化工学报 ›› 2016, Vol. 67 ›› Issue (11): 4742-4749.DOI: 10.11949/j.issn.0438-1157.20160286

• 表面与界面工程 • 上一篇    下一篇

涂覆液种类对FeCrAl金属载体上氧化铝涂层性质的影响

张志飞, 周静红, 叶光华, 周兴贵   

  1. 华东理工大学化学工程联合国家重点实验室, 上海 200237
  • 收稿日期:2016-03-09 修回日期:2016-07-11 出版日期:2016-11-05 发布日期:2016-11-05
  • 通讯作者: 周静红,jhzhou@ecust.edu.cn
  • 基金资助:

    国家重点基础研究发展计划项目 (2014CB239702);国家自然科学基金项目(91434117)。

Influence of coating solutions on properties of γ-Al2O3 washcoat over FeCrAl substrate

ZHANG Zhifei, ZHOU Jinghong, YE Guanghua, ZHOU Xinggui   

  1. State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
  • Received:2016-03-09 Revised:2016-07-11 Online:2016-11-05 Published:2016-11-05
  • Supported by:

    supported by the National Basic Research Program of China (2014CB239702) and the National Natural Science Foundation of China (91434117).

摘要:

利用浸渍提拉法(dip-coating),分别采用铝溶胶与氧化铝浆液在FeCrAl金属载体上制备了两种γ-Al2O3活性涂层,考察了涂覆液种类对涂层性质的影响。利用扫描电镜、X射线衍射、氮气物理吸附和超声波振动方法考察了两种涂层的表观形貌、晶型结构、织构性质及涂层与金属载体之间的结合力。研究结果表明,当涂层负载量小于3%(质量分数,下同)时,溶胶涂层可以避免开裂,而浆液涂层无法避免开裂发生;当负载量大于8%时,溶胶涂层在干燥后会开裂翘起甚至直接脱落,而浆液涂层虽然开裂加剧但是不会直接脱落。对于涂层厚度需求较低的体系(涂层负载量小于8%),溶胶涂层的比表面积和孔容比浆液涂层更大,更适合作为催化剂活性载体;而对于涂层厚度需求较高的体系(涂层负载量大于8%),则应选择浆液涂层。

关键词: 整体器件, 催化剂载体, 溶胶-凝胶, 浆液, 氧化铝涂层, 结合力

Abstract:

Two γ-Al2O3 washcoats on FeCrAl substrate were prepared by dip-coating boehmite sol gel or γ-Al2O3 slurry. The effects of coating solution on the washcoat properties were extensively studied. The washcoat morphology, crystal structure, texture and adhesion to substrate were investigated by SEM, XRD, nitrogen physic sorption and ultrasonic vibration. At coating loading less than 3%(mass), boehmite washcoats were crack-free but γ-Al2O3 washcoats were crack-rich. At coating loading above 8%(mass), boehmite washcoats developed crack, flake and delamination whereas γ-Al2O3 washcoats developed only crackings without delamination. In case of requirement for relatively low coating loading (<8%), boehmite washcoats were more suitable as carrier for monolithic catalysts due to higher specific surface area and pore volume than γ-Al2O3 washcoats. γ-Al2O3 washcoats were preferred as catalyst carrier if higher coating loading was needed (>8%).

Key words: monolith, catalyst support, sol-gel, slurry, alumina washcoat, adhesion

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