Selective Catalytic Reduction (Scr) of Nox with Nh3 Over the Ssz-13/Zsm-5 Intergrowth Zeolite

Abstract

An intergrowth zeolite with a combined structure of SSZ-13 and ZSM-5 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 °C after hydrothermal aging (at 750 °C with 10% H2O for 16 hours). Comprehensive characterization revealed that intergrowth zeolite facilitates the loading of Cu2+, resulting in a higher amount of active Cu species on the catalyst. Additionally, copper leaching is hindered from its hybrid framework and reducibility of active sites is maintained during hydrothermal aging. The structural integrity of the intergrowth zeolite was preserved, with only a slight decrease in crystallinity (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.

Keywords: SSZ-13, ZSM-5, Intergrowth Zeolites, Selective Catalytic Reduction (SCR), NOx, Hydrothermal Stability