The kinetics of vapour-phase ammoxidation of 2,6-dichlorotoluene over VPO catalyst

Dropka, Natasha; Kalevaru, V. Narayana; Martin, Andreas; Linke, David; Lücke, Bernhard

doi:10.1016/j.jcat.2006.02.025

Cited by 25 publications

(23 citation statements)

References 13 publications

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“…Ammoxidations of substituted methyl aromatics and methylheteroaromatics have been performed with success in reactions catalyzed by vanadium phosphate materials (88)(89)(90)270,(284)(285)(286)(287)(288)(289)(290)(291)(292)(293). However, the ammoxidation catalysts commonly have higher phosphorus contents than the (VO) 2 P 2 O 7 (V:P ¼ 1:1) that is routinely used for oxidation, and they may have different vanadium oxidation states and are often supported.…”

Section: Ammoxidationmentioning

confidence: 99%

Vanadium Phosphate Materials as Selective Oxidation Catalysts

Dummer

Bartley

2011

Advances in Catalysis

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Section: Ammoxidationmentioning

confidence: 99%

Vanadium Phosphate Materials as Selective Oxidation Catalysts

Dummer

Bartley

2011

Advances in Catalysis

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“…Partial oxidation by air and ammonia of a methyl group present in α position of a double bond of an olefin, aromatic or heteroaromatic hydrocarbon to nitrile group, is popularly known as ammoxidation . The process is accelerated by transition metal oxides and performed in a continuous fixed bed or fluidized bed reactor.…”

Section: Introductionmentioning

confidence: 99%

“…The process is accelerated by transition metal oxides and performed in a continuous fixed bed or fluidized bed reactor. The nitriles can be used as such or can be hydrolyzed to corresponding acids or amides which are also of commercial importance . Use of nanomaterials as catalyst and transition state modeling has created revised interest in the topic.…”

Section: Introductionmentioning

confidence: 99%

“…There are limited publications on the ammoxidation of halogenated toluene. Halogenated aromatic nitriles such as chlorobenzonitriles and flurobenzonitriles find wild commercial applications as herbicides and pesticides . 2,6‐dichlorobenzonitrile (2,6‐DCLBN) can be produced by ammoxidation of 2,6‐dichlorotoluene (2,6‐DCLT).…”

Section: Introductionmentioning

confidence: 99%

“…. Usually unsupported vanadium phosphates (VPO) and V–Cr–O have been used as catalysts for the ammoxidation 2,6‐DCLT . In the last two decades, supported vanadia catalysts have received much attention for selective oxidation and ammoxidation of hydrocarbons because the use of supported catalyst has more advantages over an unsupported one.…”

Section: Introductionmentioning

confidence: 99%

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Process Development and DFT‐Assisted Mechanism of the Vapour Phase Ammoxidation of 2,6‐Dichlorotoluene to 2,6‐Dichlorobenzonitrile over the V₂O₅/γ‐Al₂O₃ Catalyst

et al. 2019

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Ammoxidation of 2,6‐dichlorotoluene (2,6‐DCLT) to 2,6‐dichlorobenzonitrile (2,6‐DCLBN) over V2O5/γ‐Al2O3 catalyst has been carried out in a fixed bed reactor. A maximum conversion of 96% of (2,6‐DCLT) and 79% yield to 2,6‐dichlorobenzonitrile have been obtained at a temperature of 425 °C, Air : 2,6‐DCLT mole ratio of 22 : 1 and NH3 : 2,6‐DCLT mole ratio of 11 : 1. A DFT theory computations have been performed with the objective of finding a mechanism of the reaction, activation energy and transition state for different reactions. Abstraction of C−H bond with an activation energy of 64.60 kcal mol−1 was found to be rate determining step. A new approach has been suggested for the reoxidation of the catalyst which supports reoxidation of every step associated with dehydration of species during the reaction. This finding is a contrary of the previous studies which assume reoxidation of the catalyst at the end of all reactions. Rapid reoxidation of the catalyst surface to release water is found to be the driving force for all reactions involving the cleavage of C−H or N−H bonds.

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Heterogeneously Catalyzed Ammoxidation: A Valuable Tool for One‐Step Synthesis of Nitriles

2010

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Ammoxidation is a partial oxidation with selective insertion of nitrogen into a methyl group (aldehyde or alcoholic groups are also able to react) that is in the α‐position to double bonds of olefinic, aromatic or heteroaromatic hydrocarbons to produce corresponding nitriles. The reaction is accelerated by heterogeneous catalysis and carried out in continuous process, in general. The heterogeneously catalyzed ammoxidation of various hydrocarbons to synthesize a wide range of industrially important nitriles has been the subject of great interest in recent times because nitriles are very useful basic chemicals (e.g. acrylonitrile) and organic intermediates (e.g. nicotinonitrile) used in the manufacture of numerous value‐added fine chemicals. The reaction proceeds with H abstraction from the methyl group, leading to an allylic or benzylic intermediate that reacts with catalyst lattice oxygen to form an oxygen‐containing intermediate through the Mars–van Krevelen mechanism. Nitrogen insertion seems to be due to adsorbed N species. Finally, nitrile formation occurs via an imine intermediate. Alkanes could be converted in a similar way, albeit with catalysts that possess a dehydrogenation function to give rise to the intermediate allylic species. Furthermore, ammoxidation is a very “green” reaction because oxygen or air is used as oxidant and water is generally the only byproduct. The ammoxidation reaction is used in the production of large‐scale chemicals, such as acrylonitrile, as well as that of intermediates, specialty chemicals, and fine chemicals in the agrochemical, health, and nutrition industries. The reaction is mostly carried out in the gas phase using supported transition metal oxides as catalysts. The most important advantage is that the ammoxidation is a simple, single‐step, eco‐friendly reaction. Nevertheless, one bottleneck is that only less‐functionalized reactants can be converted; that is, higher substituted molecules are often subject to side‐reactions. However, at present, ammoxidation is indeed a lucrative field of study, which has recently found much wider application in industry and hence will in years to come continue to offer exceptional commercial rewards for the production of industrially important nitriles.

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The kinetics of vapour-phase ammoxidation of 2,6-dichlorotoluene over VPO catalyst

Cited by 25 publications

References 13 publications

Vanadium Phosphate Materials as Selective Oxidation Catalysts

Vanadium Phosphate Materials as Selective Oxidation Catalysts

Process Development and DFT‐Assisted Mechanism of the Vapour Phase Ammoxidation of 2,6‐Dichlorotoluene to 2,6‐Dichlorobenzonitrile over the V₂O₅/γ‐Al₂O₃ Catalyst

Heterogeneously Catalyzed Ammoxidation: A Valuable Tool for One‐Step Synthesis of Nitriles

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The kinetics of vapour-phase ammoxidation of 2,6-dichlorotoluene over VPO catalyst

Cited by 25 publications

References 13 publications

Vanadium Phosphate Materials as Selective Oxidation Catalysts

Vanadium Phosphate Materials as Selective Oxidation Catalysts

Process Development and DFT‐Assisted Mechanism of the Vapour Phase Ammoxidation of 2,6‐Dichlorotoluene to 2,6‐Dichlorobenzonitrile over the V2O5/γ‐Al2O3 Catalyst

Heterogeneously Catalyzed Ammoxidation: A Valuable Tool for One‐Step Synthesis of Nitriles

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Process Development and DFT‐Assisted Mechanism of the Vapour Phase Ammoxidation of 2,6‐Dichlorotoluene to 2,6‐Dichlorobenzonitrile over the V₂O₅/γ‐Al₂O₃ Catalyst