Cu-SSZ-13与Fe-β混合催化剂上NH_(3)-SCR性能研究  

Study on NH_(3)-SCR Performance over Cu-SSZ-13 and Fe-β Mixed Catalysts

作　　者：李渊[1] 侯宇坤 赵立国 谭小耀[1] LI Yuan;HOU Yukun;ZHAO Liguo;TAN Xiaoyao(School of Chemical Engineering and Technology Tiangong University,Tianjin 300387,China)

机构地区：[1]天津工业大学化学工程与技术学院,天津300387

出　　处：《材料导报》2022年第19期55-59,共5页Materials Reports

基　　金：国家自然科学基金(91745116)。

摘　　要：铜改性SSZ-13分子筛(Cu-SSZ-13)是一种高效的去除NO_(x)的NH_(3)选择性还原催化剂,但是Cu-SSZ-13的高温(>400℃)脱硝活性欠佳。相比Cu-SSZ-13,铁改性β分子筛催化剂(Fe-β)价格便宜且高温脱硝性能较好,因而Fe-β也备受人们关注。虽然掺杂铜后,Fe-β催化剂的低温活性有所提高,但是其对NO_(x)脱除的低温活性温度窗口还有待拓宽,最高脱除率还有待提高。本工作拟通过Cu-SSZ-13与Fe-β的机械混合制得复合催化剂,以拓展催化剂的温度窗口。在商用SSZ-13的基础上,通过离子交换不同浓度的硝酸铜溶液制备了Cu-SSZ-13。氨气选择性催化还原(Ammonia selective catalytic reduction,NH_(3)-SCR)测试表明交换液为0.04 mol/L的硝酸铜溶液时所制备的Cu-SSZ-13的脱硝活性最好,200~400℃NO_(x)脱除率接近100%。利用粉末X射线衍射(XRD)、电子扫描显微镜(SEM)等一系列手段对催化剂进行了表征。结果表明:机械混合Cu-SSZ-13+Fe-β对Cu-SSZ-13的NH_(3)-SCR低温活性窗口影响不大,但对其高温脱硝性能有较大提高。Copper modified SSZ-13 molecular sieve(Cu-SSZ-13)is an efficient NH_(3) selective reduction catalyst for NO_(x) removal,but the NO_(x) removal activity of Cu-SSZ-13 at high temperature(>400℃)is poor.Compared with Cu-SSZ-13,Fe modifiedβmolecular sieve catalyst(Fe-β)is cheaper and has better denitration performance at high temperature,so Fe-βhas attracted much attention.The low temperature activity of Fe-βcatalyst is improved after Cu doping,but cryogenic active temperature window and the maximum removal rate of SCR denitration catalyst still need to be improved.In this work,the composite catalyst was prepared by mechanical mixing of Cu-SSZ-13 and Fe-βto expand the temperature window of the catalyst.Cu-SSZ-13 was prepared by ion exchange of different concentrations of Cu(NO_(3))_(2) solution with commercial SSZ-13.The NH_(3)-SCR test results show that Cu-SSZ-13 prepared by exchange of Cu(NO_(3))_(2) solution with the concentration of 0.04 mol/L has the best denitration activity,and the NO_(x) removal rate is close to 100%at 200—400℃.The catalysts were characterized by powder X-ray diffraction(XRD),electron scanning microscope(SEM)and a series of other means.Reaction performance test results show that mechanical mixing of Cu-SSZ-13+Fe-βdoes not affect the low temperature activity window of NH_(3)-SCR of Cu-SSZ-13,but the high temperature performance of catalyst is improved after mechanical mixing.

关 键 词：Fe-β Cu-SSZ-13 机械混合 氨气选择性催化还原 

分 类 号：O643.36[理学—物理化学]