共沉淀法制备高热稳定性铈锆复合氧化物的工艺优化及其储放氧性能  

Preparation of CeO_(2)-ZrO_(2)mixed oxides with high thermal stability and their oxygen storage/release capacities

作　　者：孙琪 周媛媛 桑其州 高睿 唐贤睿 倪兆菁 王晓丽 万杰 吴功德[1] 周仁贤[4] SUN Qi;ZHOU Yuanyuan;SANG Qizhou;GAO Rui;TANG Xianrui;NI Zhaojing;WANG Xiaoli;WAN Jie;WU Gongde;ZHOU Renxian(Energy Research Institute,Nanjing Institute of Technology,Nanjing 211167,Jiangsu,China;School of Materials Science and Engineering,Ocean University of China,Qingdao 266100,Shandong,China;School of Environmental Engineering,Nanjing Institute of Technology,Nanjing 211167,Jiangsu,China;Institute of Catalysis,Zhejiang University,Hangzhou 310028,Zhejiang,China)

机构地区：[1]南京工程学院能源研究院,江苏南京211167 [2]中国海洋大学材料科学与工程学院,山东青岛266100 [3]南京工程学院环境工程学院,江苏南京211167 [4]浙江大学催化研究所,浙江杭州310028

出　　处：《工业催化》2024年第11期43-51,共9页Industrial Catalysis

基　　金：国家重点研发计划项目(2022YFB3504200);江苏省创新支撑计划项目(BZ2022053);安徽省重点研发计划项目(202104g01020006);江苏省大学生创新创业训练计划项目(202311276007Z)。

摘　　要：铈锆复合氧化物是汽车尾气净化三效催化剂的关键组分之一。日益严格的排放法规对铈锆复合氧化物的热稳定性提出了更高的要求。通过共沉淀法合成高热稳定性CeO_(2)-ZrO_(2)复合氧化物,考察掺杂改性元素、前驱体盐种类、洗涤方法以及陈化条件对样品比表面积和热稳定性的影响。结果表明,采用La-Y-Nd共掺杂作为改性组分,以含Ce^(4+)的Ce(NH_(4))_(2)(NO_(3))_(6)作为铈盐前驱体,采用无水乙醇洗涤,在乙醇环境陈化12 h得到的CeO_(2)/ZrO_(2)/La_(2)O_(3)/Y_(2)O_(3)/Nd_(2)O_(3)(CZLYN)样品具有最优的比表面积与热稳定性,经马弗炉1050℃老化12 h后仍能维持38 m^(2)·g^(-1)的比表面积。将优化工艺下制备的CZLYN样品与某进口商用铈锆粉进行表征对比,发现其与商用铈锆粉具有相似的物相结构、晶粒尺寸、孔径分布和表面微观形貌,且新鲜样比表面积提高约60%;经过1050℃马弗炉热老化后,优化工艺CZLYN样品比表面积较商用铈锆粉提高约20%;水热老化后,优化工艺CZLYN样品比表面积仍略高于进口商用铈锆粉,动态储放氧性能高约30%,表明其具有更为优异的热稳定性。CeO_(2)-ZrO_(2)mixed oxides are considered as one of the key components in the three-way catalysts for automotive exhaust purification.The increasingly strict emission regulations have brought much higher requitements regarding the thermal stability of CeO_(2)-ZrO_(2)mixed oxides.In this work,CeO_(2)-ZrO_(2)with excellent thermal stability were synthesized through co-precipitation method.The effect of synthesizing parameters including doping element,precursors,washing methods as well as ageing conditions on the specific surface area and thermal stability of the CeO_(2)-ZrO_(2)samples were investigated.Results shown that CeO_(2)/ZrO_(2)/La_(2)O_(3)/Y_(2)O_(3)/Nd_(2)O_(3)(CZLYN)samples prepared by using La-Y-Nd co-doping as the modified component,Ce(NH_(4))_(2)(NO_(3))_(6)containing Ce^(4+)as the cerium precursor,washed with ethanol and aged in an ethanol environment for 12 h exhibited the optimal specific surface area and thermal stability.The specific surface can still maintain at 38 m^(2)·g^(-1)after 12 h thermal ageing at 1050℃using muffle furnace.The optimized CZLYN sample was further characterized and compared with one of the commercial CeO_(2)-ZrO_(2)powder.Results showed that these two samples presented similar physical structure,grain size,pore size distribution and surface micro-morphology while the specific surface area of the optimized CZLYN sample was increased by about 60%.After thermal ageing at 1050℃using muffle furnace,the optimized CZLYN sample presented about 20%increase in the specific surface area of compared to the commercial CeO_(2)-ZrO_(2)powder;after hydrothermal ageing,the optimized CZLYN samples still showed slightly higher specific surface area and about 30%increase in dynamic ox oxygen storage/release capacity,indicating its superior thermal stability.

关 键 词：催化剂工程 铈锆复合氧化物 共沉淀法 比表面积 热稳定性 储放氧性能 

分 类 号：TQ426.6[化学工程] O643.36[理学—物理化学]