介质阻挡放电引发氮氧化物等离子体化学反应  

Plasma-induced Conversion of Nitro gen Oxides in a Dielectric Barrier Di scharge Reactor

作　　者：孙琪[1] 朱爱民[1] 牛金海[1] 徐勇[1] 宋志民[1] 

机构地区：[1]大连理工大学化工学院等离子体物理化学实验室,大连116024

出　　处：《物理化学学报》2005年第2期192-196,共5页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(20077005);国家863计划青年资助项目(2002AA649140);辽宁省科学技术基金(20022112)资助~~

摘　　要：在523K介质阻挡放电条件下,研究了不同气体组分体系中NO的转化.实验表明,在无氧体系(NO/N2)中,转化的NO主要分解为N2和O2.在富氧(NO/O2/N2)条件下,由于NO和NO2的生成,NO的转化率最低.体系中加入C2H4(NO/C2H4/N2)时,NO转化率与NO/N2体系几乎一样,与NO相比,生成的O更易与C2H4作用,几乎没有NO2的生成.当C2H4和O2共存时(NO/O2/C2H4/N2),NO主要被氧化为NO2.当能量密度为125J·L-1时,与其它体系相比,NO/O2/C2H4/N2体系中NO转化率和NO2生成量最大,转化每个NO分子能耗最小(61eV).体系中C2H4主要被氧化为CO.四个体系中N2O的生成量都较少.讨论了介质阻挡放电条件下上述四个体系可能的反应机制.In order to understand the mechanism of NO. removal in non-thermal plasma, the conversion of NO with different reacting gas mixtures under atmospheric pressure has been studied using dielectric barrier discharge plasma at 523 K. Experiments demonstrate that in the NO/N-2 system, NO decomposition to N-2 and O-2 is in the majority. In the NO/O-2/N-2 system, NO conversion is the lowest for the formation of NO2 and NO. In the NO/C2H4/N-2 system, NO is reduced to N-2 at the same NO conversion as that in the NO/N-2 system. Because the O atoms from NO decomposition are consumed more effectively by reaction of O andC(2)H(4) than reaction of O and NO, NO2 formation is not observed. Dielectric barrier discharge is a very effective means for oxidizing NO to NO2 in the NO/O-2/C2H4/N-2 system. At the energy density of 125 J (.) L-1, NO conversion and concentration of NO2 formed in the NO/O-2/C2H4/N-2 system are the highest, the energy consumption is the lowest, 61 eV per converted NO molecule. C2H4 is mainly oxidized to CO in the dielectric barrier discharge plasma. A small amount of N2O is formed in the four systems. The in-situ optical emission spectra (200 similar to 900 nm) have also been investigated under atmospheric pressure at 523 K. The observations of N-2 second positive band, NO gamma-band and NO beta-band with different gas mixtures imply that some excited-state active species from plasma-induced processes can effectively convert NO. Finally, mechanisms for the NO conversion in the four systems were proposed on the basis of experiment and relative literature.

关 键 词：介质阻挡放电 氮氧化物 乙烯 等离子体化学 发射光谱 

分 类 号：X701.3[环境科学与工程—环境工程]