| Automobile exhaust gases pollution has become more and more worse as the automobile industry developing. In order to decrease the pollution by using the rear-earth resource in our country, developing highly active rear-earth catalyst seems very important. Our work put emphases on the relation between physical properties and catalytic activity of perovskite-type rare-earth compound oxides so as to improve catalytic activity of the catalyst. We prepared a series of perovskite-type rare-earth compound oxides with the formula of La0.8Sr0.2Mn1-xCoxO3(x=0,0.1,0.3,0.5,0.7,0.9,1.0) using the method of low temperature combustion sol-gel. This series of oxids have different proportion of element Co in the position B. The sample's catalytic activity was tested using gas chromatography. We have characterized the catalyzers on the structure, size,catalytic surface area, superficial topgraphy and magnetic properties by means of X-ray diffraction(XRD), specific surface area testing (BET), scanning electron microscope(SEM), superconducting quantum interference device(SQUID) etc. we also analyzed the test results in detail. The study showed that the samples'physical properties and catalytic activity have some correlation. The samples'factor t of the structure, specific surface area, and particulate of surface topography have positive correlation with catalytic activity, while samples'specific magnetization have negative correlation with catalytic activity. The samples'catalytic activity increases with the proportion's augment of Co in the position B. The samples'factor t and magnetic properties are dependent on ion B's radius and its electron configuration. And specific surface area depends on not only samples'physical properties but also preparation technique. So as long as we put efforts on choosing ion B and optimizing preparation techniques, we will excogitate perovskite-type rare-earth catalyst with premium quality.
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