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以γ-Al2O3/FeCrAl为基体并提供铝源,采用静态碱络合法制备了镧锰六铝酸盐(LaMn-hexaaluminate,简写LHA)-氧化铝复合涂层LHA-Al2O3。研究了不同沉淀/络合剂(氨水、氢氧化钠、碳酸铵、尿素、乙二胺)对涂层结构、形貌和粘附稳定性能的影响。采用SEM,XRD等对涂层的结构和形貌进行了表征,采用超声波振荡和热冲击对LHAAl2O3/FeCrAl及LHA/LHA-Al2O3/FeCrAl的粘附性能进行了测试,并对催化剂进行了甲烷催化燃烧活性测试。结果表明5个样品的活性结果相近,而氨水样品的粘附性能最好,尿素样品粘附性能最差。说明在保障良好甲烷催化燃烧的前提下,过渡层中嵌入和覆盖的板状LHA颗粒决定了催化剂体系的粘附稳定性。
The lanthanum manganese hexaaluminate (LHA) -aluminum oxide composite coating LHA-Al2O3 was prepared by the method of static alkalisation using γ-Al2O3 / FeCrAl as matrix and aluminum source. The effects of different precipitation / complexing agents (ammonia, sodium hydroxide, ammonium carbonate, urea and ethylenediamine) on the structure, morphology and adhesion stability of the coatings were investigated. The structure and morphology of the coatings were characterized by SEM and XRD. The adhesion of LHAAl2O3 / FeCrAl and LHA / LHA-Al2O3 / FeCrAl was tested by ultrasonic vibration and thermal shock. The catalysts were also catalyzed by methane Burning activity test. The results show that the five samples have similar activity results, while the ammonia sample has the best adhesion performance and the urea sample has the worst adhesion performance. This indicates that the plate-like LHA particles embedded and covered in the transitional layer determine the adhesion stability of the catalyst system under the premise of ensuring good methane catalytic combustion.