【摘要】 分别用热解硝酸铈法和浸渍法制备了不同物性的CeO2粉体和相应的CuO/CeO2催化剂,并用XRD,HRTEM和TPR等对样品进行了表征,利用微反-色谱装置考察了其催化CO低温氧化的活性.结果表明,热解温度影响CeO2的物性(形貌、粒度大小及分布等).相同条件下,不同物性的CeO2载体上CuO的负载情况不同,500℃热解获得的CeO2载体上非晶态CuO负载量最高,相应的CuO/CeO2催化剂活性也较高.非晶态CuO一部分进入CeO2晶格,另一部分高度分散于CeO2表面上.焙烧温度较低时(≤600℃),催化剂活性受焙烧温度的影响较小,而高温(800℃)焙烧后,催化剂则因载体粒度增大和CuO烧结团聚等因素导致催化活性明显降低.更多还原

【Abstract】 CeO₂ particles with different physical properties were prepared by thermal decomposition of cerous nitrate and then used as supports for CuO/CeO₂ catalysts （CuO content was 6.3% based on the CeO₂ mass） prepared by impregnation method.The CeO₂ particles and CuO/CeO₂ catalysts were comparatively investigated by XRD,HRTEM and TPR measurements.The catalytic properties of the catalysts for low-temperature CO oxidation were studied by using a microreactor-GC system. The results showed that the thermal decomposition temperature affected the physical properties（such as morphology,particle size and distribution） of CeO₂ particles.The loading of non-crystal CuO on the CeO₂ supports was different and it was the highest on the CeO₂ prepared by thermal decomposition at 500 ℃, and the corresponding CuO/CeO₂ catalysts exhibited higher activity for CO oxidation than those with CeO₂ prepared by thermal decomposition at 400 and 700 ℃.A part of non-crystal CuO in CuO/CeO₂ catalysts entered CeO₂ lattice and the others dispersed over the CeO₂ surface.When the calcination temperature was lower than 600 ℃,it had little effect on the catalytic activity.However, high calcination temperature（（e.g.） 800 ℃） resulted in a significant impact on the catalytic activity because of CeO₂ crystal growth and CuO aggregation.更多还原