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Time-resolved copper speciation during selective catalytic reduction of NO on Cu-SSZ-13

Abstract

Practical catalysts often operate under dynamic conditions of temperature variations and sudden changes of feed composition that call for understanding of operation and catalyst structure under analogous experimental conditions. For instance, the copper-exchanged small-pore SSZ-13 catalyst used currently in the selective catalytic reduction of harmful nitrogen oxides from the exhaust gas of diesel-fuelled vehicles operates under recurrent ammonia dosage. Here, we report the design of unsteady state experiments that mimic such a dynamic environment to obtain key mechanistic information on this reaction. Through the combination of time-resolved X-ray absorption spectroscopy and transient experimentation, we were able to capture an ammonia inhibition effect on the rate-limiting copper re-oxidation at low temperature. The practical relevance of this observation was demonstrated by optimization of the ammonia dosage on a catalyst washcoat on cordierite honeycomb, resulting in lower ammonia consumption and an increase in nitrogen oxide conversion at low temperature.

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Fig. 1: Cu K-edge X-ray absorption near-edge structure spectra of Cu-SSZ-13 during transient experiments.
Fig. 2: Switching off the SCR reaction by NH3 removal.
Fig. 3: Initiation of the SCR reaction by NO addition.
Fig. 4: Temperature-dependent evolution of Cu species.
Fig. 5: Optimization of NH3 dosage in monolithic catalytic converters.

References

  1. 1.

    Nova, I. & Tronconi, E. Urea-SCR Technology for deNOx After Treatment of Diesel Exhausts (Springer, New York, 2014).

  2. 2.

    Nunney, M. J. Light and Heavy Vehicle Technology 4th edn (Routledge, New York, 2007).

  3. 3.

    Lamberti, C. & van Bokhoven, J. A. X-Ray Absorption and X-Ray Emission Spectroscopy (John Wiley & Sons, Chichester, 2016).

  4. 4.

    Kopelent, R. et al. Catalytically active and spectator Ce3+ in ceria-supported metal catalysts. Angew. Chem. Int. Ed. Engl. 54, 8728–8731 (2015).

    CAS  Article  Google Scholar 

  5. 5.

    Singh, J. et al. Generating highly active partially oxidized platinum during oxidation of carbon monoxide over Pt/Al2O3: in situ, time-resolved, and high-energy-resolution X-ray absorption spectroscopy. Angew. Chem. Int. Ed. Engl. 47, 9260–9264 (2008).

    CAS  Article  Google Scholar 

  6. 6.

    Paolucci, C. et al. Dynamic multinuclear sites formed by mobilized copper ions in NOx selective catalytic reduction. Science 357, 898–903 (2017).

    CAS  Article  Google Scholar 

  7. 7.

    Newton, M. A., Belver-Coldeira, C., Martínez-Arias, A. & Fernández-García, M. Dynamic in situ observation of rapid size and shape change of supported Pd nanoparticles during CO/NO cycling. Nat. Mater. 6, 528–532 (2007).

    CAS  Article  Google Scholar 

  8. 8.

    Nagai, Y. et al. In situ redispersion of platinum autoexhaust catalysts: an on-line approach to increasing catalyst lifetimes? Angew. Chem. Int. Ed. Engl. 47, 9303–9306 (2008).

    CAS  Article  Google Scholar 

  9. 9.

    Beale, A. M., Gao, F., Lezcano-Gonzalez, I., Peden, C. H. F. & Szanyi, J. Recent advances in automotive catalysis for NOx emission control by small-pore microporous materials. Chem. Soc. Rev. 44, 7371–7405 (2015).

    CAS  Article  Google Scholar 

  10. 10.

    Iwamoto, M. et al. Copper(II) ion-exchanged ZSM-5 zeolites as highly active catalysts for direct and continuous decomposition of nitrogen monoxide. J. Chem. Soc. Chem. Commun. 1272–1273 (1986).

  11. 11.

    Wang, J., Zhao, H., Haller, G. & Li, Y. Recent advances in the selective catalytic reduction of NOx with NH3 on Cu-chabazite catalysts. Appl. Catal. B 202, 346–354 (2017).

    CAS  Article  Google Scholar 

  12. 12.

    Kwak, J. H., Tonkyn, R. G., Kim, D. H., Szanyi, J. & Peden, C. H. F. Excellent activity and selectivity of Cu-SSZ-13 in the selective catalytic reduction of NOx with NH3. J. Catal. 275, 187–190 (2010).

    CAS  Article  Google Scholar 

  13. 13.

    Fickel, D. W., D’Addio, E., Lauterbach, J. A. & Lobo, R. F. The ammonia selective catalytic reduction activity of copper-exchanged small-pore zeolites. Appl. Catal. B 102, 441–448 (2011).

    CAS  Article  Google Scholar 

  14. 14.

    Paolucci, C., Di Iorio, J. R., Ribeiro, F. H., Gounder, R. & Schneider, W. F. Catalysis science of NOx selective catalytic reduction with ammonia over Cu-SSZ-13 and Cu-SAPO-34. Adv. Catal. 59, 1–107 (2016).

    Google Scholar 

  15. 15.

    Paolucci, C. et al. Catalysis in a cage: condition-dependent speciation and dynamics of exchanged Cu cations in SSZ-13 zeolites. J. Am. Chem. Soc. 138, 6028–6048 (2016).

    CAS  Article  Google Scholar 

  16. 16.

    Gao, F., Mei, D., Wang, Y., Szanyi, J. & Peden, C. H. F. Selective catalytic reduction over Cu/SSZ-13: linking homo- and heterogeneous catalysis. J. Am. Chem. Soc. 139, 4935–4942 (2017).

    CAS  Article  Google Scholar 

  17. 17.

    Gunter, T. et al. Structural snapshots of the SCR reaction mechanism on Cu-SSZ-13. Chem. Comm. 51, 9227–9230 (2015).

    Article  Google Scholar 

  18. 18.

    Gao, F. et al. Structure–activity relationships in NH3-SCR over Cu-SSZ-13 as probed by reaction kinetics and EPR studies. J. Catal. 300, 20–29 (2013).

    CAS  Article  Google Scholar 

  19. 19.

    Lomachenko, K. A. et al. The Cu-CHA deNOx catalyst in action: temperature-dependent NH3-assisted selective catalytic reduction monitored by operando XAS and XES. J. Am. Chem. Soc. 138, 12025–12028 (2016).

    CAS  Article  Google Scholar 

  20. 20.

    Janssens, T. V. W. et al. A consistent reaction scheme for the selective catalytic reduction of nitrogen oxides with ammonia. ACS Catal. 5, 2832–2845 (2015).

    CAS  Article  Google Scholar 

  21. 21.

    Tyrsted, C. et al. Nitrate–nitrite equilibrium in the reaction of NO with a Cu-CHA catalyst for NH3-SCR. Catal. Sci. Tech. 6, 8314–8324 (2016).

    CAS  Article  Google Scholar 

  22. 22.

    Doronkin, D. E. et al. Operando spatially- and time-resolved XAS study on zeolite catalysts for selective catalytic reduction of NOx by NH3. J. Phys. Chem. C 118, 10204–10212 (2014).

    CAS  Article  Google Scholar 

  23. 23.

    Borfecchia, E. et al. Revisiting the nature of Cu sites in the activated Cu-SSZ-13 catalyst for SCR reaction. Chem. Sci. 6, 548–563 (2015).

    CAS  Article  Google Scholar 

  24. 24.

    Marberger, A., Ferri, D., Elsener, M. & Kröcher, O. The significance of Lewis acid sites for the selective catalytic reduction of nitric oxide on vanadium-based catalysts. Angew. Chem. Int. Ed. Engl. 55, 11989–11994 (2016).

    CAS  Article  Google Scholar 

  25. 25.

    Gao, F. et al. Understanding ammonia selective catalytic reduction kinetics over Cu/SSZ-13 from motion of the Cu ions. J. Catal. 319, 1–14 (2014).

    CAS  Article  Google Scholar 

  26. 26.

    Zhang, T., Qiu, F., Chang, H., Li, X. & Li, J. Identification of active sites and reaction mechanism on low-temperature SCR activity over Cu-SSZ-13 catalysts prepared by different methods. Catal. Sci. Tech. 6, 6294–6304 (2016).

    CAS  Article  Google Scholar 

  27. 27.

    Nova, I., Ciardelli, C., Tronconi, E., Chatterjee, D. & Bandl-Konrad, B. NH3-SCR of NO over a V-based catalyst: low-T redox kinetics with NH3 inhibition. AIChE J. 52, 3222–3233 (2006).

    CAS  Article  Google Scholar 

  28. 28.

    Auvray, X. et al. Local ammonia storage and ammonia inhibition in a monolithic copper-beta zeolite SCR catalyst. Appl. Catal. B 126, 144–152 (2012).

    CAS  Article  Google Scholar 

  29. 29.

    Lezcano-Gonzalez, I. et al. Determination of the nature of the Cu coordination complexes formed in the presence of NO and NH3 within SSZ-13. J. Phys. Chem. C. 119, 24393–24403 (2015).

    CAS  Article  Google Scholar 

  30. 30.

    Paolucci, C. et al. Isolation of the copper redox steps in the standard selective catalytic reduction on Cu-SSZ-13. Angew. Chem. Int. Ed. Engl. 53, 11828–11833 (2014).

    CAS  Article  Google Scholar 

  31. 31.

    Metkar, P. S., Balakotaiah, V. & Harold, M. P. Experimental study of mass transfer limitations in Fe- and Cu-zeolite-based NH3-SCR monolithic catalysts. Chem. Engin. Sci. 66, 5192–5203 (2011).

    CAS  Article  Google Scholar 

  32. 32.

    Luo, J. et al. New insights into Cu/SSZ-13 SCR catalyst acidity. Part I: nature of acidic sites probed by NH3 titration. J. Catal. 348, 291–299 (2017).

    CAS  Article  Google Scholar 

  33. 33.

    Su, W., Li, Z., Peng, Y. & Li, J. Correlation of the changes in the framework and active Cu sites for typical Cu/CHA zeolites (SSZ-13 and SAPO-34) during hydrothermal aging. Phys. Chem. Chem. Phys. 17, 29142–29149 (2015).

    CAS  Article  Google Scholar 

  34. 34.

    Lonyi, F. & Valion, J. A TPD and IR study of the surface species formed from ammonia on zeolite H-ZSM-5, H-mordenite and H-beta. Thermochim. Acta 373, 53–57 (2001).

    CAS  Article  Google Scholar 

  35. 35.

    Delahay, G., Kieger, S., Tanchoux, N., Trens, P. & Coq, B. Kinetics of the selective catalytic reduction of NO by NH3 on a Cu-faujasite catalyst. Appl. Catal. B 52, 251–257 (2004).

    CAS  Article  Google Scholar 

  36. 36.

    Deka, U. et al. Confirmation of isolated Cu2+ ions in SSZ-13 zeolite as active sites in NH3-selective catalytic reduction. J. Phys. Chem. C 116, 4809–4818 (2012).

    CAS  Article  Google Scholar 

  37. 37.

    Kleemann, M., Elsener, M., Koebel, M. & Wokaun, A. Investigation of the ammonia adsorption on monolithic SCR catalysts by transient response analysis. Appl. Catal. B 27, 231–242 (2000).

    CAS  Article  Google Scholar 

  38. 38.

    Kröcher, O. et al. Investigation of the selective catalytic reduction of NO by NH3 on Fe-ZSM5 monolith catalysts. Appl. Catal. B 66, 208–216 (2006).

    Article  Google Scholar 

  39. 39.

    Zhao, Y., Hu, J., Hua, L., Shuai, S. & Wang, J. Ammonia storage and slip in a urea selective catalytic reduction catalyst under steady and transient conditions. Ind. Eng. Chem. Res. 50, 11863–11871 (2011).

    CAS  Article  Google Scholar 

  40. 40.

    Chiarello, G. L., Nachtegaal, M., Marchionni, V., Quaroni, L. & Ferri, D. Adding diffuse reflectance infrared Fourier transform spectroscopy capability to extended X-ray-absorption fine structure in a new cell to study solid catalysts in combination with a modulation approach. Rev. Sci. Instrum. 85, 074102 (2014).

    Article  Google Scholar 

  41. 41.

    Marchionni, V., Kambolis, A., Nachtegaal, M., Kröcher, O. & Ferri, D. High energy X-ray diffraction and IR spectroscopy of Pt/Al2O3 during CO oxidation in a novel catalytic reactor cell. Catal. Struct. React. 3, 71–78 (2017).

    CAS  Article  Google Scholar 

  42. 42.

    Müller, O., Nachtegaal, M., Just, J., Lützenkirchen-Hecht, D. & Frahm, R. Quick-EXAFS setup at the SuperXAS beamline for in situ X-ray absorption spectroscopy with 10 ms time resolution. J. Synchrotron Radiat. 23, 260–266 (2016).

    Article  Google Scholar 

  43. 43.

    Figueroa, S. J. A. & Prestipino, C. PrestoPronto: a code devoted to handling large data sets. J. Phys. Conf. Ser. 712, 012012 (2016).

    Article  Google Scholar 

  44. 44.

    Koebel, M., Elsener, M. & Madia, G. Recent Advances in the Development of Urea-SCR for Automotive Applications SAE Technical Paper 2001-01-3625 (SAE International, 2001); https://doi.org/10.4271/2001-01-3625

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Acknowledgements

The authors acknowledge financial support from the Swiss National Science Foundation and Competence Center for Materials Science and Technology.

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A.M. and A.W.P. designed the experiments, analysed the data, performed the LCF of the XAS data and prepared the catalysts. P.S. performed the catalytic tests and analysed the data. D.F., M.N. and O.K. led the project. D.F. and M.N. designed the experiments and analysed the data. All authors discussed the results and contributed to writing the manuscript.

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Correspondence to Maarten Nachtegaal or Davide Ferri.

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Supplementary Information

Supplementary Figures 1–10; Supplementary Discussion; Supplementary Tables 1–2; Supplementary Methods; Supplementary References

Supplementary Video 1

Time-resolved XPS.

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Marberger, A., Petrov, A.W., Steiger, P. et al. Time-resolved copper speciation during selective catalytic reduction of NO on Cu-SSZ-13. Nat Catal 1, 221–227 (2018). https://doi.org/10.1038/s41929-018-0032-6

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