Preparation Of A Cobalt-based Oxide Catalyst And Its Catalytic Decomposition Of N 2 O

Nitrous oxide (N2O) is a kind of environmental polluting gases, which could exist in the stratosphere of the atmosphere for a long time. Excessive emissions of N2O will cause ozone hole, and also could cause the greenhouse effect considerably. Therefore, the production and emission of control efficiently has been a research hotspot for the catalytic researchers.At first, the main research object of the study is the CoxTi mixed oxide catalysts, in which N2O decomposition properties was discussed, especially its resistance to O2,H2O and NO. CoxTi mixed oxide catalysts were prepared by sol-gel, impregnation and coprecipitation method, studying the effects of calcination temperature on catalytic activity, The results show that Co0.6Ti catalysts using sol-gel synthesis of 500? calcination showed good catalytic activity. Besides, a series of CoxTi catalysts with different Co/Ti molar ratios were prepared by sol-gel method and used for N2O decomposition. The catalysts were characterized by XRD, XPS, TEM, H2-TPR, O2-TPD and Raman spectra measurements. The results indicate that the CoxTi catalysts possess high BET surface area, more surface Co3+ amount and even better structural stability than Co3O4 due to the strong interactions between the Co and Ti oxides. Coo.6Ti can keep near 100% N2O conversion for at least 30 h, however, the deactivation occurred with reaction time for Co3O4 catalyst, which are also investigated that decrease in surface Co3+ amount and poor structure stability. Moreover, the Coo.6Ti catalyst showed much stronger resistance against O2, H2O or NO in the feed than Co3O4 catalyst. In addition, a certain amount of CeO2 or CuO (small amunts of Cu excluded) can also decreased the catalysis activity using the Coo.6Ti catalyst prepared by sol-gel method. The incorporation of small amunts of Cu may cause a increased of the catalysis low temperature activity, which may be due to increase the reducibility of catalysts and promote the catalyst activity at low temperature. CeO2 formed on the catalyst surface control redox properties of cobalt species and reduce the catalytic activity.