甲烷电离特性的等离子体发射光谱法研究  

Study on Optical Emission Spectroscopy of Pulse Corona Methane Plasma

作　　者：李金平[1,2] 代斌[2] 范婷[1] 

机构地区：[1]石河子大学师范学院物理系,新疆石河子832003 [2]石河子大学化学化工学院,新疆石河子832003

出　　处：《光谱学与光谱分析》2009年第7期1979-1982,共4页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(20363003);教育部新世纪优秀人才支持计划(NCET-04-0988)联合资助

摘　　要：应用等离子体发射光谱法，用CCD（charge coupled device）光栅光谱仪记录并标识了脉冲电晕甲烷等离子体370～1 100 nm的发射光谱，确定了常温常压下高纯甲烷（99.99%）经100 kV, 100 Hz脉冲高压电离后的产物为H，C＋,CH，C，C2,C3, C4,C5和烃等。通过分析实验检测到的甲烷等离子体发射光谱，给出了甲烷经脉冲高压电离形成电晕等离子体的机理和自由基CHn（n=3，2，1）、碳、烃等产物的电离途径。结果显示甲烷分子经高能电子非弹性碰撞后脱氢程度很高，大量氢原子及其离子和甲烷自由基在进一步被高能电子作用下合成了烯烃、炔烃、烷烃和高聚碳化物。实验所获得的脉冲甲烷等离子体发射光谱及其机理分析可为甲烷及其转化研究提供相关依据。From experiments of methane pulse corona plasma and plasma emission spectrometry, the emission spectra of methane ranging from 370 to 1 100 nm were recorded and marked with CCD （Charge Coupled Device） grating spectrometry. The ionization products of H, C^＋, CH, C, C2, C3, C4, C5 and hydrocarbon were confirmed through high purity methane （purity 99. 99%） ionized by pulse high voltage of 100 kV and 100 Hz under normal temperature and normal pressure. Through analyzing the experimental emission spectrum of methane plasma, the ionization mechanism, i.e. methane gas was ionized into corona plasma by pulse high voltage, was analyzed and the ionization of free radical CH, （n=3, 2, l）, carbon and hydrocarbons was given as well. Research results show that the dehydrogenation achieved a high level when methane molecules collide inelastically with high energy electrons, and the hydrogen atoms, hydrogen ions and methane free radicals were synthesized into alkenes, alkynes, alkanes and high polymer of carbon with further inelastic collision of high energy electrons. This experimental spectrum and mechanism analysis can be applied to the research on methane conversion.

关 键 词：甲烷 脉冲电晕等离子体 等离子体发射光谱 自由基 

分 类 号：O433.4[机械工程—光学工程] O531[理学—光学]