【摘要】 采用柠檬酸法制备了LaMnO3、LaFeO3、La0.5Sr0.5MnO3、La0.5Sr0.5FeO3,通过负载纳米Pt合成了Pt负载钙钛石催化剂,XRD与IR数据表明合成的催化剂具有钙钛石相,TEM数据表明合成的纳米Pt粒径为~3nm,均匀分散在钙钛石上。在CO氧化反应中,发现钙钛石的氧化-还原性能是影响其活性的重要因素,因而,Mn系钙钛石表现出较高的CO氧化活性。负载纳米Pt后,Fe系钙钛石则显示出更优异的CO氧化活性,CO完全转化的温度从350℃降至120℃。吸附实验表明钙钛石上氧空位对促进O2的吸附起着非常重要的作用,也是影响CO低温氧化的重要因素之一。更多还原

【Abstract】 LaMnO3, LaFeO3, La0.5Sr0.5MnO3, La0.5Sr0.5FeO3 were prepared by citric acid method and Pt/La Mn O3, Pt/La Fe O3, Pt/La0.5Sr0.5Mn O3, Pt/La0.5Sr0.5Fe O3 were prepared by impregnating nano-Pt solution to ABO3 mixed oxides.It showed that prepared ABO3 mixed oxides possessed pervoskite structrue from XRD and IR data,the size of nano-Pt particle was about ~3 nm and dispersed uniformly on ABO3 mixed oxides from TEM. It was found that the redox properties determined the catalytic properties of ABO3-type catalsysts in CO catalytic oxidation, thus,Mn-ABO3 catalsysts gave the better activity in CO catalytic oxidation. When supported nano-Pt paricle to ABO3-mixed oxides, Pt/Fe-ABO3 catalsysts showed the excellent activity, the reaction temperature of 100% CO conversion was reduced from 350 ℃ to 120 ℃. Adsorption experiment indicated that oxygen vacancy on ABO3 mixed oxides was a key factor to improve the adsorption of oxygen and to determine the properties of CO oxidation at lower reaction temperatures.更多还原