【作者】 罗勇悦；

【导师】 龚茂初；

【作者基本信息】 四川大学 ， 工业催化， 2004， 硕士

【摘要】 以γ-Al2O3、储氧材料(OSM)、Y2O3,ZrO2来稳定的γ-Al2O3(YSZ-Al2O3)及YSZ-Al2O3+OSM等为载体,以Co3O4为主要活性组分,Fe2O3和MnO2为助剂,堇青石蜂窝陶瓷为基体制备了整体式甲烷燃烧催化剂。利用连续流动微型反应装置研究了催化剂的反应性能,抗老化性能及反应条件对反应性能的影响。用XPS、XRD,TPR,BET等对催化剂进行表征。结果表明:1000℃处理后的催化剂,Co3O4/γ-Al2O3严重失活、Co3O4/ YSZ-Al2O3、Co3O4/ YSZ-Al2O3+OSM几乎不失活。XPS、XRD结果显示Co3O4/γ-Al2O3失活的原因是生成了对甲烷催化燃烧没有活性的尖晶石型的CoAl2O4,载体γ-Al2O3发生了向α-Al2O3的转变;Co3O4/ YSZ-Al2O3、Co3O4/ YSZ-Al2O3+OSM则没发现尖晶石型的CoAl2O4生成,载体也没有发生向α-Al2O3的相变。用YSZ-Al2O3和YSZ-Al2O3+OSM为载体的8wt.%Co3O4甲烷燃烧催化剂,老化后保持较大的比表面,分别为112.3m2/g和100.2m2/g,;单独用储氧材料为载体的甲烷催化燃烧催化剂,老化后比表面只有8.5m2/g。不同Co3O4含量的单组分Co基催化剂,经老化后,以8wt.%Co3O4/YSZ-Al2O3+OSM(C3)的活性和稳定性最好。二组分催化剂Co3O4+Fe2O3/YSZ-Al2O3+OSM和三组分催化剂Co3O4+Fe2O3+MnO2/YSZ-Al2O3+OSM比单组分Co基催化剂有更好的催化活性和热稳定性,尤其是三组分催化剂Co3O4+Fe2O3+MnO2/YSZ-Al2O3+OSM(B1)的性能最佳。将三组分催化剂Co3O4+Fe2O3+MnO2/YSZ-Al2O3+OSM用在催化燃气炉上,能使热效率达到67%,污染物排放量和噪声远远低于传统燃烧器,具有高效率节能和环境友好的双重优点。更多还原

【Abstract】 A series of cobalt-based catalysts had been prepared with supports γ-Al2O3, OSM(oxygen storage materials,CeO2-Y2O3- ZrO2), YSZ-Al2O3(γ- Al2O3 modified by Y2O3 and ZrO2) and mixed YSZ-Al2O3+OSM using impregnation method and were coated on the surface of cordierite. The catalytic activities and ageing resistant performance of above catalysts for methane combustion was evaluated in a continuous-flow micro-reactor. They were also characterized by XRD, XPS, BET and H2-TPR.The results showed that after aging at 1000℃, Co3O4/γ-Al2O3 almost lost its activity, but Co3O4/ YSZ-Al2O3, Co3O4/ YSZ-Al2O3+OSM could still remained its activities. The results of XRD, XPS showed that the reason of low activity of Co3O4/γ-Al2O3 to α-Al2O3 was the formation of crystal of CoAl2O4 and transformation of γ-Al2O3. While there were almost no CoAl2O4 formation and transformationα-Al2O3 in the catalysts of Co3O4/ YSZ-Al2O3, Co3O4/ YSZ-Al2O3+OSM. Both fresh and aged Co3O4/ YSZ-Al2O3 and Co3O4/ YSZ-Al2O3+OSM remain high specific surface area .While for Co3O4/ OSM specific surface area is only 8.5m2/g after aged 1000℃. Among Co3O4/ YSZ-Al2O3+OSM with different Co3O4 loading , 8 wt.% Co3O4/ YSZ-Al2O3+OSM is most active and stable. Both Co3O4+Fe2O3/YSZ-Al2O3+OSM and Co3O4+Fe2O3+MnO2/YSZ-Al2O3+OSM are active and stable. But Co3O4+Fe2O3+MnO2/YSZ-Al2O3+OSM exhibits the highest activity and stability. The combustion stove equipped with Co3O4+Fe2O3+ MnO2/YSZ- Al2O3+OSM catalyst <WP=4>had high thermal efficiency and low pollution emitting.更多还原