Selective catalytic reduction (SCR) of NOx with NH3 over the SSZ-13/ZSM-5 intergrowth zeolite

An intergrowth zeolite combining the SSZ-13 and ZSM-5 structure was synthesized using a dual-template method for application in selective catalytic reduction (SCR) of NOx with NH3. The intergrown structure was confirmed through detailed characterization. Compared to pure-phase zeolites, the intergrowth exhibited up to a 14 % enhancement in NO conversion at temperatures above 220 degrees C after hydrothermal aging (at 750 degrees C with 10 % H2O for 16 h). Comprehensive characterization revealed that intergrowth zeolite promoted the transformation of hydrothermally less stable Cu species (ZCuOH, located at 8 MR) to hydrothermally more stable Cu species (Z(2)Cu, located at 6 MR) during hydrothermal ageing. Additionally, copper leaching is hindered due to the wellpreserved structural integrity of the intergrowth zeolite, with only a slight decrease in crystallinity (similar to 1.6 %). These findings suggest that intergrowth zeolites are promising candidates for mitigating NOx emissions in stationary sources under harsh hydrothermal conditions, such as that found in thermal power generation and steel manufacturing.