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用共沉淀法制备了一组不同组成的MnxCo3-xO4尖晶石型复合氧化物,表面负载碱金属助剂制备改性催化剂,用于催化分解N2O.用X射线衍射(XRD)、N2物理吸附(BET)、红外光谱(FTIR)、扫描电镜(SEM)、H2程序升温还原(H2-TPR)、X射线光电子能谱(XPS)等技术表征催化剂结构.考察了复合氧化物组成、碱金属助剂类型、钾前驱物等制备参数对催化剂结构和催化活性的影响.结果表明:添加助剂K、Cs降低了催化剂表面Co、Mn元素的电子结合能,弱化了Co—O和Mn—O键,有利于氧物种的脱除,提高了催化剂活性.优化出了活性较高的催化剂K/Mn0.4Co2.6O4(K2CO3),有氧无水、有氧有水气氛400℃连续反应50 h,N2O转化率分别保持100%和74.2%,催化剂稳定性较高.
A series of MnxCo3-xO4 spinel composite oxides with different compositions were prepared by coprecipitation method, and the surface supported alkali metal promoter was used to prepare the modified catalyst for catalytic decomposition of N2O. XRD, N2 physical adsorption The structures of the catalysts were characterized by BET, FTIR, SEM, H2-TPR and XPS.The effects of the composition of the composite oxide, Agent type and potassium precursor on the structure and catalytic activity of the catalysts were studied.The results showed that the addition of K and Cs reduced the electron binding energies of Co and Mn on the catalyst surface and weakened the Co-O and Mn-O bonds , Is conducive to the removal of oxygen species, increased catalyst activity.Optimized the higher activity of the catalyst K / Mn0.4Co2.6O4 (K2CO3), aerobic anhydrous, aerobic water environment 400 ℃ continuous reaction 50 h, N2O conversion rate of 100% and 74.2%, respectively, catalyst stability is high.