Enhanced thermal stability of Ce0.33Zr0.55(LaNdY)0.12O2 mixed oxides prepared by sulfate-aided copre

来源 :稀土学报(英文版) | 被引量 : 0次 | 上传用户:wangcx1987
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Ceria-zirconia based mixed oxides (CZs) have been applied in three-way catalysts (TWCs) for their high surface area and oxygen storage capacity (OSC). In this work, enhanced thermal stability of Ce0.33Zr0.55(LaNdY)0.12O2 mixed oxides was realized via a facile and scalable approach, namely, sulfate-aided coprecipitation method was labelled as CZ-S. Sulfate ion (SO2-4 ) was added into raw solution in the form of sulfuric acid and acted as coordination agent. The control sample was prepared by con-ventional coprecipitation method without sulfuric acid added and labelled as CZ. The promotion effect of sulfate ion was analyzed systematically by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), N2 adsorption-desorption, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), OSC and hydrogen temperature-programmed reduction (H2-TPR) analysis. XRD and high resolution TEM results reveal that CZ-S have homogeneous distributions of elements. TEM and SEM images show that fresh samples of CZ-S have narrower distributions of grain sizes and larger pore sizes than those of CZ. Through cross analysis of structure and morphology of CZ and CZ-S, we find that the introduction of sulfate ions results in uniform distributions of elements, narrows distributions of grain sizes, and enables the formation of secondary loose packing of sub-particles, which lead to enhanced thermal stability of the samples of CZ-S upon aging process at high temperature. After aging treatment at 1100 ℃ for 10 h, aged samples of CZ-S present larger specific surface areas and pore volumes than the aged sample prepared by conventional coprecipitation method without sulfate ions added. Furthermore, the aged sample of CZ-S2 (SO2-4 /Zr=1) possesses the highest specific surface area of 21.9 m2/g and the biggest pore volume of 0.035 mL/g among all aged samples.
其他文献
机杼唧唧,丝线缕缕。一卷卷飞速旋转的纱筒,一双双辛勤劳作的双手,一个个尘花飞扬的车间,这就是纺织的世界。在石家庄常山纺织股份有限公司恒盛分公司的车间里有这样一位纺织
在全国新课程理念的指导下,本学期学校高一英语备课组认真学习新理念,探讨并尝试着“引—学—质—练”的课堂教学模式,并把它切实运用到课堂教学中,应用于每个单元的不同课型
Facing the increas ingly complex internat ional petrochemical environment and the country's new and higher requirements for energy development,the Southwest
期刊
In order to inject the safety concept of"pay ten thousands efforts to prevent in case"into the whole process of production,operation and management.Establishing
期刊
随着可持续发展意识的深入,绿色贸易日益盛行且发展成为绿色贸易壁垒,这一趋势对我国的国际贸易产生了极大影响,尤其农业是受影响最为严重的行业之一。解决这一难题的根本途
1.创设语言环境,培养听力习惯。英语教学要为学生营造尽可能多的听说环境,这种环境既包括课内环境,也包括课外环境。比如,教师坚持用英语讲课,使课堂成为一个小小的英语世界,
There are two modes of enterprise innovation: closed innovation and open innovation.rnClosed innovation, just as its name implies means that enterprises carry o
期刊
Before the founding of New China,when exploring the Sichuan Basin,some geologists found a giant paleouplift with a height of about 2000-3000 meters in the long
期刊
The market is the space for the survival and development of enterprises,and the change of the market is the first prerequisite to determine the rise and fall of
期刊
本刊讯(李玉峰赵琬青宋雯琪李嘉伟报道)为全面总结“十三五”期间山东省造纸装备行业取得的显著成就,集中展示优秀企业在这一时期研发的新产品、新技术和取得的新成果,为“十
期刊