopropyl aluminium hydride with SBA-15 treated at 700 °C. The resulting surface [(≡Si−O−Si≡) (≡Si−O) Al (isobutyl) fragment undergoes β-H elimination at 400 °C leading to [(≡Si−O−Si≡)(≡Si−O−)Al−O) Al−H]. Further oxidation of this Al-hydride with NO leads to 3. This acidic support was used to create a well-defined surface organo-tungsten fragment [(≡Si−O−Si≡)(≡Si−O−)Al−O−W(≡CtBu)(CHtBu)] by reacting 3 with W(≡C-tBu)(CH-tBu). A further reaction with hydrogen under mild conditions afforded the tungsten carbyne bis-hydride [(≡Si−O−Si≡)(≡Si−O−)Al−O−W(H)(≡C-tBu)]. The performance of each of the W-supported catalysts was assessed for propane metathesis in a flow reactor at 150 °C. [(≡Si−O−Si≡)(≡Si−O−) Al−O−W(≡CtBu)(H)] was found to be a single-site catalyst, giving the highest turnover number (TON=800) and the highest reported selectivity for butane (45 %) vs. ethane (32 %) known for oxide-supported tungsten complex catalysts (with the supports being silica, silica-alumina, and alumina). The results demonstrate that modification of the oxide ligands on silica via the creation of Al Lewis acid center as an anchoring site for organometallic complexes opens up new catalytic properties, markedly enhancing the catalytic performance of supported organo-tungsten species.Citation
Werghi B, Bendjeriou-Sedjerari A, Jedidi A, Morlanes N, Abou-Hamad E, et al. (2018) Tungsten Catalyst Incorporating a Well-Defined Tetracoordinated Aluminum Surface Ligand for Selective Metathesis of Propane, [(≡Si−O−Si≡)(≡Si−O−)2 Al−O−W(≡Ct Bu) (H)2 ]. ChemCatChem 11: 614–620. Available: http://dx.doi.org/10.1002/cctc.201801779.Sponsors
The research was supported by the King Abdullah University of Science and Technology and by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Grant DE-FG02-04ER15513. We acknowledge the European Synchrotron Radiation Facility for providing synchrotron radiation facilities. L.C. and A. J. are grateful to the KAUST Supercomputing Laboratory for the resources. A. J. thank High-Performance Computing Center (AZIZ supercomputer) for the support.Publisher
WileyJournal
ChemCatChemAdditional Links
https://onlinelibrary.wiley.com/doi/full/10.1002/cctc.201801779ae974a485f413a2113503eed53cd6c53
10.1002/cctc.201801779