Novel Mn-Ce bi-oxides loaded on monolithic nickel foam for low-temperature NH3-SCR de-NOx:Preparation optimization and reaction mechanism

• 作者: Shuquan Ni Xiaolong Tang Honghong Yi Fengyu Gao Chengzhi Wang Yiran Shi Runcao Zhang Wenjuan Zhu
• 来源期刊: 稀土学报（英文版）
• 年，卷（期）: 2022,（2）
• 所属期刊栏目: RARE EARTH CATALYSIS
• 页码范围: 268-278
• 页数: 11页
• 语种: 英文

摘要

This study explored the superior citrate method (CM) to synthesize Mn-Ce bi-oxides on 3D monolithic Ni-foam (NF) catalysts for the selective catalytic reduction of NO by NH3 (NH3-SCR).The 17 wt％ Mn(7)Ce(3)Ox/NF (CM-17) catalyst shows the NOx conversion of 98.7％ at 175 ℃ and 90％ in the presence of 10 vol％ H2O.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 NH3-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-CeOx/NF catalyst,which may be promoted by the Brφnsted sites at low temperature.In addition,the heat resistance,stability,3D monolithic porous structure and excellent physical properties of foam nickel provide a unique growth substrates for cat-alysts preparation and reaction sites for NOx purification.Therefore,industrial application of Mn-Ce bi-oxides loaded on 3D monolithic is proposed to be achieved through reasonable preparation methods.