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用溶胶凝胶法制备了一组Mn_xCo_(2.5-x)Al_(0.5)O_4尖晶石型三元复合氧化物,用于有氧气氛下的N_2O催化分解反应.用N_2物理吸附、X射线衍射(XRD)、扫描电镜(SEM)、H_2程序升温还原(H_2-TPR)、O_2程序升温脱附(O_2-TPD)、X射线光电子能谱(XPS)等技术对催化剂进行了结构表征,考察了催化剂组成、母液pH、K负载量等制备参数对其催化活性的影响.结果表明:K的加入弱化了催化剂表面的金属-氧化学键,有利于表面氧物种的脱除,改性催化剂有较高的催化活性和抗水性,其中母液pH=2、K/(Mn+Co)比为0.02的K/Mn_(0.2)Co_(2.3)Al_(0. 5)O_4催化剂活性较高,该催化剂在有氧、有氧有水气氛400℃连续反应50 h,N_2O转化率分别达98.5%和76.5%.
A series of Mn_xCo_ (2.5-x) Al_ (0.5) O_4 spinel ternary complex oxides were prepared by sol-gel method for the catalytic decomposition of N 2 O under aerobic conditions. The effects of N 2 physical adsorption, X-ray diffraction The structures of the catalysts were characterized by XRD, SEM, H_2 temperature-programmed reduction (H_2-TPR), O_2-temperature programmed desorption (O_2-TPD) and X-ray photoelectron spectroscopy (XPS) Catalyst composition, mother liquor pH, K loading on the catalytic activity of the catalyst.The results show that the addition of K weakens the metal-oxygen bond on the surface of the catalyst, which is favorable for the removal of surface oxygen species and the modification catalyst has higher The catalytic activity and water resistance of K / Mn 0.2 Co 2.3 Te 0.5 O 4 catalyst with pH = 2 and K / (Mn + Co) ratio of 0.02 were high, Oxygen, oxygen and water were continuously reacted at 400 ℃ for 50 h, the N 2 O conversion reached 98.5% and 76.5% respectively.