NH3-SCR-DeNOx Activity of Cu-Containing Commercial Zeolite Y

Commercial zeolite Y with different n(Si)/n(Al) ratios modified with copper cations were evaluated in the selective catalytic reduction of nitrogen oxide with ammonia (NH₃-SCR-DeNO_x). Among the investigated catalysts, the highest activity was achieved over CuY_CBV100 with 7.7 wt % of Cu. The activity of this sample was further confirmed in the feed of the tail gases stream from the pilot HNO₃ plant. The highest N₂ selectivity possesses CuY_CBV500 (3.7 wt % of Cu). To improve catalytic properties, both zeolites were mixed before ion exchange with copper, as well as in a more effective approach, both Cu-containing catalysts were physically mixed (in different weight ratios, 1:1, 1:9, 3:7, 7:3). CuY_CBV100 is more active due to the presence of more active sites, available in reduction/oxidation half-cycles.