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With diesel exhaust pollution is worsening, it becomes urgent to exhaust gas purification . The main purpose of this paper is to synthesize a larger specific surface area and high activity of perovskite oxides, established by laboratory reactor , examine its simultaneous removal of diesel exhaust emissions of soot particles and NOx catalytic activity , automobile exhaust purification catalyst for the new development foundation . Respectively, by co-precipitation method, sol - gel synthesis of perovskite -type oxides LaCoO3 and examine various factors on the perovskite structure and performance. The results showed that coprecipitation of LaCoO3 perovskite oxides , small surface area , during the preparation phase there are other miscellaneous appear ; in various factors, the precipitant concentration and water consumption of the prepared perovskite specific surface area of ??the composite oxide ore affected. The sol - gel method can be perfect crystalline phase perovskite , and it has a larger surface area, where water consumption of the prepared perovskite composite oxide surface area affected. Then , the alkali metal and alkaline earth metal doping of LaCoO3 perovskite composite oxide was modified by FT-IR analysis, the modified perovskite composite oxide of the BO bond strength increases, and BO6 symmetry changes, its symmetry enhancement, in which the sol - gel preparation of the sample of the modified complex oxide BO bond strength and symmetry enhancement BO6 more obvious . Created using a laboratory experimental apparatus for the reaction of the prepared catalyst performance evaluation , the study found , by the co-precipitation method and sol - gel prepared LaCoO3 perovskite composite oxide catalysts were able to significantly reduce the carbon black particles T10, T50, T90, and can greatly improve the selectivity to CO2 , while the conversion of NOx to N2 has a high conversion rate . Which, by the sol - gel prepared La0.9K0.1CoO3 the simultaneous removal of soot emissions from diesel exhaust particulate and NOx when the activity is best , T10 reduces soot particles in 104 ℃, T90 reduces the 210 ℃; and La0.9K0.1CoO3 can significantly promote the conversion of NOx to N2 , N2, nitrogen oxides to the maximum conversion rate of up to 69%.
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