A unified mechanism for oxidative coupling and partial oxidation of methane

Simon, Yves; Marquaire, Paul-Marie

doi:10.1016/j.fuel.2021.120683

Cited by 8 publications

(9 citation statements)

References 55 publications

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“…These species have been proposed and applied in the gas-phase reaction mechanism of methane coupling but little experimental detection has been reported because of their low concentration distribution. 22,51 CH 3 is directly observed as a reactive intermediate in OCM catalyzed by La 2 O 3 , which corresponds to the previous speculation and experimental results observed in the OCM reaction on the Li/MgO catalyst. 16,52 In addition, dimethyl ether was previously observed as the main C 2 oxygenated intermediate.…”

Section: Resultssupporting

confidence: 90%

“…In short, we detected the gas-phase intermediates of the OCM reaction including CH 3 , C 2 H 5 , and CH 2 O using the online SVUV-PIMS system. These species have been proposed and applied in the gas-phase reaction mechanism of methane coupling but little experimental detection has been reported because of their low concentration distribution. , …”

Section: Resultsmentioning

confidence: 99%

“…20 The dominance of gas-phase reactions in CO and CO 2 formation was highlighted. Simon et al 22 presented a unified kinetic model encompassing oxidative coupling and partial oxidation of methane on La 2 O 3 catalysts, elucidating both heterogeneous and homogeneous reactions in a continuous stirred tank reactor (CSTR). Gas-phase reactions were generated through EXGAS software 23 and validated against experimental data from homogeneous methane oxidation.…”

Section: Introductionmentioning

confidence: 99%

“…Surface Reactions for the Oxidative Coupling of Methane over La 2 O 3 Kinetic parameters from Karakaya et al19 e Kinetic parameters from Simon et al22 f Kinetic parameters from Schmider et al47 g Kinetic parameters from Hartmann et al48 …”

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confidence: 99%

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Elucidating the Mechanism for Oxidative Coupling of Methane Catalyzed by La₂O₃: Experimental and Microkinetic Modeling Studies

Xiong,

Guo,

Deng

et al. 2024

ACS Catal.

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Oxidative coupling of methane (OCM) has been widely proposed to be one of the most promising methods for the direct conversion of methane to C 2 products, such as ethane and ethene. Highly active free radicals play a crucial role, while accurate identifications are limited. To probe these free radicals and reveal their reactions, experiments focused on the OCM catalyzed by La 2 O 3 were designed to be carried out in a packed bed reactor at low-pressure conditions over a wide temperature range. Dozens of species, including methyl radical, ethyl radical, and formaldehyde, were observed by using synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS). A microkinetic model that coupled a detailed gas-phase and surface mechanism was developed and validated against the experimental results, especially to reveal the crucial roles of free radicals in the formation of C 2 products as well as the oxygenated intermediates. The prediction results of the kinetic model agreed well with the experimental measurements. Rate of production and sensitivity analysis were performed to reveal the complex reaction network and key reactions of the OCM. Methyl was confirmed to play a key role based on both experimental and modeling perspectives, while ethyl is crucial in the transformation of C 2 species and the formation of C 3 −C 4 species. This indicates that the selective regulation of free radicals such as methyl and ethyl in OCM is worth paying attention to. The present work provides more detailed chemistry of OCM reactions, which would be helpful to improve product selectivity of OCM.

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Section: Resultssupporting

confidence: 90%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

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Elucidating the Mechanism for Oxidative Coupling of Methane Catalyzed by La₂O₃: Experimental and Microkinetic Modeling Studies

Xiong,

Guo,

Deng

et al. 2024

ACS Catal.

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“…Similar to traditional thermal catalysis, plasma-assisted partial oxidation of methane (PPOM) is still focused on the production of syngas rather than the direct synthesis of liquid products (e.g., methanol). − The improvement of the liquid selectivity always sacrifices the CH 4 conversion, and the liquid products focus on C 1 oxygenates. Tu and Subrahmanyam developed PPOM with a total liquid selectivity of 71.5% and a CH 4 conversion of 13.0%.…”

Section: Introductionmentioning

confidence: 99%

Plasma-Assisted Cu/PCN for the Reforming of CH₄ and O₂ into C₂₊ Liquid Chemicals

Xing

et al. 2022

Ind. Eng. Chem. Res.

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Direct partial oxidation of methane to value-added chemicals and fuels under mild conditions is the "holy grail" in chemistry. Nonthermal plasma is a mild means to activate methane molecules with high efficiency, but the active species are complex, resulting in low liquid product selectivity. In this paper, Cu-decorated polymer carbon nitride (Cu/PCN-X) was prepared by a facile impregnation−calcination method. Benefiting from the strong CH 4 adsorption ability, the conversion of methane was 27.6% and the selectivity of liquid products was 63.4% when catalyzed by Cu/PCN-5 in a nonthermal plasma system. Among the liquid products, CH 3 CH 2 OH and C 3 H 6 O are the main C 2+ oxygenates via the acid sites for C−C coupling, and their selectivity in liquid products comes to 32.9%, higher than the previous report (13.4%).

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Microkinetic Modeling to Decode Catalytic Reactions and Empower Catalytic Design

Kulkarni,

Lezcano,

Velisoju

et al. 2024

ChemCatChem

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Kinetic model development is integral for designing, redesigning, monitoring, and optimizing chemical processes. Of the various approaches used within this field, microkinetic modeling is a crucial tool that focuses on surface events to analyze overall and preferential reaction pathways. This work covers noticeable features of microkinetic modeling for three critical case studies: (i) ammonia to hydrogen, (ii) oxidative coupling of methane to chemicals, and (iii) carbon dioxide hydrogenation for methanol synthesis. We analyze how microkinetic modeling enables predicting and optimizing complex reaction networks, allowing the design of efficient and tailored catalysts with enhanced activity and selectivity.

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A unified mechanism for oxidative coupling and partial oxidation of methane

Cited by 8 publications

References 55 publications

Elucidating the Mechanism for Oxidative Coupling of Methane Catalyzed by La₂O₃: Experimental and Microkinetic Modeling Studies

Elucidating the Mechanism for Oxidative Coupling of Methane Catalyzed by La₂O₃: Experimental and Microkinetic Modeling Studies

Plasma-Assisted Cu/PCN for the Reforming of CH₄ and O₂ into C₂₊ Liquid Chemicals

Microkinetic Modeling to Decode Catalytic Reactions and Empower Catalytic Design

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A unified mechanism for oxidative coupling and partial oxidation of methane

Cited by 8 publications

References 55 publications

Elucidating the Mechanism for Oxidative Coupling of Methane Catalyzed by La2O3: Experimental and Microkinetic Modeling Studies

Elucidating the Mechanism for Oxidative Coupling of Methane Catalyzed by La2O3: Experimental and Microkinetic Modeling Studies

Plasma-Assisted Cu/PCN for the Reforming of CH4 and O2 into C2+ Liquid Chemicals

Microkinetic Modeling to Decode Catalytic Reactions and Empower Catalytic Design

Contact Info

Product

Resources

About

Elucidating the Mechanism for Oxidative Coupling of Methane Catalyzed by La₂O₃: Experimental and Microkinetic Modeling Studies

Elucidating the Mechanism for Oxidative Coupling of Methane Catalyzed by La₂O₃: Experimental and Microkinetic Modeling Studies

Plasma-Assisted Cu/PCN for the Reforming of CH₄ and O₂ into C₂₊ Liquid Chemicals