Novel Mn-Ce bi-oxides loaded on 3D monolithic nickel foam for low-temperature NH_(3)-SCR de-NO_(x):Preparation optimization and reaction mechanism  

作　　者：Shuquan Ni Xiaolong Tang Honghong Yi Fengyu Gao Chengzhi Wang Yiran Shi Runcao Zhang Wenjuan Zhu 

机构地区：[1]School of Energy and Environmental Engineering,University of Science and Technology Beijing,Beijing 100083,China [2]Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants,Beijing 100083,China

出　　处：《Journal of Rare Earths》2022年第2期268-278,I0003,共12页稀土学报（英文版）

基　　金：Project supported by the National Key R&D Program of China(2017YFC0210303);National Natural Science Foundation of China(21806009);China Postdoctoral Science Foundation(2019T120049);Fundamental Research Funds for the Central Universities(06500152,FRF-TP-18-019A1)。

摘　　要：This study explored the superior citrate method(CM)to synthesize Mn-Ce bi-oxides on 3 D monolithic Ni-foam(NF)catalysts for the selective catalytic reduction of NO by NH_(3)(NH_(3)-SCR).The 17 wt%Mn(7)Ce(3)O_(x)/NF(CM-17)catalyst shows the NO_(x)conversion of 98.7%at 175℃and 90%in the presence of 10 vol%H2 O.It is revealed that the combination of surface-active oxygen(formed by high-level oxygen vacancies)and strongly oxidized Mn4+species promots the Fast-SCR reactions,in which Mn4+species play a leading role in NH_(3)-SCR reaction,and the unsaturated Ni atoms and also Ce3+species promote electron exchange and thus improve the redox performance.The coexistence mechanisms of Fast-SCR reactions and E-R pathways are observed over Mn-CeO_(x)/NF catalyst,which may be promoted by the Br?nsted sites at low temperature.In addition,the heat resistance,stability,3 D monolithic porous structure and excellent physical properties of foam nickel provide a unique growth substrates for catalysts preparation and reaction sites for NO_(x)purification.Therefore,industrial application of Mn-Ce bioxides loaded on 3 D monolithic is proposed to be achieved through reasonable preparation methods.

关 键 词：NH_(3)-SCR Low temperature Citrate method Fast-SCR 3D monolithic catalysts Oxygen vacancies 

分 类 号：O643.36[理学—物理化学] X701[理学—化学]