摘要
以白云鄂博矿中的独居石为催化材料的载体,采用硝酸铁溶液浸渍、马弗炉焙烧获得一系列矿物催化材料。采用X射线晶体衍射(XRD),扫描电镜(SEM),比表面积分析(BET),X射线荧光光谱分析(XRF),氨气程序升温脱附(NH_(3)-TPD),X射线电子能谱(XPS)以及原位红外(in-situ DRIFTS)等手段对催化剂进行相关的表征分析,在微型反应器中评估和比较了不同样品的脱硝活性。结果表明,在硝酸铁溶液浓度为0.5 mol·L^(-1)时,独居石负载Fe_(2)O_(3)的活性粉体的脱硝效率最佳。反应温度为300℃时,脱硝效率可达80.52%。研究表明负载Fe后矿物表面大量裂纹与孔洞,比表面积增大;且大部分Fe_(2)O_(3)以高分散或无定形状态嵌布在独居石上,形成了少部分的铁铈复合氧化物。XPS表明催化材料中Ce^(3+),Fe^(2+)所占比例最高,并具有大量酸性位,表面吸附NH_(3)的能力逐渐提升,从而提高矿物催化材料脱硝活性;催化剂的NH_(3)选择性催化还原(NH_(3)-SCR)反应遵循Eley-Rideal(E-R)机制和Langmuir-Hinshelwood(L-H)机制,在NO还原过程中,NH_(3)对反应中间体具有选择性,在低温下优先与单齿硝酸盐反应。
Nitrogen oxides(NOx)was one of the main components of photochemical smog and acid rain,and it also destroyed the ozone layer.Therefore,the control and emission of nitrogen oxides were urgent problems to be solved in front of us.The application of NH_(3)as reducing agent in selective catalytic reduction was widely used in denitrification because of its high efficiency and mature tech⁃nology.Thus,the development and development of efficient catalysts were the core of NH_(3)selective catalytic reduction(NH_(3)-SCR)technology.China was a recognized rare earth country in the world,in which monazite was a phosphate mineral containing rare earth metals and consisted of Ce(PO_(4))or(Ce,Y,La)[PO_(4)].The proportion of rare earth content in monazite can reach 38%,of which the proportion of Ce elements was 21%,which can provide support for active components and improve the stability of active components.At the same time,it can provide appropriate surface area and pore size for the catalysts,which was beneficial to the joint action be⁃tween rare earth elements and polymetallic.A series of mineral catalytic materials were obtained by impregnation of ferric nitrate solu⁃tion and roasting in muffle furnace,giving full play to the polymetallic synergistic effect between mineral phases,and making scientif⁃ic and effective use of rare earth resources in Baiyan Obo.It was of great significance for the development of clean green,efficient and comprehensive application technology of rare earth based mineral catalytic materials.The structure,surface morphology,properties and catalytic mechanism of the catalyst were characterized and analyzed by X-ray diffraction analysis(XRD),microscope analysis,scanning electron microscope(SEM),Brunauer-Emmett-Teller(BET),X-ray Fluorescence Spectrometer(XRF),Ammonia tempera⁃ture-programmed desorption(NH_(3)-TPD),X-ray photoelectron spectroscopy(XPS)and in situ diffuse reflectance infrared transform spectroscopy(in situ DRIFTS),and the denitrification activity of different samples was evalua
作者
赵然
王莹
赵增武
武文斐
张凯
Zhao Ran;Wang Ying;Zhao Zengwu;Wu Wenfei;Zhang Kai(College of Material and Metallurgy,Inner Mongolia University of Science&Technology,Baotou 014010,China;State Key Laboratory of Multi-Metal Resources Comprehensive Utilization,Baiyun Obo Mine,Inner Mongolia Au-tonomous Region,Baotou 014010,China;School of Energy and Environment,Inner Mongolia University of Sci-ence and Technology,Baotou 014010,China)
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2022年第7期913-925,共13页
Chinese Journal of Rare Metals
基金
国家自然科学基金项目(22068029)
内蒙古自治区自然科学基金项目(2021LHMS02003,2019MS05050)
稀土资源利用国家重点实验室开放课题(RERU2021010)
内蒙古冶金、能源与资源高效利用科技创新团队建设资助。
关键词
独居石
催化脱硝
矿物催化
原位红外
monazite
catalytic denigration
mineral catalysis
in situ infrared
