sapo分子筛应用于选择性催化还原nox的研究化学工程与技术专业论文.docxVIP

北京化工大学硕士学位论文分Cu2+的量就越大，从而催化剂的低温SCR活性表现就越好。 北京化工大学硕士学位论文 分Cu2+的量就越大，从而催化剂的低温SCR活性表现就越好。 用两种不同的模板剂制备得到了Si分布均匀和由大量Si岛存在 的SAPO一34分子筛，并利用离子交换法将他们制备成Cu／SAPO．34 催化剂，对他们的SCR催化活性进行了研究。Si分布均匀的产品表 现出了优异的SCR催化活性和N2选择性，而有大量Si岛存在的样 品在低温处活性表现尚可，在高温处活性急剧下降，同时在高温处有 大量N20副产物生成。这说明Cu基SAPO分子筛催化剂中Si岛的 存在不利于SCR催化反应。 将Cu／SAPO一34与Cu／SAPO．35进行了对比研究分析了 Cu／SAPO．34与Cu／SAPO一35催化效果差异的原因。SAPO．34分子筛 强酸位酸强度要明显高于于SAPO一35。样品的SCR活性分析显示 Cu／SAPO．35相比于Cu／SAPO．34低温活性较差，而高温可以保持更 高的催化活性。研究认为这可能与Cu物种在SAPO．35上稳定性较好， 还原性较弱有关系。 关键词：SAPO一34，SAPO．35，SCR 万方数据 STUDY STUDY oN SELECTIVE CATALYTIC REDUCTIoN oF NoX BY SAPo ZEoLITES ABSTRACT As one of the main components of atmospheric pollutants，NOx has brought great harm to people’S health，and how to eliminate NOx become one of the focuses of research in recent years．Among the NOx control methods at present，selective catalytic reduction(SCR)with its high removal efficiency,less by—products，the advantages of mild reaction conditions become the direction of future development．To prepare catalyst with the high activity,good selectivity and low price become the core and key of SCR research．During this research，through a large number of experiments we get two excellent activity of SCR catalyst Cu／SAPO一35 and Cu／SAPO一34，besides the influence factors of preparing catalysts，the SCR catalytic activities were studied comprehensively． The SAPO一3 5 zeolites synthesised using HMI as template，wim the increase of Si content in the sol the zeolite crystallinity increased．At the same time SM3 substitution reaction of Si gradually happen，eventually lead to a small amount of Si island growed in the zeolites．Acdity of the zeolites firstly increase then decrease with the increase of Si quantity． 1II 万方数据 万方数据 万方数据 北京化工大学硕上学位论文Preparring 北京化工大学硕上学位论文 Preparring Cu／SAPO一3 5 catalysts by rotating impregnation method and ion exchange method，then evaluate their SCR activities．We found that the Cu／SAPO一3 5 samples prepared by the rotating impregnation method have a good low temperature acti