含锰储氧材料的制备与性能研究-环境科学专业论文.docxVIP

四川大学硕t学位论文Preparation 四川大学硕t学位论文 Preparation and Research of Manganese Content Oxygen Storage Materials Major：Environmental Science Postgraduate：Liu Ping Supervisor：Chen，Yaoqiang Since manganese possesses precise redox properties，Mn content oxygen storage material(OSM)is a key mamrial of automobile exhaust gas purification．In this paper,the preparation and properties of Mn content OSM were studied in detail．A serial of Mn content OSM were precipitated with ammonia-ammonium mixed solution and characterized by BET、Oxygen pulse adsorption、X-ray diffraction (XRD)、temperature programmed reduction frPR)and thermal gravity(田G)．The modification of the textural and structural properties、oxygen storage capacity、 redox behavior and change in phase were investigated．An em【phasized investigation was carried on the effects of Mn doped content on the properties of CeOz-based oxygen storage materials． The results show that the oxygen storage capacity(OSC)and reduction performance of the fresh Ce··Zr-Mn-·O solid solution are improved with Mn contem added．The samples dominate internal phase oxygen storage and keep large OSC while its surface area is in the extreme small after aged at 1000℃．The fresh sample presents phase segregation when Mn content reaches O．3(mole fraction)． The effects of Mn dopant on the Ce—Zr-Y-O compound oxides are investigated in detail．The results reveal that appropriately doping Mn with Ce-Zr solid solution can improve the thermal stability of the samples and decrease the reducible temperature of the OSM．The crystal particle size of the samples grows and Ⅲ 四川大学硕十乍位论史thermal 四川大学硕十乍位论史 thermal stability decreases with increasing Mn content．The sample indicates the highest OSC and excellent property of thermal stability when manganese content (mole fraction)is 0．025，its surface area reaches highly 57．8m2／g after aged 5h at 1000℃． The effects of trivalent dopants on the Ce04Zro 55Mn00502 solid solution ale investigated in detail．The results reveal that the samp