Oxidative dehydrogenation of cyclohexene over cobalt-exchanged Y-zeolites

Garcia, E. Pietri De; Goldwasser, Mireya R.; Parra, Carlos Franco; Leal, O.

doi:10.1016/s0166-9834(00)80825-8

Cited by 14 publications

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“…-exchanged zeolite Y is well established efficient heterogeneous catalysts in industrial processes 1 and they have been extensively studied for the following applications: the epoxidation of styrene 2 and -pinene, 3 the disproportionation of CO, 4 the hydrodesulfurization reaction, 5 the reduction of NO, 6 the oxidation of benzyl alcohol 7,8 and methylene chloride and carbon tetrachloride, 9 the oxidative dehydrogenation of ethanol 10 and cyclohexene, 11 the ammoxidation of ethane, 12 the decomposition of N 2 O, 13 and the dehydration of ethanol. 14 To develop better Co 2+ catalysts, the positions, occupancies, and environments of Co 2+ ions in zeolites are of great interest in understanding their catalytic properties.…”

Section: +mentioning

confidence: 99%

The Effect of Co²⁺-Ion Exchange Time into Zeolite Y (FAU, Si/Al = 1.56): Their Single-Crystal Structures

Seo¹,

Kim²,

Chung³

et al. 2014

Bulletin of the Korean Chemical Society

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Section: +mentioning

confidence: 99%

The Effect of Co²⁺-Ion Exchange Time into Zeolite Y (FAU, Si/Al = 1.56): Their Single-Crystal Structures

Seo¹,

Kim²,

Chung³

et al. 2014

Bulletin of the Korean Chemical Society

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“…-exchanged zeolites have been extensively studied for their catalytic application in the hydrodesulfurization reaction [1], the epoxidation of styrene [2] and a-pinene [3], the ammoxidation of ethane [4], the disproportionation of CO [5], the reduction of NO [6], the decomposition of N 2 O [7], the oxidative dehydrogenation of ethanol [8] and cyclohexane [9], and the oxidation of benzyl alcohol [10,11] and methylene chloride and carbon tetrachloride [12]. To find better Co 2?…”

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confidence: 99%

Structural comparison of partially dehydrated partially Co2+-exchanged zeolites X (FAU, Si/Al = 1.40) and Y (FAU, Si/Al = 1.70)

Seo

Lim

2015

J Porous Mater

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The structures of partially dehydrated and partially Co 2? -exchanged zeolites X (Si/Al = 1.40) and Y (Si/ Al = 1.70) were determined by single-crystal synchrotron X-ray diffraction techniques in the cubic space group Fd 3m and were refined to the final error indices R 1 /wR 2 = 0.0773/0.2152 and 0.0683/0.2184, respectively. Their unitcell formulas are |Co 26.1 Na 21 (H 3 O) 7.1 (H 2 O) 14.2 |[Si 112 Al 80 O 384 ]-FAU (a = 24.7892(2) Å ) and |Co 29.3 Na 6.2 (H 3 O) 5.9 (H 2 O) 5.9 |[Si 121 Al 71 O 384 ]-FAU (a = 24.7346 (2) Å ), respectively. In the structure of Co 2? -X, Co 2? ions occupy sites I 0 , II 0 , II, and III 0 ; the Na ? ions are at sites I 0 and II. In the structure of Co 2? -Y, Co 2? ions occupy sites I 0 , II 0 , II, and III 0 ; the Na ? ions are at site I 0 . Because of the low pH of the Co 2? exchange solution, some H 3 O ? ions are observed in both structures. The number of Co 2? ions in zeolite was increased slightly as Si/Al ratio increased, and Na ? content and the unit cell constant of the framework were decreased.Keywords Cobalt Á Partially dehydration Á Zeolites X and Y (FAU) Á Ion exchange Á Structure zeolites X and Y (FAU) have been determined by crystallographic method [14-16, 23, 24]. Three structures of Co 2? -exchanged zeolite X (Si/Al = 1.09) were determined by X-ray diffraction techniques [23]. Co 2? exchange was performed using 0.05 M aqueous CoCl 2 Á6H 2 O in the pH range 6-7 at 296 K (crystal 1), 323 K (crystal 2), and 353 K (crystal 3). In all the cases, excess Co 2? exchange with the uptake of OHwas observed. After partial dehydration at 296 K and ca. 0.13 Pa, the numbers of Co 2? , Na ? , H 3 O ? , and OHions in the three structures Electronic supplementary material The online version of this article (

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“…-exchanged zeolites X and Y Co 2? -exchanged zeolites X and Y (FAU) have been extensively studied in catalytic applications [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. Cudejans and van Bekkum studied the influence of the solvent and the activation temperature of Co 2?…”

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confidence: 99%

“…Garcia et al studied the oxidative dehydrogenation of cyclohexene over Co 2? -exchanged (in the range 29 to 74 %) zeolite Y [20].…”

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The dependence of Co2+-exchange into zeolite FAU on its Si/Al ratio

et al. 2014

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Three single crystals of fully dehydrated, largely Co 2? -exchanged zeolites X and Y were prepared by the exchange of Na 80 -X (|Na 80 |[Si 112 Al 80 O 384 ]-FAU, Si/Al = 1.40), Na 75 -Y (|Na 75 |[Si 117 Al 75 O 384 ]-FAU, Si/Al = 1.56), and Na 71 -Y (|Na 71 |[Si 121 Al 71 O 384 ]-FAU, Si/Al = 1.70) with aqueous streams 0.05 M in Co(NO 3 ) 2 , pH = 5.1, at 294 K for 3 days. This was followed by vacuum dehydration at 673 K. Their crystal structures were determined by synchrotron X-ray diffraction techniques in the cubic space group Fd 3m at 100(1) K. In all three crystals Co 2? ions occupy the 6-ring sites I, I', and II; Na ? ions occupy sites II' and II. The number of Co 2? ions exchanging into the zeolite was about 30 per unit cell for all three crystals. The number of residual Na ? ions, however, decreased sharply as Si/Al ratio increased, and the number of H ? ions co-exchanging into the zeolite decreased nearly to zero. Some dealumination of the zeolite framework was seen in the first crystal (initial Si/Al = 1.40).

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Oxidative dehydrogenation of cyclohexene over cobalt-exchanged Y-zeolites

Cited by 14 publications

References 7 publications

The Effect of Co²⁺-Ion Exchange Time into Zeolite Y (FAU, Si/Al = 1.56): Their Single-Crystal Structures

The Effect of Co²⁺-Ion Exchange Time into Zeolite Y (FAU, Si/Al = 1.56): Their Single-Crystal Structures

Structural comparison of partially dehydrated partially Co2+-exchanged zeolites X (FAU, Si/Al = 1.40) and Y (FAU, Si/Al = 1.70)

The dependence of Co2+-exchange into zeolite FAU on its Si/Al ratio

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Oxidative dehydrogenation of cyclohexene over cobalt-exchanged Y-zeolites

Cited by 14 publications

References 7 publications

The Effect of Co2+-Ion Exchange Time into Zeolite Y (FAU, Si/Al = 1.56): Their Single-Crystal Structures

The Effect of Co2+-Ion Exchange Time into Zeolite Y (FAU, Si/Al = 1.56): Their Single-Crystal Structures

Structural comparison of partially dehydrated partially Co2+-exchanged zeolites X (FAU, Si/Al = 1.40) and Y (FAU, Si/Al = 1.70)

The dependence of Co2+-exchange into zeolite FAU on its Si/Al ratio

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The Effect of Co²⁺-Ion Exchange Time into Zeolite Y (FAU, Si/Al = 1.56): Their Single-Crystal Structures

The Effect of Co²⁺-Ion Exchange Time into Zeolite Y (FAU, Si/Al = 1.56): Their Single-Crystal Structures