介质阻挡放电等离子体与吸附在CuZSM-5上的NO或NO/O2的相互作用  

Interactions of Dielectric Barrier Discharge Plasmas with NO or NO/O_2 Adsorbed on CuZSM-5

作　　者：孙琪[1,2] 任亮[3] 牛金海[1] 宋志民[1] 

机构地区：[1]大连理工大学等离子体物理化学实验室 [2]辽宁师范大学化学化工学院,辽宁大连116029 [3]辽宁师范大学化学化工学院

出　　处：《物理化学学报》2008年第7期1214-1218,共5页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(20077005);辽宁省自然科学基金(20072154)资助项目

摘　　要：采用吸附和程序升温脱附(TPD)技术研究了介质阻挡放电等离子体对CuZSM-5催化剂上吸附的氮氧化物作用.实验表明,介质阻挡放电等离子体使催化剂表面吸附的NO及Cu活性位上吸附的NOx物种脱附,并引发表面化学反应生成新的氮氧化物.对于NO/N2体系,介质阻挡放电等离子体与吸附在CuZSM-5上NO作用,主要生成N2O和O2.在富氧体系NO/O2/N2,则生成较大量的N2O、NO2和NO.等离子体预处理活性下降的CuZSM-5,可明显提高其催化分解NO活性.对比有或无介质阻挡放电等离子体预处理NO或NO/O2饱和吸附的CuZSM-5上的NO-TPD结果表明,等离子体提高催化剂活性的原因与其使催化剂Cu活性位上吸附的NOx物种脱附有关.In order to understand the synergistic effects between dielectric barrier discharge （DBD） plasmas and catalysts, the interactions between DBD and NO or NO/O2 saturated CuZSM-5 have been studied by adsorption and temperature programmed desorption （TPD） techniques. The results demonstrated that NO adsorbed on the CuZSM-5 surface and NOx species adsorbed on Cu active sites could be partly desorbed by DBD plasmas. Nitrogen oxides could be formed by plasma-induced surface reactions. A small amount of N2O and O2 could be formed in the NOfN2 system, and a significant amount of NOx （N2O, NO2, and NO） was generated in the NO/O2/N2 system by interactions between DBD plasmas and NO or NO/O2 adsorbed CuZSM-5. NOx removal over CuZSM-5 was tested by means of CuZSM-5 with or without plasma-pretreatment. After CuZSM-5, which had showed lower activity, was pretreated by N2 flow or DBD plasmas, NOx conversions in NOfN2 were 30.3% and 46.7%, respectively. The corresponding NOx conversion over fresh CuZSM-5 catalyst was 39.2% in NO/N2. A comparison of TPD profiles of NO and 02 over CuZSM-5 with or without plasma-pretreatment reveled that the key of the enhancement of NOx conversion on CuZSM-5 was the removal of NOx species present at Cu site by plasma-pretreating CuZSM-5.

关 键 词：CuZSM-5 程序升温脱附 介质阻挡放电 氮氧化物 

分 类 号：O647.31[理学—物理化学]