Tailored Alkene Oligomerization with H-ZSM-57 Zeolite

Abstract

The unique lobate‐pore structure of acidic ZSM‐57 zeolite favors the crosswise arrangement of light alkenes and thus their selective dimerization into C6–C12 oligomers (see picture). Allylic hydrogen abstraction and deactivation generally observed with other acidic zeolites is largely suppressed in ZSM‐57.

Multipore Zeolites: Synthesis and Catalytic Applications

“…ZSM‐57 is synthesized using the linear dicationic N , N , N , N ′, N ′, N ′‐hexaethylpentanediammonium as the OSDA (Figure 3). 32 Interestingly, molecular‐modeling studies indicate that these OSDA molecules are placed along the 10‐ring channels with their positive charges in the channel intersection/lobes, consequently directing to a preferential positioning of the acid sites in these intersection/lobes 33. This process is very interesting because the unique lobate‐pore structure of ZSM‐57 and the acid site distribution favor the activity and selectivity for alkene oligomerizations that require the crosswise arrangement of alkenes 33.…”

“…32 Interestingly, molecular‐modeling studies indicate that these OSDA molecules are placed along the 10‐ring channels with their positive charges in the channel intersection/lobes, consequently directing to a preferential positioning of the acid sites in these intersection/lobes 33. This process is very interesting because the unique lobate‐pore structure of ZSM‐57 and the acid site distribution favor the activity and selectivity for alkene oligomerizations that require the crosswise arrangement of alkenes 33. ZSM‐57 gives higher conversions than other zeolites for the oligomerization of 1‐butene, with better yields of the desired branched C 8 products 33…”

“…This process is very interesting because the unique lobate‐pore structure of ZSM‐57 and the acid site distribution favor the activity and selectivity for alkene oligomerizations that require the crosswise arrangement of alkenes 33. ZSM‐57 gives higher conversions than other zeolites for the oligomerization of 1‐butene, with better yields of the desired branched C 8 products 33…”

Improved THETA-1 for Light Olefins Oligomerization to Diesel: Influence of Textural and Acidic Properties

“…For the production of diesel, where branching of the hydrocarbons has to be limited, SSPA is, however, not suitable, and zeolite based catalysts have been proposed for gas phase [1,[9][10][11][12] and liquid phase operation [13][14][15][16]. When oligomerization of light olefins is carried out in the presence of heterogeneous acid catalysts, the reaction mechanism involves carbenium ions and the branching degree of product oligomers -isoolefins-is known to be proportional to the size of the catalysts pore.…”

Multiporige Zeolithe: Synthese und Anwendungen bei der Katalyse

“…ZSM‐57 wird unter Verwendung von N , N , N , N ′, N ′, N ′‐Hexaethylpentandiammonium als lineares dikationisches OSDA synthetisiert (Abbildung 3). 32 Molecular‐Modeling‐Rechnungen weisen darauf hin, dass diese OSDA‐Moleküle entlang der 10‐Ring‐Kanäle mit ihren positiven Ladungen in den Kreuzungen/Keulen der Kanäle angeordnet sind, folglich also die Positionierung der sauren Zentren bevorzugt auf diese Kreuzungen/Keulen lenken 33. Dies ist sehr interessant, da die besondere Keulen‐Poren‐Struktur von ZSM‐57 und die günstige Verteilung von sauren Zentren die Aktivität und Selektivität für Alken‐Oligomerisierungen durch kreuzweise Anordnung von Alkenen begünstigen 33.…”