N-doped graphene/CoFe2O4 catalysts for the selective catalytic reduction of NOx by NH3 |
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| Authors: | Peng Li Zhifang Li Jinxing Cui Cui Geng Yan Kang Chao Zhang Changlong Yang |
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| Affiliation: | College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar 161006 Heilongjiang China, Fax: +86 452 2738206, +86 452 2738206 ; College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 Heilongjiang China ; Heilongjiang Provincial Key Laboratory of Polymeric Composite Material, Qiqihar 161006 Heilongjiang China |
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| Abstract: | In this paper, CoFe2O4/graphene catalysts and N-doped graphene/CoFe2O4 (CoFe2O4/graphene-N) catalysts were prepared using the hydrothermal crystallization method for the selective catalytic reduction of NOx by NH3. The results of the test showed that CoFe2O4/graphene catalysts exhibited the best denitrification activity when the loading was at 4% and the conversion rate of NOx reached 99% at 250–300 °C. CoFe2O4/graphene-N catalysts presented a better denitrification activity at low temperature than CoFe2O4/graphene catalysts, and the conversion rate of NOx reached more than 95% at 200–300 °C. The intrinsic mechanism of CoFe2O4/graphene-N catalysts in promoting SCR activity was preliminarily explored. The physicochemical properties of the samples were characterized using XRD, TEM, N2 adsorption, XPS, NH3-TPD, and H2-TPR. The results indicated that nitrogen doping can improve the dispersion of CoFe2O4, and it also increased the acidic sites and the redox performance conducive to improving the denitrification activity of the catalysts. In addition, CoFe2O4/graphene-N catalysts demonstrated a better resistance to water and sulfur than CoFe2O4/graphene catalysts.N-doped graphene/CoFe2O4 presented better denitrification activity than CoFe2O4/graphene due to the more uniform distribution of CoFe2O4 and acidic sites etc. |
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