Fe、Mn对CeO_(2)(111)面NH_(3)/NO吸附及SCR催化性能的影响  

Promotion Effects of Fe and Mn Doping on NH_(3)/NO Adsorption and NH3-SCR Catalysis of CeO_(2)(111) Surface

作　　者：罗慧娟 张露 龚志军[1,2,3] 张凯 武文斐[1,2,3] LUO Hui-juan;ZHANG Lu;GONG Zhi-jun;ZHANG Kai;WU Wen-fei(School of Energy and Environment,Inner Mongolia University of Science and Technology,Baotou 014010,China;Key Laboratory of Efficient and Clean Combustion,Inner Mongolia University of Science and Technology,Baotou 014010,China;China Key Laboratory of Integrated Exploitation of Bayanobo Multi-metal Resources,Baotou 014010,China)

机构地区：[1]内蒙古科技大学能源与环境学院,内蒙古包头014010 [2]内蒙古科技大学高效洁净燃烧重点实验室,内蒙古包头014010 [3]白云鄂博矿多金属资源综合利用国家重点实验室,内蒙古包头014010

出　　处：《稀土》2022年第3期41-50,I0004,共11页Chinese Rare Earths

基　　金：国家自然科学基金项目(51866013);内蒙古自然科学基金项目(2018LH05013);内蒙古科技大学创新基金项目(2017QDL-B16)。

摘　　要：CeO_(2)具有一定的催化还原、储存释放氧的能力,是潜在的低温NH_(3)-SCR催化脱硝材料。探究本征CeO_(2)和改性CeO_(2)的脱硝机理,对开发高性能催化剂具有重要意义。本论文将研究Fe、Mn掺杂CeO_(2)(111)面对NH_(3)-SCR反应气体NH、NO的吸附行为,分析Fe、Mn掺杂对CeO_(2)催化脱硝机理的影响。研究发现,Fe、Mn掺杂均促进CeO_(2)(111)面对NH的吸附,分别伴随着一个和三个N—H键的解离。Fe、Mn掺杂也增强了CeO_(2)(111)面O活性位点对NO的吸附。CeO_(2)(111)面及Fe、Mn掺杂CeO_(2)(111)面NO2结构的稳定形成,表明L-H机制始终占主导地位。Fe、Mn掺杂改变了晶面原子的化学反应性和电子转移能力,降低了NH的N—H键解离能,降低了反应能垒,增强了吸附体系的催化活性。Mn掺杂改性时,三个N—H键的解离表明副产物2O容易生成,将降低催化反应的N2选择性。CeO_(2) has the ability of catalytic reduction, storage and release of oxygen, which is a potential material for low temperature NH_(3)-SCR catalytic denitration. It is of great significance to explore the denitration mechanism of intrinsic CeO_(2) and modified CeO_(2) for the development of high performance catalysts. In this paper, the adsorption behavior of Fe and Mn doped CeO_(2)(111) surface on NH_(3)-SCR reaction gases NHand NO was studied, and the effect of Fe and Mn doping on the catalytic denitration mechanism of CeO_(2) was analyzed. It was found that Fe and Mn doping promoted the adsorption of NHon CeO_(2)(111) surface, accompanied by the dissociation of one and three N—H bonds, respectively. Fe and Mn doping also enhanced the adsorption of NO on the surface of CeO_(2)(111). The stable formation of NOstructure on CeO_(2)(111) surface and Fe, Mn doped CeO_(2)(111) surface indicates that L-H mechanism is always dominant. Fe and Mn doping changed the chemical reactivity and electron transfer ability of surface atoms, reduced the N—H bond dissociation energy of NH, reduced the reaction energy barrier, and enhanced the catalytic activity of the adsorption system. The dissociation of three N—H bonds indicates that the N2O by-product is easy to form, which will reduce N2 selectivity of the NH_(3)-SCR catalysis.

关 键 词：CeO_(2) Fe、Mn掺杂 低温NH_(3)-SCR 密度泛函理论计算 NH3解离 

分 类 号：TQ133.31[化学工程—无机化工]