La ions-enhanced NH_(3)-SCR performance over Cu-SSZ-13 catalysts

作     者：Mengyang Chen Wenru Zhao Yingzhen Wei Jinfeng Han Junyan Li Chang Sun Donghai Mei Jihong Yu Mengyang Chen;Wenru Zhao;Yingzhen Wei;Jinfeng Han;Junyan Li;Chang Sun;Donghai Mei;Jihong Yu

作者机构：State Key Laboratory of Inorganic Synthesis and Preparative ChemistryCollege of ChemistryJilin UniversityChangchun 130012China School of Materials Science and EngineeringTiangong UniversityTianjin 300387China International Center of Future ScienceJilin UniversityChangchun 130012China 

出 版 物：《Nano Research》 (纳米研究（英文版）)

年 卷 期：2023年第16卷第10期

页      面：12126-12133页

核心收录：

学科分类：07[理学] 070304[理学-物理化学(含∶化学物理)] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0702[理学-物理学] 

基　　金：the National Natural Science Foundation of China(Nos.22288101,21920102005,and 21835002) the 111 Project(No.B17020)for supporting this work. 

主　　题：zeolite bimetallic catalyst Cu-SSZ-13 lanthanum ammonia selective catalytic reduction(NH_(3)-SCR) 

摘      要：Lanthanum(La)ions are generally recognized to cause a decline of the catalytic performance for Cu-SSZ-13 zeolite in the selective catalytic reduction of NO_(x)with NH_(3)(NH_(3)-SCR).Herein,we demonstrate that the NH_(3)-SCR performance and hydrothermal stability of Cu-La-SSZ-13 zeolites can be enhanced with the incorporation of a small amount of La ions.The incorporation of La ions into SSZ-13 favors more Z_(2)Cu^(2+)ions at six-membered rings(6MRs),which results in higher hydrothermal stability of Cu-La-SSZ-13 than that of Cu-SSZ-13.The NO conversion of Cu-La-SSZ-13 achieves 5%–10%higher than that of Cu-SSZ-13 at the temperature range of 400–550℃ after hydrothermal ageing.While introducing excess amount of La ions in SSZ-13 may cause the formation of inactive CuO_(x),leading to the decrease of catalytic activity and hydrothermal stability.Notably,the low-temperature activity of Cu-SSZ-13 with a low Cu content(≤2 wt.%)can be boosted by the introduction of La ions,which is largely due to the improved redox ability of Cu active sites modified by La ions.Density functional theory(DFT)calculations indicate that La ions prefer to locate at eight-membered rings(8MRs)and thus promoting the formation of more Z_(2)Cu^(2+)ions.Meanwhile,the existence of La ions in SSZ-13 inhibits the dealumination process and the transformation from Z_(2)Cu^(2+)to CuO_(x),resulting in its enhanced hydrothermal stability.The present work sheds a new insight into the regulation of secondary metal cations for promoting high NH_(3)-SCR performance over Cu-SSZ-13 zeolite catalysts.