Micro-/Mesoporous Cu-Containing Eri, Ssz-13 and Zsm-5 Zeolites Applied in Nh3-Scr-Deno X

ERI, SSZ-13, and ZSM-5 were subjected to post-synthetic treatments (depending on the zeolite topology) to create micro-/mesoporous materials. The results of NH3-SCR-DeNOx show that the post-synthetic treatments improved the catalytic activity of the Cu-containing ERI-based materials, however, the NO conversion does not vary for the different materials treated with NaOH or NaOH/HNO3. For the Cu-containing SSZ-13 and ZSM-5, a lower NO conversion or no changes in NH3-SCR-DeNOx, respectively, are observed. The modification of the supports results in the presence of different amount and kind of copper species (especially isolated Cu2+ and aggregated Cu species) in the case of ERI- and SSZ-13-based samples. The activity of the catalysts is correlated with the formation of nitrates determined by applying in situ FT-IR. While the formation of μ-η2,η2-peroxo dicopper(II) intermediate is hampered at low temperatures in the presence of micro-/mesoporous Cu-SSZ-13 material, leading to its lower activity as compared to conventional Cu-SSZ-13.