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采用浸渍法制备了Pt/Ce0.6Zr0.4O_2粉末催化剂,涂覆到蜂窝陶瓷载体表面得到整体式催化剂。考察了Pt含量及焙烧温度对催化剂在水汽-CO_2环境下催化CO氧化性能的影响,并用XRD,TEM和H2-TPR等手段对载体和催化剂进行了表征。结果表明,在空速50000 h-1的反应条件下,当焙烧温度为300℃时,3.0Pt/Ce0.6Zr0.4O_2整体式催化剂的CO氧化活性最高,反应温度200℃时,CO转化率为87%,具有较高的水汽-CO_2环境下的CO氧化活性。通过对2.0Pt/Ce0.6Zr0.4O_2催化剂在无水汽,无CO_2,无水汽-CO_2及水汽-CO_2环境下的对比实验,发现水汽和CO_2对催化剂的活性有明显的抑制作用,水汽的影响比CO_2的影响要更大一些。这说明水汽、CO_2和CO对催化剂存在竞争吸附。结合催化剂的H2-TPR表征结果,发现催化剂的还原能力越高,相对应的CO氧化活性也越高。添加适量的Pt有利于提高催化剂的还原能力,从而提高其活性,但是过量的Pt会使催化剂活性下降。
Pt / Ce0.6Zr0.4O_2 powder catalyst was prepared by impregnation method and coated onto the surface of honeycomb ceramic carrier to obtain a monolithic catalyst. The effect of Pt content and calcination temperature on the catalytic CO oxidation performance in water-CO 2 environment was investigated. The catalysts and catalysts were characterized by XRD, TEM and H2-TPR. The results showed that under the reaction conditions of airspeed of 50000 h-1, the CO oxidation activity of 3.0Pt / Ce0.6Zr0.4O_2 monolith catalyst was the highest when the calcination temperature was 300 ℃. When the reaction temperature was 200 ℃, the CO conversion was 87%, with higher water vapor-CO 2 environment CO oxidation activity. Through the comparative experiments of 2.0Pt / Ce0.6Zr0.4O_2 catalyst under the condition of no steam, no CO_2, no water vapor-CO 2 and water vapor-CO 2, it was found that water vapor and CO 2 had a significant inhibitory effect on the activity of the catalyst. The influence ratio of water vapor The impact of CO_2 is greater. This shows that water vapor, CO 2 and CO on the catalyst competitive adsorption. Combined with the H2-TPR characterization of the catalyst, it was found that the higher the reducibility of the catalyst, the higher the corresponding CO oxidation activity. Addition of appropriate amount of Pt helps to improve the reduction ability of the catalyst to increase its activity, but excessive Pt can reduce the activity of the catalyst.