摘要
综述了汽车尾气污染的危害，介绍了天然气汽车尾气的特点，及与汽油、柴油车的区别。用共沉淀法制备了铈锆镧铝复合材料，并对其进行了比表面及储氧量的表征，讨论镧的添加量与复合材料织构性能的关系。在铈锆铝中添加La2O3，可以提高其织构性能，同时随La20，添加量的不同，材料的织构性能表现出较大的差异。以此系列复合材料为载体，采用浸渍法制备了单Pd天然气汽车尾气净化催化剂，进行了比表面和储氧量的表征，并对催化剂用于模拟天然气汽车尾气净化进行了初步的活性评价，讨论对比了各催化剂的相关织构特点和活性特点。结果表明，以此系列复合材料作载体制备的天然气汽车催化剂对CH4、CO、NOx均具有良好的起燃活性。说明本论文中镧改性的铈锆铝复合材料具有优良的织构性能和储氧性能，能够满足优良性能天然气汽车尾气催化剂载体的要求，所制备的催化剂初步表现出满足催化净化要求的性能。
Harms of automotive exhausts was summarized. Differences between CNG vehicle exhausts and that of gasoline or diesel oil automobiles were introduced. Composite materials of La- CeO2- ZrO2 -Al2O3 were prepared by co-precipitation. The materials＇ specific sur- face area and oxygen storage capacity were measured. Relationships of additional amounts .of lanthanum oxide and structure properties of the composite materials were discussed. Structure and texture of CeO2 - ZrO2 - A1203 were enhanced when La203 was added. The amount of La203 additive affects the structure and texture of CeO2 - ZrO2 - A120~a lot. Single Pd catalyst supported on the composite materials was prepared by im- pregnation method, specific surface area and oxygen storage capacity of which were measured. Primary evaluation of activities of catalysts was performed under simulation conditon of CNG exhaust gas. Properties of structure, texture and activities of each catalyst was discussed and con- trasted. The results indicate that CNG catalysts supported on this series of composite materials of CeO2 - ZrO2 - Al^O3modified by La203all have good light-off activities. This phenomenon shows that composite materials of CeO2 - ZrO2 -Al2O3 modified by La2O3 have proper structure, texture and oxygen storage capacity which can meet the requirement of excellent support materials applied on CNG catalysts with good performance.
出处
《中国化工贸易》
2012年第10期131-132,共2页
CHINA CHEMICAL TRADE
关键词
铈锆铝复合材料
起燃温度
完全转化温度
三效催化剂
钯
天然气汽车尾气催化净化
composite materials of La -CeO2 -ZrO2 - Al2O3 light-off temperature three-way catalyst palladium emission control in natural gas automobiles
