钙钛矿型稀土复合氧化物超细粒子对CO还原SO_2的催化性能

THE CATALYTIC REDUCTION OF SO_2 BY CO OVER ULTRAFINEPARTICLES WITH PEROVSKITE STRUCTRUE

以共沉淀—超临界干燥法制得了钙钛矿型ＬａＣｏＯ３和ＬａＭｎＯ３稀土复合氧化物超细粒子，测试了该超细粒子对ＣＯ还原ＳＯ２的催化性能，发现随ＬａＣｏＯ３和ＬａＭｎＯ３颗粒粒径减小和比表面积增大其对ＣＯ还原ＳＯ２的催化活性提高。反应产物主要为单质硫，有微量ＣＯＳ和ＣＳ２生成，其中ＣＯＳ可能是ＣＯ还原ＳＯ２生成单质硫过程中的中间产物。

LaCoO 3 and LaMnO 3 ultrafine particles with perovskite structrue were made by co precipitation combined with supercritical drying method.The catalytic performance for reduction of SO 2 by CO over the ultrafine particles was investigated.It was shown that with the decrease of the particle size of the ultrafine particles,with the increase of the specific surface area of the ultrafine particles,the catalytic activity incrases.The products of the reaction mainly were S 2 along with small amount (under 5%) of COS and trace CS 2.The produced COS may be the intermediate from SO 2 to S 2,and COS productivity decreased significantly as the conversion of SO 2 exceeds 50%.