介质阻挡放电与CuZSM-5结合方式对脱除NO_x的影响  

Effect of Combination Way of Dielectric Barrier Discharge and CuZSM-5 on NO_x Removal

作　　者：陈刚[1] 孙琪[1,2] 石雷[1] 牛金海[2] 宋志民[2] 

机构地区：[1]辽宁师范大学化学化工学院,辽宁大连116029 [2]大连理工大学等离子体物理化学实验室,辽宁大连116024

出　　处：《催化学报》2010年第7期817-821,共5页

基　　金：国家自然科学基金(20077005);辽宁省自然科学基金(20072154);辽宁省高校创新团队资助项目(2008T106)

摘　　要：研究了介质阻挡放电(DBD)与CuZSM-5结合方式,即DBD和CuZSM-5两段分置(两段法)或将CuZSM-5放入DBD区(一段法),对脱除氮氧化物的影响.结果表明,在NO/N2或NO/C2H4/N2无氧体系中,DBD与CuZSM-5结合产生的协同效应很小;在NO/O2/N2富氧体系中,DBD与CuZSM-5结合导致氮氧化物转化率下降;而在NO/C2H4/O2/N2富氧体系中,在250oC,空速12000h-1,输入放电能量密度(Ein)155J/L的条件下,单纯催化、单纯等离子体放电、一段法和两段法时氮氧化物转化率分别为39%,1.5%,79%和52%.两段法产生了中等程度的协同效应,主要是第一段等离子体放电产生新稳态物种(如NO2,CO和CO2等)起作用;而一段法产生的协同效应较大,主要是由于等离子体放电产生的新稳态物种和激发态短寿命物种(如N2*,NO*,CH和CN等)共同起作用.The effect of the combination way of dielectric barrier discharge（DBD） stage filled with fused silica pellets and a CuZSM-5 catalyst on NOx removal was investigated by one-stage plasma-over-catalyst（POC） and two-stage plasma-followed-by-catalyst（PFC） reactors.In the NO/N2 or NO/C2H4/N2 system,there was a small synergistic effect between DBD plasmas and CuZSM-5 using the one-stage POC and the two-stage PFC reactors.The NOx conversion from the one-stage POC reactor or the two-stage PFC reactor decreased in the NO/O2/N2 system.Under the conditions of the reaction mixture of NO,C2H4,O2,and N2,gas hourly space velocity of 12 000 h^-1,the input discharge energy density（Ein） of 155 J/L,and 250 ℃,the NOx conversions in the systems of pure catalyst,pure plasma,plasma-catalyst combination in a one-stage POC reactor,and a two-stage PFC reactor were 39%,1.5%,79%,and 52%,respectively.The observed moderately plasma-enhanced NOx conversion in the two-stage reactor was attributed to the stable species such as NO2,CO,and CO2 formed in its first discharge stage.Both short-lived active species（such as N2＊,NO＊,CH,and CN） and stable species formed from the plasma-induced or plasma-catalytic process in the one-stage reactor may be responsible for the significant synergistic effect between the DBD plasmas and CuZSM-5 catalyst.

关 键 词：氮氧化物 介质阻挡放电 发射光谱 协同效应 铜 ZSM-5分子筛 

分 类 号：O643.36[理学—物理化学]