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用共沉淀法制备了Zn-Fe尖晶石型复合氧化物催化剂,用于有氧气氛中N2O的分解反应;考察了复合氧化物的组成、焙烧温度及K改性对其催化活性的影响,并用氮气吸附、XRD和H2-TPR等技术对催化剂结构进行了表征。结果表明,Zn-Fe尖晶石型复合氧化物具有良好的催化N2O分解的活性;在优化出的Zn0.8Fe0.2Fe2O4-400催化剂上500℃下连续反应10 h时,有氧无水和有氧有水条件下N2O转化率分别达到63.5%和22.2%。K改性Zn-Fe尖晶石型复合氧化物的催化活性均不及纯Zn-Fe氧化物,这是由于K改性催化剂的比表面积显著降低,而且K粒子迁移至催化剂表面,抑制了FeOx的还原和表面氧物种的脱除。
Zn-Fe spinel composite oxide catalyst was prepared by coprecipitation method for the decomposition reaction of N2O in an aerobic atmosphere. The effects of the composition of the composite oxide, the calcination temperature and the K modification on the catalytic activity were investigated. The structure of the catalyst was characterized by nitrogen adsorption, XRD and H2-TPR. The results show that the Zn-Fe spinel composite oxide has a good activity for catalyzing N2O decomposition. When the optimized Zn0.8Fe0.2Fe2O4-400 catalyst is continuously reacted at 500 ° C. for 10 h, Under the condition of oxygen and water, the conversion of N2O reached 63.5% and 22.2% respectively. The catalytic activity of K-modified Zn-Fe spinel composite oxide was lower than that of pure Zn-Fe oxide because the specific surface area of K-modified catalyst decreased significantly and K particles migrated to the catalyst surface, inhibiting the oxidation of FeOx Reduction and removal of surface oxygen species.