Effect of Transition Metal Ion Properties on the Catalytic Functions and Sulfation Behavior of Zeolite-Based SCR Catalysts

Copper- and Iron- based metal-zeolite SCR catalysts are widely used in US and European diesel aftertreatment systems to achieve drastic reduction in NOx emission. These catalysts are highly selective to N2 under wide range of operating conditions. Nevertheless, the type of transition metal has a significant impact on the key performance and durability parameters such as NOx conversion, selectivity towards N2O, hydrothermal stability, and sensitivity to fuel sulfur content. In this study, we explained the differences in the performance characteristics of these catalysts based on their relative acidic-basic nature of transition metal present in these catalysts using practically relevant gas species present in diesel exhaust such as NO2, SOx, and NH3. These experiments show that Fe-zeolite has relatively acidic nature as compared to Cu-zeolite that causes NH3 inhibition and hence explains low NOx conversion on Fe-zeolite at low temperature under standard SCR conditions. Similarly, relatively basic nature of Cu-zeolite results in more prominent SOx storage and performance deactivation in the presence of acidic contaminant like SOx and required higher temperatures for desulfation as compared to Fe-zeolite.

• Record URL:
  https://doi.org/10.4271/2017-01-0939
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/19463936
• Supplemental Notes:
  • Abstract reprinted with permission of SAE International.
• Authors:
  • Kumar, Ashok
  • Kamasamudram, Krishna
  • Currier, Neal
  • Yezerets, Aleksey
• Conference:
  • WCX™ 17: SAE World Congress Experience
  • Location: Detroit Michigan, United States
  • Date: 2017-4-4 to 2017-4-6
• Publication Date: 2017-3-28

Language

• English

Media Info

• Media Type: Web
• Features: Figures; References; Tables;
• Pagination: pp 1604-1612
• Serial:
  • SAE International Journal of Engines
  • Volume: 10
  • Issue Number: 4
  • Publisher: SAE International
  • ISSN: 1946-3936
  • EISSN: 1946-3944
  • Serial URL: http://saeeng.saejournals.org/

Subject/Index Terms

• TRT Terms: Catalysts; Chemical properties; Chemical reactions and processes; Diesel engine exhaust gases; Emission control systems; Engines; Exhaust gases; Nitrogen oxides; Pollutants; Selective catalytic reduction
• Subject Areas: Highways; Vehicles and Equipment;

Filing Info

• Accession Number: 01642516
• Record Type: Publication
• Source Agency: SAE International
• Report/Paper Numbers: 2017-01-0939
• Files: TRIS, SAE
• Created Date: Mar 29 2017 4:45PM