Reaction mechanism and kinetics for the liquid‐phase catalytic oxidation of <i>meta</i>‐xylene to <i>meta</i>‐phthalic acid

Wang, Qinbo; Zhang, Yongzhao; Cheng, Youwei; Li, Xi

doi:10.1002/aic.11574

Cited by 20 publications

(25 citation statements)

References 24 publications

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“…Using some of the data at varying temperatures, with all other factors held constant, the apparent activation energy for m-xylene oxidation to MTA was estimated as *56 kJ/mol, less than the smallest reported value (63 kJ/mol) for p-xylene oxidation [19,33] and recently reported values for MX oxidation to MTA using HAc as solvent with a catalyst systems consisting of H 3 PW 12 O 40 / Co(OAc) 2 /Mn(OAc) 2 [32] or Co/Mn/Br [29,36]. The differences are not altogether unexpected, because the reaction pathways certainly differ for p-xylene, and the m-xylene oxidations cited above were all at much higher temperatures than used here, to make IPA.…”

Section: Scheme 1 Lumped Kinetics Of M-xylene Oxidationmentioning

confidence: 55%

“…2, comparing with data for a standard Co/HAc catalyst system at MX/ HAc = 1.8-4.1 (molar), Co/MX = 3.5-3.9 mmol/mol. Note that this is a much higher MX/HAc ratio than used in experiments where IPA is the desired product [12,29,32,36]. Table 1 summarizes the reaction conditions and the key results for m-xylene oxidation using the modified homogeneous catalyst systems.…”

Section: Resultsmentioning

confidence: 99%

“…Based on a similar oxidation mechanism involving electron transfer followed by hydrogen abstraction [3,4,15,16,28,29], the catalytic oxidation of mixed xylenes or PX can provide insight into the oxidation of MX. Highly acidic solutions effective for PX oxidation [1,4,21,23], e.g., HAc solutions and bromide salts, can be used in MX oxidation [6].…”

Section: Introductionmentioning

confidence: 99%

“…Almost all of these are on oxidation to IPA [8,12,13,27,[29][30][31][32]. These reaction systems are operated at up to 480 K, employing a corrosive solvent (HAc) and/or Brfor high catalytic efficiency [12,[30][31][32].…”

Section: Introductionmentioning

confidence: 99%

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Waste-Reducing Catalytic Oxidation of m-Xylene to m-Toluic Acid

2016

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Catalytic performances of soluble Co, Co/Mn, Co/Mn/Br, and Co/Mn/Ce catalysts for m-xylene (MX) oxidation without acetic acid (HAc) solvent were studied, comparing with Co/HAc catalysts. In m-toluic acid (MTA) production, a Ce-salt promoter could effectively substitute for bromide salts and the recycle alcohol/aldehyde liquid mixture acts as a more efficient promotor than either peroxides or MTA itself. The Co/Mn/Ce system, free of acetic acid and Br -, was a superior catalyst in terms of activity and selectivity to MTA. Just as for p-xylene oxidation using Co/Mn/Br catalysts, both the MX reaction rate and the MTA selectivity increased with temperature when using Co/Mn/Ce catalysts. Unlike p-xylene oxidation however, MX oxidation resulted in more coupling products. For MX oxidation catalyzed by a supported Co-imide complex in supercritical CO 2 , the activity was lower by more than an order of magnitude, but the MTA selectivity was greater.Graphical Abstract The selectivity behavior of the catalyst systems indicate that the Co/Mn/Ce system, free of acetic acid solvent and corrosive Br -, was a superior catalyst, both in terms of overall activity and selectivity for MTA.

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Section: Scheme 1 Lumped Kinetics Of M-xylene Oxidationmentioning

confidence: 55%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Waste-Reducing Catalytic Oxidation of m-Xylene to m-Toluic Acid

2016

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“…Elucidation of the reaction mechanism helps in selecting more efficient catalyst, optimizing reaction conditions, and designing a more profitable reactor . This process also evokes ideas for further research and development.…”

Section: Coupling Reaction Mechanism and Kinetic Modelmentioning

confidence: 99%

Reaction mechanism and kinetics for the catalytic coupling reaction from carbon monoxide to diethyl oxalate

Zhu

Luo

2012

Asia-Pacific J Chem Eng

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A comprehensive reaction mechanism was proposed for the gas‐phase catalytic coupling reaction from carbon monoxide to diethyl oxalate over supported metal catalyst Pd‐Zr/Al2O3 at atmospheric pressure. Based on the reaction mechanism, two assumptions of rate‐controlling step, namely the adsorption of carbon monoxide and the surface reaction between adsorbed species over the catalyst were investigated. Two simplified hyperbola‐like kinetic models corresponding to the respective rate‐controlling steps were derived accordingly, and the kinetic parameters were determined by fitting the experimental data. The statistic test and the comparison between experimental and simulated data showed that the kinetic model with rate controlled by surface reaction outperformed the one controlled by adsorption. Finally, the optimization of principal operating conditions was applied to the appropriate kinetic model. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.

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Kinetic studies on the liquid‐phase catalytic oxidation of 4‐methyl guaiacol to vanillin

Liu

Mao

et al. 2017

Can J Chem Eng

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Kinetic studies on the catalytic oxidation of 4‐methyl guaiacol using an ether intermediate towards vanillin in an agitator bubbling reactor were presented. The reaction was catalyzed by N,N′‐ethylenebis(acetylacetoniminato)‐cobalt(II) hexafluorophosphoric pyridinium (Co‐[Salen‐Py][PF6]2) under strong alkaline conditions with molecular oxygen as the terminal oxidant. The reaction scheme was demonstrated by a detailed analysis of the products distribution and control experiments. The intrinsic kinetics were explored based on our proposed p‐benzoquinone methide mechanism, which revealed that the oxidation rate was determined by the oxidation of phenoxyl anion to phenoxyl radical catalyzed by LCo3+(O2·) (L = [Salen‐Py][PF6]2). The kinetic experiments were performed under a mass transfer‐reaction condition due to the inevitable mass transfer resistance involved. Pseudo‐first order fast reactions were observed for both steps of the consecutive reactions based on the calculated physical and mass transfer parameters. The intrinsic kinetic equations for the first and second steps can be written as RA=5.98×105exp(−31950RT)CCcat.CO2A and RF=1.02×106exp(−29770RT)CCcat.CO2E, respectively, which are well in accordance with the mechanism. These conclusions are expected to give a clue for the mechanistic study, kinetic investigation, reaction optimization, and catalyst design for the oxidation of various p‐cresols.

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Reaction mechanism and kinetics for the liquid‐phase catalytic oxidation of meta‐xylene to meta‐phthalic acid

Cited by 20 publications

References 24 publications

Waste-Reducing Catalytic Oxidation of m-Xylene to m-Toluic Acid

Waste-Reducing Catalytic Oxidation of m-Xylene to m-Toluic Acid

Reaction mechanism and kinetics for the catalytic coupling reaction from carbon monoxide to diethyl oxalate

Kinetic studies on the liquid‐phase catalytic oxidation of 4‐methyl guaiacol to vanillin

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