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在反相微乳液中以碳酸铵共沉淀法制备了LaMnAl11O19α甲烷燃烧催化剂,比较了反相微乳液法与普通碳酸铵共沉淀法对催化剂相结构、比表面积、孔结构及其催化甲烷燃烧性能的影响.结果表明,反相微乳液法制备的催化剂前驱体平均粒径为2.3nm,而普通碳酸铵共沉淀法得到的催化剂前驱体平均粒径为30.1nm.在乙醇超临界干燥阶段,反相微乳液法制备的催化剂前驱体较容易发生铝羟基分子间脱水,形成较为丰富的孔,保持了各组分分布的均匀性,从而促进了六铝酸盐的形成,所得样品具有较大的比表面积和较高的催化甲烷燃烧的活性.
The LaMnAl11O19α methane combustion catalyst was prepared by coprecipitation with ammonium carbonate in reverse microemulsion. The phase structure, specific surface area, pore structure and catalytic activity of methane combustion were compared between the reversed microemulsion method and ordinary ammonium carbonate coprecipitation method .The results showed that the average particle size of catalyst precursor prepared by reverse microemulsion method was 2.3nm, while the average particle size of catalyst precursor obtained by common ammonium carbonate coprecipitation method was 30.1nm.In the supercritical drying stage of ethanol, The catalyst precursors prepared by the microemulsion method are more prone to dehydration between the aluminum and the hydroxyl molecules to form more abundant pores and maintain the uniformity of the distribution of the components, thereby promoting the formation of the hexaaluminate. The resulting sample has a larger ratio Surface area and high catalytic activity of methane combustion.