金属丝网蜂窝催化剂的制备及应用

【英文摘要】 Wire-mesh honeycomb (WMH) is a category of novel monolithic catalysts supported on structured wire-mesh substrate. As the conduct of WMH is made of mesh, whose pores provide fluids the bypass of radical mixing across the bed diameter, which effect can improve the fluid distribution and mixing state, thus raises transfer efficiency. Aimed at developing a WMH for general applications, this thesis tried to breakthrough the key difficulties in WMH preparation. For purpose of demonstration, the WMH washcoated by Pd/Al2O3 was prepared and applied in catalytic combustion of air diluted methane, with its result compared to the ceramic counterpart.The key problem in developing WHM is the fast adhesion of the active catalyst powder with the metallic mesh. To solve this problem, an aluminum/alumina coating was prepared by electrophoretic deposition (EPD) on top of wire-mesh surface. Experiments were carried out to find the optimal conditions in ethanol, butanone and acetone suspension for depositing a uniform Al particulate coating, which are concluded as below: in ethanol suspension, PVP: 0.2 wt.%, AlCl3: 2.5 mM, Al powder: 1wt.%, electric field intensity: 30 V/cm, deposition time: 10min; in butanone suspension, nitrocellulose: 0.6 wt.%, n-butylamine: 10 vol.%, Al powder: 0.2 wt.%, electrical field intensity: 50 V/cm, deposition time: 30 min, while in acetone suspension, acetone: 50 mL, nitrocellulose: 0.1 g, Al powder: 1 g, teramethyl ammonium hydroxide: 0.3 mg, phosphoric acid: 0.25 mg, electrical field intensity: 25 V/cm, deposition time: 3 min. Acetone suspension is more stable and the adherence of deposited coatings are higher than ethanol and butanone suspension, and the coating thickness is 50μm. Well adherent and porous aluminum/alumina top layers were prepared by thermal and chemical treatment of the deposited coatings in acetone suspension.After EPD, thermal & chemical treatment, and mould processing, the WMH support was prepared, which was 25 mm in diameter, 21 mm in height, 10 g in weight and 37.1 cm2/g in geometric surface area. The WMH catalyst washcoated with Pb/Al2O3 (Pb wt.% = 0.33%) was tested in catalytic combustion of air diluted methane. Compared at 600℃, CH4 conversion in WMH is 10.89% higher than the catalyst supported on ceramic substrate and the overall reaction rate constant more than doubled.

【中文关键词】 金属丝网蜂窝催化剂; 电泳沉积; 热处理; 化学处理; 甲烷催化燃烧

【英文关键词】 wire-mesh honeycomb catalyst; electrophoretic deposition; thermal treatment; chemical treatment; catalytic combustion of methane

【毕业论文目录】

摘要 4-6

ABSTRACT 6-7 1.1 研究背景 10-11 1.2.1 整体式催化剂组成 11-13 1.2.3 整体式催化剂研究与进展 14-15 1.3 金属载体催化剂涂层制备技术 17-25 1.3.2 电泳沉积法简述 20-25 1.5 本论文主要研究内容 26-28

第二章 电泳沉积法在FeCrAl 合金丝网上制备铝颗粒涂层 28-47 2.1.1 FeCrAl 金属丝网支撑体的预处理 28 2.1.3 乙醇体系中电泳沉积法制备铝颗粒涂层 28-30

2.1.4 丁酮体系中电泳沉积法制备铝颗粒涂层 30

2.1.5 丙酮体系中电泳沉积法制备铝颗粒涂层 30-31

2.2 结果与讨论 31-45 2.2.2 乙醇体系中铝颗粒电泳沉积的结果讨论 32-37

2.2.3 丁酮体系中铝颗粒电泳沉积的结果讨论 37-40

2.2.4 丙酮体系中铝颗粒电泳沉积的结果讨论 40-45

2.3 本章小结 45-47

第三章 铝颗粒涂层的后处理及金属蜂窝载体的成型 47-54

3.1 实验部分 47-49

3.1.1 铝颗粒涂层的热处理 47 3.1.3 FeCrAl 金属丝网蜂窝载体的制备 48-49

3.2 结果与讨论 49-53

3.2.1 铝颗粒涂层的热处理 49-51 3.2.3 FeCrAl 金属丝网蜂窝载体 52-53

3.3 本章小结 53-54

第四章 FeCrAl 金属丝网蜂窝催化剂在甲烷催化燃烧中的应用 54-59

4.1 实验部分 54-55

4.1.1 实验目的 54 4.1.3 实验步骤 55

4.2 结果与讨论 55-58

4.2.1 载体催化活性组分的涂敷 55-56

4.2.2 金属丝网和氧化铝陶瓷催化剂活性及反应速率常数对比 56-58

4.3 本章小结 58-59

第五章 全文总结 59-62

5.1 主要结论 59-61 参考文献 62-66

致谢 66-67

攻读硕士学位期间发表的论文 67-68

上海交通大学学位论文答辩决议书 68