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采用溶胶-凝胶法制备了K+掺杂的La1-xKxCoO3系列钙钛矿结构柴油车尾气炭烟氧化催化剂,用XRD,TG-DTA及程序升温反应等技术详细研究了K+掺杂量及焙烧温度对催化剂结构和炭烟燃烧性能的影响,初步探讨了催化剂结构与性能之间的相关性.实验结果表明,以蔗糖为络合剂在600℃下可以得到纯钙钛矿结构的La1-xKxCoO3纳米晶,其中菱方相为LaCoO3系钙钛矿的高温稳定相,升高焙烧温度及增加K+掺杂量都会促进钙钛矿结构由立方相转变为菱方相.K+的掺杂可以降低炭烟的燃烧温度,一定量的K可以提高炭烟的燃烧速率.700℃焙烧的具有菱方相钙钛矿结构的La0.9K0.1CoO3具有最好的催化性能,对炭烟的起燃点和燃尽温度分别为240及387℃,可以通过柴油车自身的排气热量来实现炭烟的催化燃烧过程.
K + doped La1-xKxCoO3 series perovskite diesel exhaust fume catalysts were prepared by sol-gel method. The effects of K + doping amount and calcination temperature were studied in detail by XRD, TG-DTA and temperature programmed reaction. The relationship between the structure and performance of the catalyst was discussed preliminarily.The experimental results show that La1-xKxCoO3 nanocrystals with pure perovskite structure can be obtained at 600 ℃ with sucrose as complexing agent Crystal, in which rhombohedral phase is the high temperature stable phase of LaCoO3 perovskite, increasing the calcination temperature and increasing the K + doping amount will promote the transformation of the perovskite structure from cubic phase to rhombohedral phase. The doping of K + Of the combustion temperature, a certain amount of K can improve the combustion rate of soot .700 ℃ roasted rhombic phase with perovskite structure La0.9K0.1CoO3 has the best catalytic performance of the soot ignition point and burn-out The temperatures are 240 and 387 ℃, respectively, which can realize the catalytic combustion of soot through the exhaust heat of diesel vehicles.