K-Ce0.5Zr0.5O2催化碳颗粒物燃烧性能

用等体积浸渍法制备了不同K负载量的xKNO₃-Ce_0.5Zr_0.5O₂系列催化剂，用程序升温氧化反应(TPO)考察催化剂对碳颗粒物(soot)燃烧的催化活性. 并采用XRD、BET、FT-IR、XPS等技术对KNO3负载催化剂进行表征. 结果表明KNO₃负载量对催化剂的比表面、表面化学环境有显著的影响；KNO₃能使催化剂对soot的催化燃烧活性有较大提高，且存在最佳负载量，当x=0.5时，催化剂的活性最好，碳颗粒物的起燃温度（Ti）和峰顶温度（Tp）分别为290 ℃和360 ℃. 在反应过程中，KNO₃熔融状态的形成和K₂CO₃的生成，使催化活性明显提高.

Catalytic Performance of K-Ce0.5Zr0.5O2 Catalysts for Soot Combustion

xKNO₃-Ce_0.5Zr_0.5O₂ catalysts were prepared by incipient-wetness impregnation method, and the catalytic activities for the soot combustion were studied using TPO. XRD, BET, FT-IR and XPS were used to investigate the influences of KNO₃ concentration on the catalytic activities for soot combustion. It was found that the KNO3 had great effect on the surface area and the chemical environment. Compare with Ce_0.5Zr_0.5O₂, the catalytic activities of xKNO₃-Ce0.5Zr0.5O2 for soot combustion were improved significantly; the catalyst with x=0.5 had the best catalytic performance, on which Ti and Tp were 290 ℃ and 360 ℃, respectively. The results suggested that the formation of K₂CO₃ and molten KNO₃ phase during the reaction course promoted the catalytic activities obviously.