Applied Chemistry for Engineering (공업화학)

The Korean Society of Industrial and Engineering Chemistry (한국공업화학회)
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The Effect of Alkali Metal Ions (Na, K) on NH3-SCR Response of V/W/TiO2

알칼리 금속 이온(Na, K)이 V/W/TiO2의 NH3-SCR 반응인자에 미치는 영향

  • Yeo, Jonghyeon (Department of Environmental Energy Engineering, Graduate school of Kyonggi University) ;
  • Hong, Sungchang (Department of Environmental Energy Engineering, Kyonggi University)
  • 여종현 (경기대학교 일반대학원 환경에너지공학과) ;
  • 홍성창 (경기대학교 환경에너지공학과)
  • Received : 2020.08.27
  • Accepted : 2020.09.23
  • Published : 2020.10.12
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Abstract

In this study, we investigated that the effect of alkali metals [Na(Sodium) and K(Potassium)], known as representative deactivating substances among exhaust gases of various industrial processes, on the NH3-SCR (selective catalytic reduction) reaction of V/W/TiO2 catalysts. NO, NH3-TPD (temperature programmed desorption), DRIFT (diffuse reflectance infrared fourier transform spectroscopy analysis), and H2-TPR analysis were performed to determine the cause of the decrease in activity. As a result, each alkali metal acts as a catalyst poisoning, reducing the amount of NH3 adsorption, and Na and K reduce the SCR reaction by reducing the L and B acid points that contribute to the reaction activity of the catalyst. Through the H2-TPR analysis, the alkali metal is considered to be the cause of the decrease in activity because the reduction temperature rises to a high temperature by affecting the reduction temperature of V-O-V (bridge oxygen bond) and V=O (terminal bond).

본 연구는 다양한 산업공정의 배가스 중 대표적인 활성저하 물질로 알려진 알칼리 금속[Na(Sodium)과 K(Potassium)]이 V/W/TiO2 촉매의 NH3-SCR 반응에 미치는 영향을 확인 하였다. 이에 따른 활성 저하 원인을 규명하고자 NO, NH3-TPD, DRIFT, H2-TPR 분석을 수행 하였다. 그 결과, 각 알칼리 금속은 촉매 피독으로 작용하여 NH3 흡착양이 저하되고, Na과 K은 촉매의 반응 활성에 기여하는 L산점과 B산점을 감소시켜 SCR 반응을 저하시킨다. H2-TPR 분석을 통하여 알칼리 금속은 V-O-V (bridge oxygen bond)와 V=O (terminal bond)의 환원 온도에 영향을 끼쳐, 환원 온도가 고온으로 올라가기 때문에 활성 저하 원인으로 판단된다.

Keywords

References

  1. M. Shelef, Selective catalytic reduction of NOx with N-free reductants, Chem. Rev., 95, 209-225 (1995). https://doi.org/10.1021/cr00033a008
  2. V. I. Parvulescu, P. Grange, and B. Delmon, Catalytic removal of No, Catal. Today, 46, 233-316 (1998). https://doi.org/10.1016/S0920-5861(98)00399-X
  3. S.-U. Park and Y.-H. Lee, Spatial distribution of wet deposition of nitrogen in South Korea, Atmos. Environ., 36, 619-628 (2002). https://doi.org/10.1016/S1352-2310(01)00489-7
  4. L. Casagrande, L. Lietti, I. Nova, P. Forzatti, and A. Baiker, SCR of NO by $NH_3$ over $TiO_2$-supported $V_2O_5-MoO_3$ catalysts: Reactivity and redox behavior, Appl. Catal. B, 22, 63-77 (1999). https://doi.org/10.1016/S0926-3373(99)00035-1
  5. K. Skalask, J.S. Miller, and S. Ledakowicz, Trends in Nox abatement L: A review, Sci. Total Environ., 408, 3976-3989 (2010). https://doi.org/10.1016/j.scitotenv.2010.06.001
  6. R. Khodayari and C. U. I. Odenbrand, Regeneration of commercial $TiO_2-V_2O_5-WO_3$ SCR catalysts used in bio fuel plants, Appl. Catal. A, 80, 87-99 (1992).
  7. O. Krocher and M. Elsener, Chemical deactivatiaon of $V_2O_5/WO_3-TiO_2$ SCR catalysts by additives and impurities from fuels, lubrication oils, and urea solution. I. Catalytic studies, Appl. Catal. B, 75, 215-227 (2008).
  8. D. Nicosia, I. Czekaj, and O. Krocher, Chemical deactivation of $V_2O_5/WO_3-TiO_2$ SCR catalysts by additives and impurities from fuels, lubrication oils and urea solution. Part 2. Characterization study of the effect of alkali and alkaline earth metals, Appl. Catal. B, 77, 228-236 (2008). https://doi.org/10.1016/j.apcatb.2007.07.032
  9. Y. Peng, J. Li, L. Chen, J. Chen, J. Han, H. Zhang, and W. Han, Alkali metal poisoning of a $CeO_2-WO_3$ catalyst used in the selective catalytic reduction of NOx with $NH_3$: An experimental and theoretical study, Environ. Sci. Technol., 46, 2864-2869 (2012). https://doi.org/10.1021/es203619w
  10. T. Shikada and K. Fujimoto, Effect of added alkali salts on the activities of supported vanadium oxide catalysts for nitric oxide redution, Chem. Lett., 12, 77-80 (1983). https://doi.org/10.1246/cl.1983.77
  11. P. Forzatti, Present status and perspectives in de-NOx SCR catalysis. Appl. Catal. A, 222, 221-236 (2001). https://doi.org/10.1016/S0926-860X(01)00832-8
  12. X. L. Zhang, Z. G. Huang, and Z. Y. Liu, Effect of KCl on selective catalytic reduction of NO with $NH_3$ over a $V_2O_5/AC$ catalyst, Catal. Commun., 9, 842-846 (2008). https://doi.org/10.1016/j.catcom.2007.09.008
  13. J.-K. Lai and I. E. Wachs, A perspective on the selective catalytic reduction (SCR) of NO with $NH_3$ by supported $V_3O_5-WO_3/TiO_2$ catalysts, ACS Catal., 8, 6537-6551 (2018). https://doi.org/10.1021/acscatal.8b01357
  14. G. Ramis, L. Yi, and G. Busca, Ammonia activation over catalysts for the selective catalytic reduction of Nox and the selective catalytic reduction of NOx and the selective catalytic oxidation of $NH_3$. And FT-IR study, Catal. Today, 28, 373-380 (1996). https://doi.org/10.1016/S0920-5861(96)00050-8
  15. M. A. Larrubia, G. Ramis, and G. Busca, An FT-IR study of the adsorption of urea and ammonia over $V_2O_5-MoO_3-TiO_2$ SCR catalysts, Appl. Catal, B, 27, 145-151 (2000).
  16. L. Chen, J. Li, and M. Ge, DRIFT study on cerium-Tungsten/Titiania catalyst for selective catalytic reduction of NOx with $NH_3$, Environ. Sci. Technol., 44, 9590-9596 (2010). https://doi.org/10.1021/es102692b
  17. F. Tang, B. Xu, H. Shi, J. Qiu, and Y. Fan, The poisoning effect of $Na^+$ and $Ca^{2+}$ ions doped on the $V_2O_5/TiO_2$ catalysts for selective catalytic reduction of NO by $NH_3$, Appl. Catal. B, 94, 71-76 (2010). https://doi.org/10.1016/j.apcatb.2009.10.022
  18. D. A. Bulushev, L. Kiwi-Minsker, R. Rainone, and A. Renken, Characterization of surface vanadia forms on V/Ti-Oxide catalyst via temperature-programmed reduction in hydrogen and spectroscopic methods, J. Catal., 205, 115-122 (2002). https://doi.org/10.1006/jcat.2001.3427
  19. A. Sorrentino, S. Rega, D. Sannino, A. Magliano, P. Ciambelli, and E. Santacesaria, Performances of $V_2O_5$-based catalysts obtained by grafrting vanadyl tri-isopropoxide on $TiO_2-SiO_2$ in SCr, Appl. Catal. A, 209, 45-57 (2001). https://doi.org/10.1016/S0926-860X(00)00742-0
  20. E. Tronconi, I. Nova, C. Ciardelli, D. Chatterjee, and M. Weibel, Redox features in the catalytic mechanism of the "standard" and "fast" $NH_3-SCR$ of NOx over a V-based catalyst investigated by dynamic methods, J. Catal., 245, 1-10 (2007). https://doi.org/10.1016/j.jcat.2006.09.012