摘要
将In/HZSM-5催化剂填充于介质阻挡放电反应器中,考察了甲烷参与下Nox的脱除及其脱除产物. 结果表明,在200～350 ℃间,等离子体与催化剂共同作用时Nox的转化率明显高于等离子体或催化剂单独作用时Nox的转化率. 在0.03%NO-0.05%CH4-2%O2-97.92%N2,空速7 200 h-1 和300 ℃的条件下,单纯等离子体、单纯催化剂和二者共同作用下Nox的转化率分别为24%,25%和65%. 甲烷参与下等离子体和催化剂共同作用时,在催化剂表面没有硝酸盐或亚硝酸盐生成,仅有少量副产物N2O生成. 由此可以推断,Nox脱除的主要产物为N2. 低于300 ℃时,Nox的脱除以分解途径为主,甲烷的作用主要是抑制放电条件下Nox生成的副反应; 在300～350 ℃间,甲烷作为还原剂被等离子体和催化剂协同活化,Nox的脱除以还原途径为主. 采用催化剂填充型介质阻挡放电反应器,可在非常宽的温度区间实现Nox的脱除.
In the In/HZSM-5 catalyst-pellet-filled dielectric barrier discharge reactor, the NOx removal with methane additive and its products were investigated. At 200-350 ℃ , in the process of plasma with In/HZSM- 5 catalyst, the NOx conversion was much higher than that in the process of plasma alone or In/HZSM-5 catalyst alone. Under the reaction conditions of 0.03 % NO-0.05 % CH4-2 % 02-97.92 % N2, GHSV = 7 200 h^- 1 and θ = 300 ℃ , the NOx conversion for pure plasma induced, pure catalyst induced and plasma-catalyst induced reactions was 24 % , 25 % and 65 %, respectively. No nitrate salt or nitrite salt was observed on the catalyst surface. N2O as a by-product was only formed in minority. Thereby, it was inferred that N2 was the major product in the plasma-catalyst induced NO, removal with methane additive. At below 300 ℃ , the NO, removal proceeded mainly via decomposition pathway and methane played an important role in restraining NOx formation. At 300 -350 ℃ , methane could be activated by the synergetic effect of plasma and In/HZSM-5 catalyst and reacted as a reductant, which led to NOx removal via reduction pathway. Using such a catalyst-pellet-filled dielectric barrier discharge reactor, NOx could be removed in a very broad temperature range （for low temperature zone by plasma-catalyst; for high temperature zone by catalyst alone）.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2005年第9期803-808,共6页
基金
国家高技术研究发展计划(863计划)(2002AA649140)
国家自然科学基金(20077005)
辽宁省科学技术基金(20022112)资助项目.
