钙钛矿型稀土催化剂的制备及性能研究+文献综述

摘要：本文优化了溶胶凝胶法，以乙醇为溶剂，加入PEG为分散剂，降低了凝胶形成的时间在降低的温度下焙烧,成功的获得具有纯的钙钛矿型复合氧化物LaCoO3纳米颗粒。在此基础上并对其A(La)位和B(Co)位分别进行了不同元素的掺杂，制得了系列掺杂钙钛矿型复合氧化物，对该系列掺杂氧化物进行XRD检测发现，由于A位离子的掺杂含量较少，掺杂没有改变钴酸镧的ABO3型结构，得到的是系列掺杂钙钛矿型复合氧化物。同时B位离子以Ni掺杂，LaCoxNi1-xO3在x=0.2, 0.3,0.5,0.7范围内，产物的结构并没有改变，仍然是钙钛矿结构。最后，以CO氧化反应为目标反应，不同组成的产物的催化活性，结果表明A位离子的掺杂La0.8M0.2CoO3的催化活性要优于未掺杂的LaCoO3，其中以La0.8Ce0.2CoO3的催化活性最佳。而B位离子Ni的掺杂，设计出LaCoxNi1-xO3催化剂要比A位离子掺杂的La0.8M0.2CoO3的催化活性都要强。
关键词: LaCoO3，溶胶凝胶法，CO氧化，钙钛矿型4833
Preparation and properties of rare earth perovskite-type catalysts
Abstract: This paper optimized the sol-gel method, using ethanol as solvent, PEG as dispersing agent, which can reduces the gel forming time. By using this method, pure perovskite composite oxide LaCoO3 nanoparticles have been successfully obtained. Furthermore, the A (La) and B (Co) sites have been doped by other ions, respectively to form the rare earth catalysts with perovskite phase. Their structures have been chareaterized by X- ray diffraction, which have presented pure perovskite phase. Since the amount of doedions is less, it replacing A sites did not change the LaCoO3 structure. Besides, we have also prepared a series of perovskite-type rare earth compound oxides with the formula of LaCoxNi1-xO3 (x = 0.2, 0.3, 0.5, 0.7) by using Ni to replace Co and found that the as – prepared samples remained the same perosvkite structure. Finally, taking CO oxidation as a target reaction, results showed that the catalytic activity of La0.8M0.2CoO3 doped aions are better than that of the undoped LaCoO3 and the catalytic activity of La0.8M0.2Co03 is the best. While the B ion doped by Ni, the catalytic activity of LaCoxNi1-xO3 catalyst are better than that of A ions doped by M ions.

Key Words: LaCoO3, sol–gel method, Co oxidation, perosvkite type.
目录
1 文献综述   1
1.1 前言   1
1.1.1 CO氧化的研究背景   1
1．2 CO氧化的催化剂   1
1.2.1 非贵金属催化剂   1
1.2.2贵金属催化剂   2
1.3钙钛矿型稀土催化剂的发展状况   2
1.3.1 钙钛矿结构的稀土催化剂   2
1.4稀土钙钛矿催化剂的制备方法   3
1．4．1燃烧合成法   4
1．4．2机械混合法   4
1．4．3共沉淀法   5
1．4．4溶胶-凝胶法   5
1.5本文的选题和研究内容   6
1.5.1本文的选题   6
1.5.2 本文的主要研究内容   6
2 实验部分   7
2.1实验药品和仪器   7
2.1.1实验药品   7
2.1.2实验仪器   8
3 实验步骤   8
3.1 LaCoO3的合成   8
3．1．1工艺流程图   8
3．1．2实验步骤：   9
3.2 La0.8M0.2CoO3的合成   9
3.3 LaCoxNi1-xO3 的合成   9
4 催化剂的表征   10
4.1. X-射线衍射分析(XRD)   10
4.2.扫描电镜分析（SEM）   10
4.3. 低温N2 吸脱附等温线(BET)   10 钙钛矿型稀土催化剂的制备及性能研究+文献综述:http://www.751com.cn/huaxue/lunwen_1621.html