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Liquid-phase ␣-pinene isomerisation at l00• C in a batch reactor is studied over Beta zeolites synthesised by different methods. It is confirmed that ␣-pinene forms a carbenium ion in an acidic environment, which rearranges without capture by nucleophiles, to form mainly hydrocarbons as camphene, terpinenes, terpinolenes and heavy products. The microporous Beta samples show low activity despite the high acidity most probably because of the hindered intermediate formation. The nature of the enhanced activity of Beta mesopores samples is suggested to be a result from the high accessibility of the acidic sites.

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“…3 shows terpinenes and HRTP as a function of ␣-pinene conversion. Similar results have been reported in literature [35].…”

Section: Resultssupporting

confidence: 93%

Isomerisation of α-pinene over Beta zeolites synthesised by different methods

Gündüz

Dimitrova

Yılmaz

et al. 2005

Journal of Molecular Catalysis A: Chemical

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“…These samples were analyzed using an HP 6890 GC/FID. A more detailed description of the qualitative and quantitative analyses can be found elsewhere [13][14][15][16].…”

Section: Catalytic Experimentsmentioning

confidence: 99%

“…The numerous efforts to overcome this drawback are reported in the literature [1,2]. Especially, zeolites have been widely studied as a potential alkylation catalyst with intensive characterization to identify their desirable properties for the reaction [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. However, the correlation between the physicochemical properties of zeolites and catalytic performance has reminded unclear.…”

Section: Introductionmentioning

confidence: 99%

Zeolites-catalyzed Alkylation of Isobutane with 2-butene: Influence of Acidic Properties

Yoo

Smirniotis

2005

Catal Lett

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The influence of acidity properties of zeolites on the alkylation of isobutane with 2-butene was studied using ultrastable Y (USY) zeolites. Most zeolites possessed almost comparable hydrogen transfer activity except for USY-30, which has the lowest acid site density. On the other hand, the strength of acid sites increased with degrees of dealumination. During the alkylation, a maximum in catalytic activity for certain Si/Al ratios were observed. This behavior is believed to be a result of a balanced level of acidic properties between the concentration and strength of Brønsted acid sites. It can prohibit the formation of heavy carbonaceous materials that deactivate the zeolites.

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“…Among these are 13 C NMR spectroscopy [12,13], IR spectroscopy [14], UV-vis spectroscopy [15], temperature-programmed oxidation [16], matrix assisted laser desorption ionization-time of flight spectroscopy (MAL DI-TOF) [14] and dissolution of the zeolite in HF with subsequent extraction and analysis of the organic phase [17,18]. However, except for the investigations of Pater et al [19] and Feller et al [14], all these prior studies were undertaken with catalysts that had already passed the alkylation stage.…”

Section: Introductionmentioning

confidence: 99%