NH3-SCR over Cu-zeolite catalysts: activity and deactivation studies
Doctoral thesis, 2017
Cu‑SAPO-34
internal mass transfer limitation
NH3‑SCR
Cu-zeolite
hydrothermal aging
SO2 poisoning
Cu‑Beta
Cu‑SSZ‑13
Author
Kurnia Wijayanti
Chalmers, Chemistry and Chemical Engineering, Chemical Technology
Deactivation of Cu-SSZ-13 by SO2 exposure under SCR conditions
Catalysis Science and Technology,;Vol. 6(2016)p. 2565-2579
Journal article
Comparison of Cu/BEA, Cu/SSZ-13 and Cu/SAPO-34 for ammonia-SCR reactions
Catalysis Today,;Vol. 258(2015)p. 49-55
Journal article
Impact of sulfur oxide on NH3-SCR over Cu-SAPO-34
Applied Catalysis B: Environmental,;Vol. 166(2015)p. 568-579
Journal article
Mechanistic investigation of hydrothermal aging of Cu-Beta for ammonia SCR
Applied Catalysis B: Environmental,;Vol. 111(2012)p. 58-66
Journal article
Wijayanti, K, Xie K, Kumar A, Kamasamudram K, Olsson L, Effect of Gas Compositions on SO2 Poisoning over Cu-SSZ-13 Used for NH3 SCR
Wijayanti, K, Kumar A, Kamasamudram K, Olsson L. Effect of Internal Mass Transfer Limitations on Cu-SSZ-13 used for NH3-SCR
The susceptibility of Cu zeolites towards hydrothermal aging was investigated using Cu-Beta zeolite aged at 500-900 ⁰C. The SCR activity was readily altered by low temperature aging; however, the oxidation reactions were more significantly affected.
The high temperature stable copper chabazite (Cu-CHA) catalysts, such as Cu‑SAPO‑34 and Cu‑SSZ‑13, demonstrated higher activity than Cu‑Beta at low temperature; however, the presence of NO2 in SCR reaction resulted in more stable ammonium nitrate species hindering the activity of Cu-CHA catalysts at low temperature.
Deactivation caused by sulfur is one of the downside features of Cu zeolites which in this thesis, was examined for Cu‑SAPO‑34 and Cu‑SSZ‑13. The deactivation effect was more severe on standard SCR than on SCR in the presence of NO2. After SO2 poisoning, the activity was possible to recover by performing SCR reaction at high temperature. Further, depending on the gas compositions, copper sulfate and ammonium sulfate species were found during SO2 poisoning causing the decrease in catalytic activity.
The performance of monolithic catalyst system such as those used in diesel aftertreatment has been known to be affected both by kinetic reactions and mass transfer limitations. By varying the washcoat thickness and porosity, the presence of mass transfer in the washcoat was examined.
Finally, a deeper understanding of the mechanisms for catalytic reactions will facilitate the development of better catalysts in the future and strengthen the importance of catalysis for sustainable development.
Driving Forces
Sustainable development
Areas of Advance
Transport
Subject Categories
Other Chemical Engineering
Other Chemistry Topics
ISBN
978-91-7597-565-8
Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 4246
Publisher
Chalmers
KC-salen, Kemigården 4, Chalmers
Opponent: Dr. János Szanyi, Institute for Integrated Catalysis, Pacific Northwest National Laboratory, United States