DOI QR코드

DOI QR Code

Selective Catalytic Reduction (SCR) of NOx with NH3 on Sb-promoted VWTi Catalysts

Sb 첨가에 따른 VWTi 촉매의 암모니아 선택적 촉매 환원(SCR)을 통한 질소산화물 저감

  • Kim, Su Bin (Department of Environmental Energy Engineering, Graduate School of Kyonggi University) ;
  • Choi, Gyeong Ryun (Department of Environmental Energy Engineering, Graduate School of Kyonggi University) ;
  • Shin, Jung Hun (Department of Environmental Energy Engineering, Graduate School of Kyonggi University) ;
  • Hong, Sung Chang (Department of Environmental Energy Engineering, Kyonggi University)
  • 김수빈 (경기대학교 일반대학원 환경에너지공학과) ;
  • 최경륜 (경기대학교 일반대학원 환경에너지공학과) ;
  • 신중훈 (경기대학교 일반대학원 환경에너지공학과) ;
  • 홍성창 (경기대학교 환경에너지공학과)
  • Received : 2020.11.30
  • Accepted : 2020.12.23
  • Published : 2021.02.10

Abstract

VWTi, which is used as a commercial catalyst in NH3-SCR, exhibits excellent denitrification performance at 300 to 400 ℃, but there is a problem that efficiency decreases at low temperatures below 300 ℃. Research on catalysts containing promoter to increase low-temperature denitrification efficiency is steadily progressing. However, research on the cause of the improvement in low-temperature denitrification efficiency of the catalyst and the catalyst properties is insufficient. In this study, it was confirmed that by adding Sb to VWTi, denitrification performance was improved by more than 10% in NH3-SCR reaction below 300 ℃. At this time, the space velocity and the size of the catalyst particles were controlled to exclude the influence of external/internal diffusion. In addition, the catalytic properties according to the presence or absence of Sb were investigated by performing BET, TEM/EDS, O2-TPD, H2-TPR and DRIFTs analysis. It was judged that the addition of Sb increased the adsorbed oxygen species on the surface of the catalyst, thereby enhancing the redox properties of the catalyst at low temperature and exhibiting excellent denitrification performance.

NH3-SCR에서 상용촉매로 사용되고 있는 VWTi (VOx/WO3-TiO2)는 300~400 ℃에서 우수한 탈질성능을 나타내지만 300℃ 이하 저온에서는 효율이 저하되는 문제가 있다. 저온 탈질효율을 높이기 위하여 promoter를 첨가한 촉매 연구는 꾸준히 진행되고 있으나 촉매의 저온 탈질효율 증진원인과 촉매특성에 관한 연구는 미비한 실정이다. 본 연구에서는 VWTi에 Sb(antimony)를 첨가함으로써 300 ℃ 이하의 NH3-SCR 반응에서 탈질 성능이 10% 이상 증진되는 것을 확인하였고, 이 때 외부확산/내부확산에 의한 영향을 배제하고자 공간속도와 촉매입자 크기를 제어하였다. 또한 Sb의 첨가 유·무에 따른 촉매특성을 BET, TEM/EDS, O2-TPD, H2-TPR, DRIFTs 분석을 수행하여 고찰하였다. Sb의 첨가는 촉매의 표면 흡착 산소 종을 증가시켰으며, 이에 따라 저온에서 촉매의 산화·환원(redox) 특성이 증진되어 우수한 탈질성능을 나타내는 것으로 판단되었다.

Keywords

References

  1. G. Qi and R. T. Yang, Performance and kinetics study for low-temperature SCR of NO with NH3 over MnOx-CeO2 catalyst, J. Catal., 217(2), 434-441 (2003). https://doi.org/10.1016/S0021-9517(03)00081-2
  2. P. S. Metkar, M. P. Harold, and V. Balakotaiah, Selective catalytic reduction of NOx on combined Fe- and Cu-zeolite monolithic catalysts: Sequential and dual layer configurations, Appl. Catal. B: Environ., 111-112, 67-80 (2012). https://doi.org/10.1016/j.apcatb.2011.09.019
  3. Y. Wu, B. Gu, J. W. Erisman, S. Reis, Y. Fang, X. Lu, and X. Zhang, PM2.5 pollution is substantially affected by ammonia emissions in China, Environ. Pollut., 218, 86-94 (2016). https://doi.org/10.1016/j.envpol.2016.08.027
  4. P. Forzatti, Present status and perspectives in de-NOx SCR catalysis, Appl. Catal. A: Gen., 222, 221-236 (2001). https://doi.org/10.1016/S0926-860X(01)00832-8
  5. Y. Ganjkhanlou, T. V. W. Janssens, P. N. R. Vennestrom, L. Mino, M. C. Paganini, M. Signorile, S. Bordiga, and G. Berlier, Location and activity of VOx species on TiO2 particles for NH3-SCR catalysis, Appl. Catal. B: Environ., 278, 119337 (2020). https://doi.org/10.1016/j.apcatb.2020.119337
  6. Y. Yang, M. Wang, Z. Tao, Q. Liu, Z. Fei, X. Chen, Z. Zhang, J. Tang, M. Cui, and X. Qiao, Mesoporous Mn-Ti amorphous oxides: A robust low-temperature NH3-SCR catalyst, Catal. Sci. Technol., 8, 6396-6406 (2018). https://doi.org/10.1039/C8CY01313F
  7. Y. Shan, J. Du, Y. Yu, W. Shan, X. Shi, and H. He, Precise control of post-treatment significantly increases hydrothermal stability of in-situ synthesized cu-zeolites for NH3-SCR reaction, Appl. Catal. B: Enviorn., 266, 118655 (2020). https://doi.org/10.1016/j.apcatb.2020.118655
  8. D. W. Kwon, K. H. Park, and S. C. Hong, The influence on SCR activity of the atomic structure of V2O5/TiO2 catalysts prepared by a mechanochemical method, Appl. Catal. A: Gen., 451, 227-235 (2013). https://doi.org/10.1016/j.apcata.2012.09.050
  9. L. J. Alemany, L. Lietti, N. Ferlazzo, P. Forzatti, G. Busca, E. Giamello, and F. Bregani, Reactivity and physicochemical characterization of V2O5-WO3/TiO2 De-NOx catalysts, J. Catal., 155, 117-130 (1995). https://doi.org/10.1006/jcat.1995.1193
  10. X. Liu, Z. Zhao, R. Ning, Y. Qin, T. Zhu, and F. Liu, Ce-Doped V2O5-WO3/TiO2 with low vanadium loadings as SCR catalysts and the resistance of H2O and SO2, Catal. Lett., 150, 375-383 (2020). https://doi.org/10.1007/s10562-019-03077-y
  11. L. Zhu, Z. Zhong, J. Xue, Y. Xu, C. Wang, and L. Wang, NH3-SCR performance and the resistance to SO2 for Nb doped vanadium based catalyst at low temperatures, J. Environ. Sci., 65, 306-316 (2018). https://doi.org/10.1016/j.jes.2017.06.033
  12. T. Yan, S. Wang, G. Xu, M. Wu, J. Chen, and J. Li, Promoter rather than inhibitor: Phosphorus incorporation accelerates the activity of V2O5-WO3/TiO2 catalyst for selective catalytic reduction of NOx by NH3, ACS Catal., 10(4), 2747-2753 (2020). https://doi.org/10.1021/acscatal.9b05549
  13. D. W. Kwon, D. H. Kim, and S. C. Hong, Promotional effect of antimony on the selective catalytic reduction NO with NH3 over V-Sb/Ti catalyst, Environ. Technol., 40, 2577-2587 (2019). https://doi.org/10.1080/09593330.2018.1491632
  14. D. H. Kim, D. W. Kwon, and S. C. Hong, Structural characteristics of V-based catalyst with Sb on selective catalytic NOx reduction with NH3, Appl. Surf. Sci., 538, 148088 (2021). https://doi.org/10.1016/j.apsusc.2020.148088
  15. C. Xu, J. Liu, Z. Zhao, F. Yu, K. Cheng, Y. Wei, A. Duan, and G. Jiang, NH3-SCR denitration catalyst performance over vanadium-titanium with the addition of Ce and Sb, J. Environ. Sci., 31, 74-80 (2015). https://doi.org/10.1016/j.jes.2014.09.040
  16. J. A. Dumesic, N. Y. Topsoe, H. Topsoe, Y. Chen, and T. Slabiak, Kinetics of selective catalytic reduction of nitric oxide by ammonia over vanadia/titania, J. Catal., 163, 409-417 (1996). https://doi.org/10.1006/jcat.1996.0342
  17. K. J. Lee, P. A. Kumar, M. S. Maqbool, K. N. Rao, K. H. Song, and H. P. Ha, Ceria added Sb-V2O5/TiO2 catalysts for low temperature NH3 SCR: Physico-chemical properties and catalytic activity, Appl. Catal. B: Environ., 142-143, 705-717 (2013). https://doi.org/10.1016/j.apcatb.2013.05.071
  18. Z. Huang, Y. Du, J. Zhang, X. Wu, H. Shen, and G. Jing, Exceptional activity over submonolayer MoO3 motif on TiO2 for nitrogen oxide emission abatement, Environ. Sci. Technol., 53, 5309-5318 (2019). https://doi.org/10.1021/acs.est.9b00665
  19. K. B. Nam, J. H. Yeo, and S. C. Hong, Study of the phosphorus deactivation effect and resistance of vanadium-based catalysts, Ind. Eng. Chem. Res., 58, 18930-18941 (2019). https://doi.org/10.1021/acs.iecr.9b01404
  20. J. S. Kim, D. H. Kim, and H. P. Ha, Investigating multi-functional traits of metal-substituted vanadate catalysts in expediting NOx reduction and poison degradation at low temperatures, J. Hazard. Mater., 397, 122671 (2020). https://doi.org/10.1016/j.jhazmat.2020.122671