La_(0.9)Mg_(0.1)Cr_(1-x)M_xO_3钙钛矿型氧化物的制备及催化性能研究

Preparation and Three-Way Catalytic Performance of La_(0.9)Mg_(0.1)Cr_(1-x)M_xO_3 Peroviskite-Type Mixed Oxides

采用溶胶-凝胶法制备一系列钙钛矿复合氧化物La0.9Mg0.1Cr1-xMxO3(M为Fe、Cu和Ni),并考察其催化性能.同时利用扫描电子显微镜和X射线衍射等分析方法,表征催化剂性能与结构之间的关系.实验结果表明:750℃焙烧制得的La0.9Mg0.1Cr0.8Cu0.2O3具有良好的三效催化性能,在该催化剂上C3H6、CO和NO的起燃温度T50较低,分别为229℃、202℃和286℃;完全转化温度T90分别为325℃、247℃和348℃;500℃转化率分别高达91.1%、99.3%和93.9%.La0.9Mg0.1Cr0.8Cu0.2O3具有良好的钙钛矿晶体结构,晶粒为纳米级,热稳定性高,所以催化性能良好.

A series of La0.9Mg0.1Cr1-xMxO3（M = Fe, Cu,Ni ）perovskite-type mixed oxides were synthesized using sol-gel method and the performance of catalysts was also investigated. The relationship between the catalytic activity and the structure of catalyst was explored by using the X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The results showed that the La0.9Mg0.1Cr1-xMxO3 catalyst exhibited high three-way catalytic performance when it was calcined at 750 ℃. Under the function of the catalyst, the Tso of C3H6, CO and NO were 229 ℃, 202 ℃ and 286 ℃; the T9o of C3H6, CO and NO were 325℃, 247℃ and 348 ℃; the conversion efficiency of C3H6, CO and NO were 91.1%, 99.3% and 93.9% respectively at 500 ℃. The La0.9Mg0.1Cr1-xMxO3 catalyst had good perovskite-type crystal structure and its grain was nanocrystal, and it showed excellent thermal stabilities and good catalytic property.