Skeletal isomerisation of oleic acid over ferrierite in the presence and absence of triphenylphosphine: Pore mouth catalysis and related deactivation mechanisms

[Display omitted] •Ferrierite catalyses the alkyl branching of oleic acid with high activity and selectivity.•Reuse experiments indicate severe deactivation, despite framework conservation.•Micropore blockage occurs early on in the reaction, suggesting the existence of pore mouth catalysis.•The acid...

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Vydáno v:	Journal of catalysis Ročník 316; s. 24 - 35
Hlavní autoři:	Wiedemann, Sophie C.C., Stewart, Joseph A., Soulimani, Fouad, van Bergen-Brenkman, Tanja, Langelaar, Stephan, Wels, Bas, de Peinder, Peter, Bruijnincx, Pieter C.A., Weckhuysen, Bert M.
Médium:	Journal Article
Jazyk:	angličtina
Vydáno:	Amsterdam Elsevier Inc 01.07.2014 Elsevier Elsevier BV
Témata:	benzene Catalysis catalysts catalytic activity Chemical engineering Chemistry Coke Colloidal state and disperse state Deactivation Exact sciences and technology Fatty acid isomerisation Ferrierite Fourier transform infrared spectroscopy General and physical chemistry hydrogen Ion-exchange mass spectrometry nuclear magnetic resonance spectroscopy Oleic acid Oleochemistry Petrochemicals Porous materials skeletal isomerization spectral analysis Surface physical chemistry Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry ultraviolet-visible spectroscopy Zeolites: preparations and properties BUFA Ferrierite OA MO Deactivation TPP Oleic acid Fatty acid isomerisation Oleochemistry Catalytic reaction Isomerization Zeolite Fatty acids Porous material Mechanism Heterogeneous catalysis Pore
ISSN:	0021-9517, 1090-2694
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Popis
Shrnutí:	[Display omitted] •Ferrierite catalyses the alkyl branching of oleic acid with high activity and selectivity.•Reuse experiments indicate severe deactivation, despite framework conservation.•Micropore blockage occurs early on in the reaction, suggesting the existence of pore mouth catalysis.•The acid sites are poisoned by the formation of (poly)enylic carbocations.•Long chain alkyl benzenes are found to be the major coke constituents. The formation and nature of coke (precursor) species has been studied during the skeletal isomerisation of oleic acid catalysed by protonated ferrierite, in the presence and absence of a triphenylphosphine promoter. UV–Vis and FT-IR spectroscopic analyses of the spent catalyst materials, complemented by NMR and mass spectrometry of the coke deposits extracted after HF dissolution, provide new insights into the deactivation mechanisms. Initial high catalyst activity and selectivity are quickly lost, despite conservation of the framework integrity, as a result of severe deactivation. Pore blockage is detected very early in the reaction, and only the pore mouth is actively employed. Additionally, polyenylic carbocations formed by hydrogen transfer reactions poison the active sites; they are considered to be the precursors to traces of condensed aromatics detected in the spent catalyst. Dodecyl benzene is the major “coke” constituent, and its precursor probably also competes for the active sites.
Bibliografie:	ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 14 content type line 23
ISSN:	0021-9517 1090-2694
DOI:	10.1016/j.jcat.2014.04.018