Enhanced hydrothermal stability of Cu-SAPO-34 with an ultrathin TiO_(2)coated by atomic layer deposition for NH3-SCR  

作　　者：TIAN HeYuan XI WenChang ZHANG YiBo SUN LiWei LIU Peng WU Fan YANG Guo GUO Feng YANG XiangGuang 

机构地区：[1]State Key Laboratory of Rare Earth Resource Utilization,Jilin Province Key Laboratory of Green Chemistry and Process,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022,China [2]School of Applied Chemistry and Engineering,University of Science and Technology of China,Hefei 230026,China [3]College of Materials Sciences and Engineering,Henan Institute of Technology,Xinxiang 453000,China [4]Ganjiang Innovation Academy,Chinese Academy of Sciences,Ganjiang 341000,China

出　　处：《Science China(Technological Sciences)》2022年第10期2325-2336,共12页中国科学（技术科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.22072141,22176185,and 22002150);the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2018263);the Key Research Program of the Chinese Academy of Sciences(Grant No.ZDRW-CN-2021-3);the Self-deployed Projects of Ganjiang Innovation Academy,Chinese Academy of Sciences(Grant No.E055C003)。

摘　　要：Reducing pollution and carbon emissions is an important step toward peaking CO_(2)emissions before 2030 and reaching carbon neutrality before 2060,and heavy diesel vehicle pollution,particularly nitrogen oxides(NOx)emissions,is an essential part.CuSAPO-34 is a CHA-type small pore molecular sieve with excellent ammonia(NH_(3))selective catalytic reduction(NH_(3)-SCR)catalytic activity,but it cannot be stored or applied because of severe degradation caused by low-temperature hydrothermal aging.To improve the hydrothermal stability,TiO_(2)was coated on the surface of Cu-SAPO-34 by the ALD method to form a uniform nanolayer.Though this ultrathin TiO_(2)nanolayer has little effect on NH_(3)-SCR catalytic activity of Cu-SAPO-34,the resistance to low-temperature hydrothermal aging in liquid water at 80℃for 24 h has greatly been improved.A study carried out by SEM,XRD,NH_(3)-TPD,and EPR,showed that the ultra-thin TiO_(2)nanolayers were covered uniformly and hydrolysis of frameworks silicon and the migration of Cu^(2+)was retarded.This method has some implications for the future preparation of highly robust Cu-SAPO-34 catalysts for industrial applications.This research could inspire the development of highly robust CuSAPO-34 catalysts to control the NOx emissions from diesel engines.

关 键 词：selective catalytic reduction chabazite zeolite catalyst Cu-SAPO-34 low-temperature hydrothermal stability atomic layer deposition 

分 类 号：TG174.4[金属学及工艺—金属表面处理]