IR studies of Re2O7 metathesis catalysts supported on alumina and phosphated alumina

Sibeijn, M.; Spronk, Rachel; Veen, J.A.R. van; Mol, J.C.

doi:10.1007/bf00764117

Cited by 56 publications

(37 citation statements)

References 6 publications

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“…A positive correlation between the catalytic activity and the surface acidity (mainly the Br0nsted acidity) has been observed [51,52]. The activity of ReZ07/Ah03 catalysts can be explained on the basis of the activity of the surface Re04 groups that have reacted with Lewis acid sites and with the different aluminium-bonded OR groups during the preparation of the catalyst [46]. The most active sites arise from the reaction between Re04· ions and the most acidic OR groups on the alumina surface to form AI-bonded Re04 species.…”

Section: Rhenium Catalystsmentioning

confidence: 95%

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Applications of Olefin Metathesis in the Oleochemistry

Mol

2002

Ring Opening Metathesis Polymerisation and Related Chemistry

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Section: Rhenium Catalystsmentioning

confidence: 95%

“…VZ0 5, Mo03 or W03) [43]; (ii) the use of a modified support, e.g. SiOr Alz03 [44], AI20 r B20 3 [45], phosphated alumina [46] or borated silica-alumina [47]; (iii) the use of other promoters, such as Et4Sn, BU4Sn or E4Pb [17]. As tin and lead compounds are quite toxic, other promoters are being sought for.…”

Section: Rhenium Catalystsmentioning

confidence: 99%

Applications of Olefin Metathesis in the Oleochemistry

Mol

2002

Ring Opening Metathesis Polymerisation and Related Chemistry

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“…All spectra are presented with normalized intensities. 11 B MAS NMR analyses were performed at room temperature on a Varian-INOVA 500 spectrometer operating at a frequency of 160.38 MHz, using a DOTY Super Sonic 5 mm probe and a spinning rate of 6.1 kHz. All spectra were obtained using a 30 • pulse width of 1 s. Delay between each scan: 1 s. Chemical shifts were reported on the basis of assigning the trigonally coordinated 11 B peak in boric acid (H 3 BO 3 ) to δ = 20 ppm.…”

Section: In Situ Ft-ir Studies Of Adsorbed Pyridinementioning

confidence: 99%

“…The relationship between catalytic activity and Brönsted acidity has been explained as follows: the active sites would result from a reaction between ReO 4 − ions and the most acidic hydroxyl groups of the surface. On alumina, this reaction is favored only after the basic and neutral OH − groups have reacted to some extent [11], which explains why high rhenium loadings (ca. 18 wt.% Re 2 O 7 ) are needed.…”

Section: Introductionmentioning

confidence: 98%

Characterization and catalytic performance of rhenium oxide-based catalysts supported on borated silica-alumina

Rodella

Buffon

2004

Applied Catalysis A: General

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“…A po si ti ve cor re la ti on bet we en the cataly tic ac ti vity and the sur fa ce aci dity (ma inly the Bröns ted aci dity) of such systems has been ob ser ved 44,45 . The ac ti vity of Re 2 O 7 /Al 2 O 3 ca talysts can be ex pla i ned on the ba sis of the ac ti vity of the sur fa ce ReO 4 groups which have re ac ted with Le wis acid si tes and with the dif fe rent alu mi nium-bonded OH groups du ring the pre pa ra ti on of the catalyst 41 . The most ac ti ve si tes ari se from the re ac ti on bet ween ReO 4 -ions and the most aci dic OH groups on the alu mi na sur fa ce to form Al-bonded ReO 4 spe ci es.…”

Section: Struc Tu Re X Ca Taly Tic Ac Ti Vitymentioning

confidence: 99%

Metathesis in Oleochemistry

Mol

Buffon

1998

J. Braz. Chem. Soc.

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Cam pi nas -SP, Bra zilRe ce i ved: June 6, 1997 Me tá te se é uma re a ção atra en te para a con ver são de óle os e gor du ras em pro du tos quí m i cos úte is. Assim, a me tá te se de és te res de áci dos gra xos in sa tu ra dos (cons ti tu in tes bá si cos de óle os e gor du ras) é uma rota con ve ni en te para a sín te se de diés te res in sa tu ra dos, que po de m ser usados como in ter me diá ri os na pro du ção de po lí me ros e na quí mi ca fina. A me tá te se cru z a da com ole fi nas sim ples per mi te al te rar o com pri men to da ca de ia car bo na da de áci dos gra xo s e de seus de ri va dos; a me tá te se cru za da com ete no (ete nó li se) for ne ce com pos tos con ten do li ga ções duplas ter mi na is, que pos su em uma ex ten sa gama de apli ca ções. A ete nó li se de óle os gra x os (trigli ce rí de os) per mi te a trans for ma ção de tri gli ce rí de os de áci dos gra xos de lon gas ca de i as car bo na das em óle os gra xos de me nor mas sa mo le cu lar. Di ver sos sis te mas ca ta lí ti co s -ho mogê ne os ou he te ro gê ne os -, al ta men te se le ti vos, se mos tra ram ca pa zes de efe tu ar a me tá te se de és te res in sa tu ra dos. Ca ta li sa do res he te ro gê ne os à base de rê nio ou de mo lib dê ni o têm atra í do mu i ta aten ção. Con si de ran do os pro ce di men tos de ati va ção e de re ge ne ra ção do ca ta li sa dor, os sis te mas ca ta lí ti cos à base de rê nio são pre fe ri dos.Me tat he sis is an at trac ti ve re ac ti on for the con ver si on of ole o che mi cal fe eds tock s into useful che mi cal pro ducts. Thus, me tat he sis of un sa tu ra ted fatty acid es ters (the ole o che mi cal raw ma te ri als) pro vi des a con ve ni ent rou te to un sa tu ra ted di es ters which can be used as in ter me di ates for the pro duc ti on of poly mers and spe ci alty che mi cals. Cross-metathesis with ole fins is a me ans to chan ge the cha in length of fatty acids and de ri va ti ves; cross-metathesis with et he ne (et he noly sis ) gi ves com pounds with ter mi nal dou ble bonds, ha ving a bro ad ran ge of ap pli ca tions. Ethe noly sis of fatty oils or trigl yce ri des al lows the trans for ma ti on of long-chain f atty acid trigl yce ri des into fatty oils of lo wer mo le cu lar we ight. Se ve ral highly se lec ti ve ca t alyst systems -ho mo ge ne ous as well as he te ro ge ne ous -have pro ven to be suc cess ful for the m e tathe sis of un sa tu ra ted es ters. Espe ci ally mo di fi ed he te ro ge ne ous rhe ni um-and moly bdenum-based ca talysts have at trac ted much at ten ti on. Con si de ring ca talyst ac ti va ti on an d re ge ne ra ti on pro ce du res, rhe ni um-based ca talysts are to be pre fer red. Key words: me tat he sis, ca talysts, ole o che mi cals, es ters Intro duc ti on Fats and oilsIn the next cen tury the ava i la bi lity of fos sil or ga nic feeds tocks -both as energy sour ces and for the pro duc ti on of or ga nic che mi cal raw ma te ri als -will gra du ally de cre a se. Hen ce it is im por tant to look for al ter na ti ves. The se can be found in ...

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IR studies of Re2O7 metathesis catalysts supported on alumina and phosphated alumina

Cited by 56 publications

References 6 publications

Applications of Olefin Metathesis in the Oleochemistry

Applications of Olefin Metathesis in the Oleochemistry

Characterization and catalytic performance of rhenium oxide-based catalysts supported on borated silica-alumina

Metathesis in Oleochemistry

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