Dynamic behaviour of tantalum hydride supported on silica or MCM-41 in the metathesis of alkanes
Type
ArticleKAUST Department
Chemical Science ProgramKAUST Catalysis Center (KCC)
Physical Science and Engineering (PSE) Division
Date
2014Permanent link to this record
http://hdl.handle.net/10754/563166
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The metathesis of ethane and propane catalysed by tantalum hydride supported on silica or MCM-41 was studied under static and dynamic conditions. During the reaction, the rate decreased over time, indicating deactivation of the catalyst. The evolution of the catalytic system and surface species over time was monitored by various physico-chemical methods: FTIR, 13C NMR spectroscopy, elemental analysis and chemical reactivity. A carbonaceous deposit composed of unsaturated hydrocarbyl species was observed by 13C NMR. This deposit was responsible for poisoning of the catalyst. The deactivation of the catalyst proved more severe at higher temperatures and under static rather than dynamic conditions. A partial regeneration of the catalyst could be achieved during a series of repeated runs. Mechanistically, the deconvolution of the products' distribution over time indicated the occurrence of hydrogenolysis in the early stages of the reaction, while pure metathesis dominated later on. The hydrogen was supplied by the dehydrogenation of hydrocarbyl surface species involved in the deactivation process. © 2014 The Royal Society of Chemistry.Citation
Soignier, S., Saggio, G., Taoufik, M., Basset, J.-M., & Thivolle-Cazat, J. (2014). Dynamic behaviour of tantalum hydride supported on silica or MCM-41 in the metathesis of alkanes. Catal. Sci. Technol., 4(1), 233–244. doi:10.1039/c3cy00545cPublisher
Royal Society of Chemistry (RSC)Journal
Catal. Sci. Technol.ae974a485f413a2113503eed53cd6c53
10.1039/c3cy00545c