Micro-/mesoporous copper-containing zeolite Y applied in NH3-SCR, DeNOx

Zeolite Y was prepared by a dense-gel method and subsequently modified either by treatment with diethylamine (DEA), sodium hydroxide (NaOH) or disodium ethylenediaminetetraacetate (Na(2)H(2)EDTA), or by sequential treatment (H(4)EDTA-NaOH or H(4)EDTA-NaOH-Na(2)H(2)EDTA). Individual treatment did not succeed in introducing mesoporosity in the parent zeolite Y, while the sequential treatment lead to formation of mesopores. After introduction of Cu2+ ions, the obtained materials were studied as catalysts for the selective catalytic reduction of NOx by NH3 (NH3-SCR, DeNO(x)). The catalytic investigations reveal a similar NO conversion for all Cu-containing catalysts up to 450?, independent of the introduced mesoporosity. Insights into the dynamics of NH3-SCR intermediates through rapid scan FT-IR show that for Cu-Y, the rate-determining step is the formation of the mixed [Cu(O-)(NH3)(n-1)(NO)](2+) complexes, which initiate the NH3-SCR reaction.

Automated summary

Mesopores were successfully introduced into zeolite Y through sequential treatment, and the resulting Cu2+-modified materials exhibited similar catalytic performance in NH3-SCR of NOx. Rapid scan FT-IR analysis revealed the rate-determining step in the catalytic reaction.