Thermal stability and SO2 resistance of Pd/Rh-perovskite based three-way catalyst wash-coated on cordierite monoliths


Bayram B., ÖNAL I., KÜLAH G.

CHEMICAL ENGINEERING COMMUNICATIONS, 2022 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Publication Date: 2022
  • Doi Number: 10.1080/00986445.2022.2030727
  • Journal Name: CHEMICAL ENGINEERING COMMUNICATIONS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Aqualine, Chimica, Communication Abstracts, Compendex, INSPEC, Metadex, Pollution Abstracts, Civil Engineering Abstracts
  • Keywords: Rh-Pd-Perovskite, SO2 poisoning, three-way catalysts, thermal stability, SELF-REGENERATION, OXIDATION CATALYST, PHASE-COMPOSITION, CARBON-MONOXIDE, CO OXIDATION, PD, TEMPERATURE, EXHAUST, OXIDE, DEACTIVATION
  • Middle East Technical University Affiliated: Yes

Abstract

The effect of hydrothermal aging and SO2 poisoning on the three-way catalytic performance of dispersed Pd/Rh-based and Pd/Rh perovskite-based catalysts were studied by using a dynamic activity test system that simulates redox fluctuations of gasoline engine exhaust conditions. Both catalysts were supported on ceria-zirconia-alumina and wash-coated on cordierite monoliths and were characterized by ICP-OES, BET, XRD, TEM-EDX, DRIFTS, and CO chemisorption. Their performance was very close when the catalysts were fresh but, after 3 h of hydrothermal aging at 1000 degrees C, the dispersed Pd/Rh-based catalyst lost its performance especially with respect to C3H8 and NO conversions; however, the Pd/Rh perovskite-based catalyst kept its activity. Parallel to that, CO uptake capacity losses after hydrothermal aging were 85% and 30% for the dispersed metallic catalyst and the perovskite-based catalyst, respectively. Moreover, 20 ppm SO2 exposure decreased CO uptake capacities by 61% and 48% for the two catalysts, respectively.