The reaction mechanism of O2 oxidation of CH4 under the action of plasma cold plasma to prepare C2 hydrocarbon reaction

• Categories:Technical Support
• Author:Plasma cleaning machine-CRF plasma plasma equipment-plasma surface treatment machine manufacturer-chengfeng intelligent manufacturing
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• Time of issue:2022-02-19
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(Summary description)The reaction mechanism of O2 oxidation of CH4 under the action of plasma cold plasma to prepare C2 hydrocarbon reaction: The free radical reaction induced by plasma plasma is very similar to the heterogeneous catalytic reaction, but plasma plasma is a very effective free radical initiation method. The current consensus on the reaction mechanism of CO2 oxidation of CH4 to prepare C2 hydrocarbons in one step is that CO2 decomposes under the action of plasma to generate CO and excited and metastable reactive oxygen species. These oxygen species react in the oxidative coupling reaction of methane. is very active, according to the main products of the reaction are C2H6, C2H4, C2H2, CO and H2, the possible reaction mechanism is as follows: (1) generate oxygen species CO2 + e → CO + 0- (4-9) CO2 + e → CO + 0 + e (4-10) (2) generate methyl radical CH4 + 0- → CH3∙ + 0H- (4-11) CH4 + O → CH3∙ + OH (4-12) (3) generate C2 hydrocarbons CH3 + CH3 → C2H6 (4-13) C2H6 + e → C2H5 + H + e (4-14) C2H6 + O → C2H5 +OH (4-15) 2C2H5 → C2H4 + C2H6 (4-16) C2H5 + CH3 → C2H4 + CH4 (4-17) (4) Generate CO CHX + O → HCHO + H (4-18) HCHO + O → OH +CHO (4-19) CHO + O → OH + CO (4-20) As an effective free radical initiation method, plasma cold plasma has been successfully used in CO2 oxidation of CH4 to produce C2 hydrocarbons in one step, and has achieved better experimental results than chemical catalysis. However, the selectivity of C2 hydrocarbon products is low, and the reaction mechanism is still unclear. Therefore, it is necessary to conduct in-depth research on the one-step preparation of C2 hydrocarbons from CO2 oxidation of CH4 under the action of plasma. Using the emission spectroscopy method, many kinds of excited state species in the plasma plasma can be effectively detected in the ultraviolet-visible band, without disturbing the plasma reaction system, and in-situ analysis can be realized. Therefore, in recent years, research reports on the application of emission spectroscopy in-situ diagnostic technology to plasma systems have been increasing, but they mainly focus on the research on the deposition system of CH4-H2 diamond thin film under plasma conditions. The in situ diagnostic technique of emission spectrometry was used to analyze the reactive species of CH4 in the CO2 oxidation CH reaction system under plasma conditions with different CO2 addition amounts.