【摘要】 用溶胶-凝胶法制备一系列不同取值的多元复合铁基钙钛矿化合物.在模拟条件下,以起燃温度和气体转化效率90%时的温度为评价指标测定HC、CO及NOx的三效催化活性.结果表明:改性催化剂具有更高的催化活性和抗老化能力;一定取代量的非贵金属引入可较大幅度提高催化活性,且催化活性与掺杂少量贵金属Ru离子的相似,可能是多元调变使B位离子的变价能力提高,同时使表面氧脱附能力增强的结果.因结构中有氧缺陷结构的催化活性中心SrFeO2.83,SrFeO3-λ晶相存在,La0.6Ce0.2Sr0.2Fe0.4Co0.2Cu0.2Mn0.2O3样品的三效催化性能较佳,起燃温度分别可达到CO 360℃,NOx380℃,HC 520℃.更多还原

【Abstract】 A series multi-component iron-based non-noble perovskite-type compounds are prepared by the sol-gel method.Under simulated exhaust conditions,the catalytic activity is evaluated by using the light-off temperature(the temperature of 50% conversion simplified as T₅₀) and the temperature of 90% conversion(T₉₀) for the three pollutants CO、HC and NO_x.It is found that modified catalyst had higher activities and better aged-resistance.The catalytic activity is greatly improved with a certain amount of non-noble metal doping into catalyst and has better activity similar to doping compound with small amount of Ru.That maybe contribute to the improving capability of B element and the strong absorbency of surface oxygen.Since there exit defect oxgen as the catalytic center in SrFeO_2.83and SrFeO_3-λ,the La_0.6Ce_0.2Sr_0.2Fe_0.4Co_0.2Cu_0.2Mn_0.2O₃ has better activity and T₅₀ of it attain to CO 360 ℃,NO_x380 ℃,HC 520 ℃.更多还原