A great deal of attention has been focused on discharge plasma as it can rapidly decompose N_2O without additives,which is not only a kind of greenhouse gas but also a kind of damages to the ozone layer.The thermal eq...A great deal of attention has been focused on discharge plasma as it can rapidly decompose N_2O without additives,which is not only a kind of greenhouse gas but also a kind of damages to the ozone layer.The thermal equilibrium plasma is chosen to combine with catalysts to decompose N_2O,and its characteristics are analyzed in the present paper.The results indicate that NO and NO_2 were formed besides N_2 and O_2 during N_2O decomposition when N_2O was treated merely by discharge plasma.Concentration of NO declined greatly when the discharge plasma was combined with catalysts.Results of Raman spectra analysis on CeO_2,Ce_(0.75)Zr_(0.25)O_2and Ce_(0.5)Zr_(0.5)O_2 imply that the products selectivity has been obviously improved in discharge plasma decomposing N_2O because of the existence of massive oxygen vacancies over the composite oxide catalysts.展开更多
Three groups of cobalt mixed oxide catalysts(Mg/Zn–Co, Mg/Zn–Ce–C, K/Na–Mg/Zn–Ce–Co)were prepared by sol–gel or impregnation methods. The synergistic effects of transition metal, rare earth metal and alkali met...Three groups of cobalt mixed oxide catalysts(Mg/Zn–Co, Mg/Zn–Ce–C, K/Na–Mg/Zn–Ce–Co)were prepared by sol–gel or impregnation methods. The synergistic effects of transition metal, rare earth metal and alkali metal on cobalt mixed catalysts for nitrous oxide(N2O)decomposing to N2 and O2were investigated. The experimental results revealed that the catalytic activity for N2 O decomposition was promoted as Co2+was replaced partially by Zn2+/Mg2+, moreover, the characterization analysis by XRD and XPS showed that Zn2+/Mg2+replaced Co2+successfully into the spinel structure of Co3O4 and promoted significantly the catalytic activity. Especially, the addition of CeO2 and K2O/Na2O decreased the binding energy and resulted in an increase in the density of the electron cloud around Co and an improvement of the catalytic activity. Of the investigated cobalt mixed catalysts, the best catalytic activity was shown by 2% K–Zn0.5–Ce0.05–Co catalyst.展开更多
基金supported by National Natural Science Foundation of China(No.50677026)the Applied Basic Research Program of Wuhan,China(No.2015060101010068)
文摘A great deal of attention has been focused on discharge plasma as it can rapidly decompose N_2O without additives,which is not only a kind of greenhouse gas but also a kind of damages to the ozone layer.The thermal equilibrium plasma is chosen to combine with catalysts to decompose N_2O,and its characteristics are analyzed in the present paper.The results indicate that NO and NO_2 were formed besides N_2 and O_2 during N_2O decomposition when N_2O was treated merely by discharge plasma.Concentration of NO declined greatly when the discharge plasma was combined with catalysts.Results of Raman spectra analysis on CeO_2,Ce_(0.75)Zr_(0.25)O_2and Ce_(0.5)Zr_(0.5)O_2 imply that the products selectivity has been obviously improved in discharge plasma decomposing N_2O because of the existence of massive oxygen vacancies over the composite oxide catalysts.
基金supported by the Hi-Tech Research and Development Program (863) of China (No. 2012AA062501)the Natural Science Foundation of Hubei Province (No. 2009CDB246)the Postgraduates Innovation Foundation of Huazhong University of Science and Technology of China (No. HF-08-11-2011-261)
文摘Three groups of cobalt mixed oxide catalysts(Mg/Zn–Co, Mg/Zn–Ce–C, K/Na–Mg/Zn–Ce–Co)were prepared by sol–gel or impregnation methods. The synergistic effects of transition metal, rare earth metal and alkali metal on cobalt mixed catalysts for nitrous oxide(N2O)decomposing to N2 and O2were investigated. The experimental results revealed that the catalytic activity for N2 O decomposition was promoted as Co2+was replaced partially by Zn2+/Mg2+, moreover, the characterization analysis by XRD and XPS showed that Zn2+/Mg2+replaced Co2+successfully into the spinel structure of Co3O4 and promoted significantly the catalytic activity. Especially, the addition of CeO2 and K2O/Na2O decreased the binding energy and resulted in an increase in the density of the electron cloud around Co and an improvement of the catalytic activity. Of the investigated cobalt mixed catalysts, the best catalytic activity was shown by 2% K–Zn0.5–Ce0.05–Co catalyst.
