铜含量对Cu-SAPO-34催化剂NH_(3)选择性催化还原NO_(x)的影响  

The effect of copper loading on NH_(3) selective catalytic reduction of NO_(x) over Cu-SAPO-34 catalysts

作　　者：张天天 刘洋[2] 张恒 郝彦衡 侯坤明 韩丽峰 曾尚红[2] 王艳[1,2] ZHANG Tiantian;LIU Yang;ZHANG Heng;HAO Yanheng;HOU Kunming;HAN Lifeng;ZENG Shanghong;WANG Yan(Baotou Research Institute of Rare Earths,Inner Mongolia Baotou 014030,China;School of Chemistry and Chemical Engineering,Inner Mongolia University,Hohhot 010051,China)

机构地区：[1]包头稀土研究院,内蒙古包头014030 [2]内蒙古大学化学化工学院,呼和浩特010051

出　　处：《内蒙古工业大学学报（自然科学版）》2024年第3期229-238,共10页Journal of Inner Mongolia University of Technology：Natural Science Edition

基　　金：国家自然科学基金项目(21968020);中国北方稀土(集团)高科技有限公司科技项目(BFXT-2021-D-0022);白云鄂博稀土资源研究与综合利用全国重点实验室自主课题(BFXT-2022-D-0043)。

摘　　要：针对分子筛催化剂低温活性不佳的问题,采用一锅法原位合成了具有不同Cu负载量的Cu-SAPO-34催化剂,研究了催化剂的表面性质、Cu物种分布及种类对Cu-SAPO-34低温活性的影响,探究了NH_(3)选择性催化还原NO_(x)(NH_(3)-SCR)的反应机理。研究结果表明,原位合成有利于SAPO-34骨架稳定,适量的Cu可以使所制备的催化剂具有多级孔道结构并以微孔为主导,有利于SCR反应。丰富的ZCuOH位点和稳定的酸位使0.2 Cu-SAPO-34催化剂具有优异低温SCR活性。经过机理分析发现,SCR反应在0.2 Cu-SAPO-34催化剂上遵循Eley-Rideal和Langmuir-Hinshelwood两种反应机理,并且在低温端时Eley-Rideal机理占主导地位。To address the problem of poor low-temperature activity of molecular sieve catalysts,Cu-SAPO-34 catalysts with different Cu loadings were synthesized in situ by a one-pot method,and the effects of catalyst surface properties,Cu species distribution and species on the low-temperature activity of Cu-SAPO-34 were analyzed.Furthermore,the reaction mechanism of NH_(3) selective catalytic reduction of NO_(x)(NH_(3)-SCR)were investigated.The results show that in situ synthesis is beneficial to SAPO-34 framework stabilization,and the appropriate amount of Cu can make the prepared catalysts to possess a multi-level pore structure dominated by micropores,which is beneficial to SCR reaction.The abundant ZCuOH sites and stable acid sites give the 0.2 Cu-SAPO-34 catalyst excellent low-temperature SCR activity.After mechanistic analysis,SCR reactions over 0.2 Cu-SAPO-34 catalysts both followed the Eley-Rideal and Langmuir-Hinshelwood reaction mechanisms,and the Eley-Rideal mechanism is dominant at low temperatures.

关 键 词：NH_(3)-SCR Cu-SAPO-34 活性物种 反应机理 

分 类 号：TK448.21[动力工程及工程热物理—动力机械及工程]