Liquid phase transformation of α-pinene over Beta zeolites containing aluminium or boron, titanium and vanadium as lattice ions

Gündüz, Gönül; Dimitrova, R.; Dimitrov, L.

doi:10.1016/j.apcata.2004.11.046

Cited by 34 publications

(15 citation statements)

References 26 publications

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“…Under the reaction conditions examined in that work (50 g of α pinene, 1 g of catalyst, 145-150°C), Lewis sites do not participate in the reaction. This is at variance with the inferences made by other authors [12,22].…”

Section: Introductioncontrasting

confidence: 78%

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New α-pinene isomerization catalysts

et al. 2011

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Current views of the mechanism of the catalytic isomerization of α pinene were discussed. Cata lytic systems, modifiers, process conditions, and the effect of process conditions on catalytic activity and on the target product (camphene, dipentene) selectivities of the process were considered. α Pinene isomeriza tion was investigated over a Belarussian natural aluminosilicate (Al-Si RB), its derivatives modified with HCl and H 3 PO 4 , modified diatomite (Al/Dia), and bentonite (ZSM 5/Ben). The commercial aluminosilicate catalyst AS 36 was used as a reference sample. Al-Si RB was treated with 10% HCl (50-250 ml/g) or 10% H 3 PO 4 (50-100 ml/g) at 50°C for 3 h. α Pinene was isomerized in a round bottom flask with a backflow condenser under flowing nitrogen. The rotational speed of the stirrer was 10 rps. The highest catalytic activity and the highest camphene selectivity were observed for Al-Si RB treated with 50 ml/g of HCl. With activated Al-Si RB and As 36, 85% α pinene conversion at 130°C and a catalyst concentration of 0.5 wt % was attained in 5.5 and 7 h, respectively. The camphene selectivity for Al-Si RB treated with 50 ml/g of HCl was 61%, being ~20 and ~10% higher than in the case of AS 36 and Al/Dia, respectively. Al-Si RB retained its catalytic activity for 70 h and could be fully regenerated with acetone.

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Section: Introductioncontrasting

confidence: 78%

“…Many studies on α pinene isomerization catalysts have been devoted to natural aluminosilicates [5,8,11,12,16,31,[45][46][47][48][49][50][51], zeolites [8,12,22,24,31,51], and zirconium sulfate [10,[52][53][54].…”

Section: Activation Of α Pinene Isomerization Catalysts With Acidsmentioning

confidence: 99%

New α-pinene isomerization catalysts

et al. 2011

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“…Stimulated by the success of TS‐14 in a variety of liquid‐phase selective oxidations, a number of researches were performed on the synthesis and catalytic application of Ti(IV)‐containing catalysts. Using organic orthotitanate as Ti(IV) precursors and surfactants or small organic compounds as structure‐directing agents, Ti‐containing microporous zeolites,5, 6 mesoporous materials,6–8 or even titanium silicate analogous organic–inorganic hybrids9 were prepared.…”

Section: Introductionmentioning

confidence: 99%

On the nature of Ti(IV)‐pillared layered metal hydroxides prepared from green, water‐soluble Ti‐peroxide

Shi

Shu

et al. 2009

AIChE Journal

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Ti-peroxide pillared layered double hydroxides (LDHs) have been prepared for the first time using water-soluble Ti-peroxide as an intercalating precursor. It is novel and alluring that the whole preparation procedure does not involve any usage of organic or chlorine-containing hazards. Intercalated into the LDH interlayer region, Ti-peroxide is prevented partially from condensation in the solvent evaporation. The interlayer TiAO 2 unit exists in triangular (g 2 ) structure with C 2m symmetry in most cases, giving an interlayer gallery of 0.50-0.60 nm. But in the case of pH 4.0, monodentate (g 1 ) structure is also observed, giving an interlayer gallery of 0.70 nm. All the Ti-peroxide pillared LDHs prepared in this work show catalytic activity in the selective oxidation of thioether. The Ti-peroxide introduced into the interlayer regions of Mg/Al LDH with a particle size of around 50-120 nm exhibits better recyclability than Ti-peroxide gel, either in bulk or adsorbed on the exterior surface of LDH particles. V

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“…Among them, cationic polymerization is the most important. Lewis acids such as AlCl 3 , BF 3 , TiCl 4 [8][9][10][11] are the most effective catalysts of cationic polymerization and therefore commonly used in the commercial processes. But these halides may cause severe problems of environmental hazards, equipment corrosion and poisoning of hydrogenation catalysts in later hydrogenation processes.…”

mentioning

confidence: 99%

Cationic polymerization of α-pinene using Keggin silicotungstic acid as a homogeneous catalyst

Liu

Zhang

Zeng

et al. 2011

Reac Kinet Mech Cat

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Cationic polymerization of a-pinene with silicotungstic acid (SiW 12 ) as a catalyst was investigated. The structure of polymers and the catalysts were characterized by FT-IR, 1 H-NMR and GPC. The experiments show that SiW 12 is more active than both phosphotungstic acid and phosphomolybdic acid. The protons dissociating from the catalysts are the reactive species. SiW 12 is found to be both the polymerization initiator and the counter-anion of the growing cationic center. The polymerization conditions are optimized by the single factor method as follows: monomer concentration is 50% (v/v), the dosage of catalysts is 7 wt% referred to a-pinene, reaction temperature is 50°C, reaction time is 1 h. Under these conditions, the overall conversion of a-pinene is up to 90.87%, the polymer yield is 62.46% and its average number molecular weight is about 600. GC-MS analysis shows that there are six isomers of a-pinene after the reaction, but their content is very low. Most of a-pinene are changed to poly(a-pinene).

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Liquid phase transformation of α-pinene over Beta zeolites containing aluminium or boron, titanium and vanadium as lattice ions

Cited by 34 publications

References 26 publications

New α-pinene isomerization catalysts

New α-pinene isomerization catalysts

On the nature of Ti(IV)‐pillared layered metal hydroxides prepared from green, water‐soluble Ti‐peroxide

Cationic polymerization of α-pinene using Keggin silicotungstic acid as a homogeneous catalyst

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