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我们采用柠檬酸配合法制备了Ce基复合氧化物催化剂,分别在热重分析仪(TG)和管式反应器中测试了其氧化碳烟及同时脱除NOx的催化活性;并利用XRD、BET、H2-TPR、XPS表征手段考察其结构.其中,Co0.1/C e La0.05复合氧化物同时催化去除碳烟和NOx的性能最佳,碳烟脱除率为50%的反应温度为301℃,N2产率为41.4%.实验结果表明,Co主要以氧化物形式均匀分散在Ce-La固溶体表面,Co3+与Co2+价态共存,离子间的变价有利于提高催化剂的氧化还原性能,有效降低了碳烟的起燃温度.La的引入增大了催化剂的比表面积,抑制了Ce O2晶粒长大,进而提高了N2产率.部分La和Co形成了微量的La Co O3,形成了更多氧空位,有利于提高催化氧化碳烟的活性.
Ce-based composite oxide catalysts were prepared by citric acid complexation method. The catalytic activity of the oxidized soot and the simultaneous removal of NOx were tested in thermogravimetric analyzer (TG) and tubular reactor respectively. , H2-TPR and XPS were used to investigate the structure of Co0.1 / C e La0.05 composite oxide, which showed the best performance for simultaneous removal of soot and NOx with the removal rate of 50% The yield of N2 is 41.4% at 301 ℃ .The experimental results show that Co is mainly dispersed in the form of oxide on the surface of Ce-La solid solution, Co3 + and Co2 + valence coexist, and the change between ions is beneficial to improve the redox performance of the catalyst. Reducing the ignition temperature of soot.The introduction of La increases the specific surface area of the catalyst and inhibits the growth of CeO2 grains and thus increases the yield of N2.The part of La and Co form a trace amount of LaCoO3 and form More oxygen vacancies, help to improve the catalytic oxidation of soot activity.