Pd基无涂层整体式催化剂上甲苯催化燃烧净化研究

Catalytic combustion of toluene on Pd-based monolithic catalyst without coating

  • 摘要:  采用化学镀法在堇青石蜂窝陶瓷基体上制备了Pd基无涂层整体式催化剂Pd/cord,并对其在甲苯催化燃烧净化反应中的催化性能进行了研究。结果表明,Pd/cord催化剂在钯负载量较低(如为0.24%)时,即可使甲苯从201℃起燃后,突跃到226℃完全转化,表现出良好的甲苯催化燃烧净化性能。该类催化剂在空速6000h-1~40000h-1和甲苯进样浓度0.5g/m3~8.0g/m3表现出良好的适用性。105h稳定性实验也表明,Pd/cord催化剂具有很好的催化反应稳定性,甲苯转化率始终保持在97%以上。对该类催化剂进行SEM、XRD和H2-TPR表征,结果表明,仅在钯负载量为0.24%时,Pd/cord催化剂上活性组分PdO颗粒的粒径较小且大小均一,在堇青石基体表面分散均匀,无团聚和多层重叠现象。

     

    Abstract: A new Pd-based monolithic catalyst on cordierite honeycomb ceramics substrate without coating (Pd/cord) was prepared via electroless plating. The results of activity tests for catalytic combustion of toluene showed that Pd/cord catalysts with low Pd loading had good catalytic activities: toluene could light off at 201℃, then leap to 226℃ to burn out on Pd/cord catalyst with 0.24% Pd loading. And Pd/cord catalyst was also suitable for toluene catalytic combustion when space velocities and feed toluene concentrations varied in 6000h-1~40000h-1 and 0.5g/m3 ~8.0g/m3 respectively. During the 105h stability test of Pd/cord catalyst, the toluene conversion was kept above 97%, which indicated that this catalyst possessed good catalytic stability. The scanning electron microscope (SEM), X-ray diffraction (XRD) and temperature programmed reduction in hydrogen (H2-TPR) characterizations showed that the sizes of PdO crystal particles in Pd/cord catalyst when Pd loading was 0.24%, PdO particles were also equably distributed on the surface of cordierite substrate with no overlapping aggregation phenomenon.

     

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