论文总字数：20467字

摘 要

使用三效催化剂对汽车尾气进行催化转化可以大幅度减少汽车尾气污染物的排放。作为三效催化剂的重要载体，铈锆固溶体的研究越来越受到人们的重视。它的性能高低严重影响着催化剂的催化效率。近年来，研究者们将铈锆固溶体和金属氧化物复合制备成了一种新型材料，这种新型材料同时具有铈锆较好的储氧性能和碱土金属氧化物较高的表面积的优点。

本研究以分步沉淀法制备了不同掺铝比例的铈锆固溶体，并利用自动吸附仪，X射线多晶衍射仪、透射电子显微镜等表征仪器对铈锆固溶体的比表面积、物质晶相结构和表面微观形貌等方面进行研究，并用储氧性能对负载催化剂进行了评价。从是否掺铝、不同掺铝比例、不同铝源、不同铈锆比例四个方面探讨了铝的掺杂对铈锆固溶体载体性能的影响。

实验结果表明，铈锆和氧化铝复合材料与纯铈锆固溶体相比，具有更高的比表面积、更好的热稳定性能及储氧性能。当掺杂氧化铝的质量分数在20%~40%之间，所制备的铈锆铝复合氧化物样品焙烧后，仍能保持稳定的立方萤石型结构、较大的比表面积和较好的储氧性能，表明铈锆铝复合氧化物具有良好的热稳定性。

关键词：铈锆固溶体 氧化铝 储氧能力 比表面积

Preparation of high temperature resistant ceria zirconia solid solution

Abstract

Catalytic conversion of vehicle exhaust gas by three-way catalyst can greatly reduces the pollutant emission of automobile. Ceria-zirconia solid solution is an important support used in three-way catalyst, its property significantly affects the performance of the catalyst, thus, research in this field has attracted wide attention across the world. Recently, a new type of material has been developed by scientists via combination of this solid solution and other metal oxides to obtain good oxygen storage capacity and high surface area.

In this study, ceria-zirconia solid solution with various Al doping ratio was prepared via stepwise precipitation. The specific surface area, crystalline phase structure, surface morphology and oxygen storage capacity of this material were characterized by automatic adsorption apparatus, X-ray diffraction (XRD) and transmission electron microscopy (TEM).

The experimental results show that, comparing to pure cerium zirconium solid solution, the composite material of Ceria-Zirconia and alumina has higher specific surface area, better thermal stability and oxygen storage property. With alumina addition in the range of 20%~40%, the composite oxide samples of Ceria-Zirconia and alumina still maintains the stability of the cubic fluorite structure, larger surface area and better oxygen storage capacity after calcination, indicating that Ceria-Zirconia and alumina composite oxides have good thermal stability.

Key words:Ceria-Zirconia solid solution; Alumina;Oxygen storage capacity;Specific surface areas

目录

摘要 I

Abstract II

第一章 前言 1

1.1铈锆固溶体的用途 1

1.2铈锆固溶体的制备方法 2

1.3铈锆固溶体的改性 3

1.4本文研究内容及意义 4

第二章 实验部分 5

2.1试剂及仪器 5

2.2 考察铈锆固溶体样品的影响因素 5

2.3 铈锆固溶体样品的制备 6

2.4 铈锆固溶体样品的表征方法 7

2.4.1 铈锆固溶体样品的比表面（BET）的测定 7

2.4.2 铈锆固溶体样品的XRD表征 7

2.4.3 铈锆固溶体样品的TEM测定 8

2.4.4 铈锆固溶体样品的储氧量（OSC）测定 8

第三章 结果与讨论 9

3.1 掺铝对铈锆固溶体的影响 9

3.1.1 XRD分析 9

3.1.2 TEM分析 11

3.1.3 BET分析 12

3.1.4 OSC分析 12

3.2 掺不同比例的铝对铈锆固溶体的影响 14

3.2.1 XRD分析 14

3.2.2 BET分析 15

3.2.3 OSC分析 15

3.3 不同铝源对铈锆固溶体的影响 16

3.3.1 XRD分析 16

3.3.2 TEM分析 17

3.3.3 BET分析 19

3.4不同铈锆比对铈锆固溶体的影响 19

3.4.1 XRD分析 19

3.4.2 BET分析 20

第四章 结论 22

参考文献 23

致谢 26

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