【摘要】 以SiC为载体、Pd为活性组分、CeZr为助剂,采用浸渍法制备了Pd-CeZr/SiC催化剂,将其用于CO和C3H6的催化氧化反应,考察了浸渍方式、预还原温度和助剂添加量等因素对催化剂活性的影响,并对催化剂进行了XRD、CO化学吸附和H2-TPR表征。实验结果表明,采用共浸渍方式添加CeZr制备的催化剂活性较高,CeZr的添加提高了Pd在催化剂表面的分散度;其中Pd负载量为0.5%(w)、CeZr添加量为2%(w)的Pd-CeZr/SiC催化剂经250℃预还原处理后具有较高的活性,对CO和C3H6的最低完全转化温度分别为195,200℃,比未添加助剂的Pd/SiC催化剂分别降低了约35℃。更多还原

【Abstract】 Pd-CeZr/SiC catalysts with SiC as the support,Pd as the active content and cerium and zirconium as cocatalysts were prepared by an impregnation method and characterized by means of XRD,CO chemisorption and H2-TPR. The effects of impregnation modes,pre-reduction temperature and cocatalyst dosages on the catalyst performances in the catalytic oxidations of CO and C3H6 were investigated. The results showed that the catalysts synthesized by co-impregnation mode were more active in the catalytic oxidations than other modes,and the dispersion of palladium on the SiC support could be increased by the addition of cerium and zirconium. The catalyst with 0.5%(w) palladium and 2%(w) cerium-zirconium had the high catalytic activity when it was pre-reduced at 250 ℃. The lowest temperatures for the complete conversion of CO and C3H6 on the catalyst were 195 ℃ and 200 ℃,which was 35 ℃ lower than those on Pd/SiC catalyst,respectively.更多还原