As catalytic materials, nanometer rare earth perovskites LaMnO3 were prepared by NaOH-Na2CO3 coprecipitation, followed by supercritical drying, vacuum drying and air drying respectively. The effect of drying processes...As catalytic materials, nanometer rare earth perovskites LaMnO3 were prepared by NaOH-Na2CO3 coprecipitation, followed by supercritical drying, vacuum drying and air drying respectively. The effect of drying processes was studied on the catalyst performance through XRD, TEM, SEM and BET analysis. The results demonstrated that about 30 nm LaMnO3 particles could be prepared by three drying processes respectively. The catalyst materials LaMnO3 dried in vacuum presented the largest specific surface area as 28.71 m2·g－ 1. Compared to the catalyst prepared by dipping cordierite directly in the salt solutions, nanometer LaMnO3 showed better catalytic activity. The light-off temperatures for CO and HC oxidation were both lowered by 100℃ , and its NOx conversion could be up to 100％ at 570℃ .展开更多
CeO2-ZrO2复合氧化物具有良好的储放氧性能(Oxygen Storage Capacity,OSC),可以有效地调节尾气空燃比、拓展催化剂的工作温度窗口,是汽车尾气三效催化剂(Three Way Catalysts,TWC)中的关键材料之一。随着环保要求的不断提高和相关排放...CeO2-ZrO2复合氧化物具有良好的储放氧性能(Oxygen Storage Capacity,OSC),可以有效地调节尾气空燃比、拓展催化剂的工作温度窗口,是汽车尾气三效催化剂(Three Way Catalysts,TWC)中的关键材料之一。随着环保要求的不断提高和相关排放法规的日益严格,对铈锆复合氧化物的热稳定性、低温还原性能和储放氧能力提出了更高的要求。简述了包括共沉淀法、溶胶-凝胶法、高能球磨法、模板法在内的铈锆复合氧化物常用合成方法,阐述了铈锆复合氧化物的基本改性机制,综述了常见的碱土元素以及过渡金属对铈锆复合氧化物的改性效果及原理,介绍了我国铈锆复合氧化物的市场需求、国内外主要铈锆生产厂家的生产技术及其主要产品性能、我国铈锆复合氧化物的产业化现状及进展。最后,从研究应用和产业化发展两个方面进行了展望。展开更多
文摘As catalytic materials, nanometer rare earth perovskites LaMnO3 were prepared by NaOH-Na2CO3 coprecipitation, followed by supercritical drying, vacuum drying and air drying respectively. The effect of drying processes was studied on the catalyst performance through XRD, TEM, SEM and BET analysis. The results demonstrated that about 30 nm LaMnO3 particles could be prepared by three drying processes respectively. The catalyst materials LaMnO3 dried in vacuum presented the largest specific surface area as 28.71 m2·g－ 1. Compared to the catalyst prepared by dipping cordierite directly in the salt solutions, nanometer LaMnO3 showed better catalytic activity. The light-off temperatures for CO and HC oxidation were both lowered by 100℃ , and its NOx conversion could be up to 100％ at 570℃ .
文摘CeO2-ZrO2复合氧化物具有良好的储放氧性能(Oxygen Storage Capacity,OSC),可以有效地调节尾气空燃比、拓展催化剂的工作温度窗口,是汽车尾气三效催化剂(Three Way Catalysts,TWC)中的关键材料之一。随着环保要求的不断提高和相关排放法规的日益严格,对铈锆复合氧化物的热稳定性、低温还原性能和储放氧能力提出了更高的要求。简述了包括共沉淀法、溶胶-凝胶法、高能球磨法、模板法在内的铈锆复合氧化物常用合成方法,阐述了铈锆复合氧化物的基本改性机制,综述了常见的碱土元素以及过渡金属对铈锆复合氧化物的改性效果及原理,介绍了我国铈锆复合氧化物的市场需求、国内外主要铈锆生产厂家的生产技术及其主要产品性能、我国铈锆复合氧化物的产业化现状及进展。最后,从研究应用和产业化发展两个方面进行了展望。
