摘要
评价了Ag/SAPO 3 4分子筛催化剂选择性还原NO的活性 ,并运用漫反射红外光谱原位研究NO在Ag/SAPO 3 4催化剂上的选择性催化还原机理 .结果表明Ag/SAPO 3 4有良好的低温活性 ,在氧气浓度为 3 6%和温度为 5 73K～ 673K时NO还原成N2 的转化率达 70 % ;催化剂活性随C3H6 浓度的增加而升高 ,随空速的增加而稍有下降 .基于漫反射红外光谱 ,认为反应机理为 :NO、丙烯和氧反应 ,在Ag/SAPO 3 4催化剂上生成吸附的有机 氮氧化物 ,再由这些吸附物种分解成N2 ,催化还原的关键是形成有机 氮氧化物中间体 .氧的作用是充分促进丙烯活化以及增加NOx 吸附态含量 ,并且氧的存在是有效产生一系列中间物不可缺少的条件 .
The activity of Ag/SAPO 34 molecular sieve catalyst was investigated,and the selective catalytic reduction(SCR) of NO was studied by in situ diffuse reflectance FTIR spectroscopy(DRIFTS). The results show that the prepared catalyst had high activity at low temperature and the conversion of NO reduction to N 2 was about 70% at 3 6%O 2 and 573K～673K of temperature.The catalysis activity rised with the concentration of C 3H 6 but light decrease with GHSV. Based on in situ DRIFTS, a reaction mechanism was proposed that NO, propene and oxygen react to form organo nitro and organo nitro adsorbed species as key intermediates, then these intermediates were decompose to nitrogen. NO and propene were easily activated in oxygen. Furthermore, the presence of oxygen is necessary to form a series of intermediates.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2002年第6期22-25,共4页
Environmental Science
基金
国家自然科学基金资助项目 (2 0 0 76 0 17)
广东省自然科学基金资助项目 (980 5 12
0 0 0 4 2 8)
广东省环保局科技研究开发项目 .
