【摘要】 高标准排放法规要求汽车尾气净化催化剂在冷启动阶段对碳氢化合物（HC）进行吸附存储,在正常工作温度下脱附并催化净化。汽油车尾气中的HC主要成分为甲苯,因此选用了NaY、USY和ZSM-5分子筛,制备了CeO₂改性的不同分子筛材料;利用比表面分析仪（BET）、高分辨透射电子显微镜（HRTEM）、热重分析仪（TG）、化学吸附仪和X射线衍射分析仪（XRD）,表征分析了不同分子筛以及CeO₂改性后结构与酸碱性的变化对甲苯的吸附与脱附性能。结果表明,未改性前,USY分子筛对甲苯的吸附性能最佳,甲苯的饱和吸附量达到245.9mg/g,甲苯的脱附温度范围为290～360℃;CeO₂改性后分子筛的吸附量均有明显的提升,其中CeO₂/USY材料对甲苯的吸附量最佳,达到270mg/g,比未改性USY的提升了约10%。更多还原

【Abstract】 High standard emission regulations require that vehicle exhaust gas purification catalyst adsorbs and stores hydrocarbons（HC）during vehicle cold start stage,and then desorbs and purifies them at normal operating temperature.Toluene is main component of HC in tail gas of gasoline vehicles.Therefore,NaY,USY and ZSM-5 molecular sieves were selected to prepare different molecular sieve materials modified by CeO₂.Adsorption and desorption properties of toluene were characterized and analyzed by N₂ physical adsorption instrument,high resolution transmission electron microscope（TEM）,chemical adsorption instrument and X-ray diffraction（XRD）instrument.The results show that adsorption capacity of USY zeolite to toluene is the best before modification,saturated adsorption capacity of toluene is 245.9 mg/g,and toluene desorption temperature range is 290—360 ℃ .Adsorption capacity of molecular sieve is significantly improved after CeO₂ modification,among which CeO₂/USY material has a best adsorption capacity for toluene,reaching to 270 mg/g,which is about 10% higher than that of unmodified USY.更多还原