The promotion effect of iron to Cu/ZSM‐5 catalyst for NOx removal by NH₃‐SCR

Abstract

The Cu/ZSM‐5 and Cu‐Fe/ZSM‐5 catalysts (ZSM‐5 with Si:Al ratio of 25:1) were created utilizing the liquid ion‐exchange technique. The effects of Fe on the physical and chemical characteristics of Cu/ZSM‐5 catalysts were investigated using X‐ray diffraction, field‐emission scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, nitrogen adsorption/desorption, and temperature‐programmed ammonia desorption. The coordination and valence state of copper and iron elements at intersections or in channels of ZSM‐5 was determined by the electron paramagnetic resonance technique. The effects of metal doping on the structure and catalytic activity of all catalysts were comprehensively investigated for NOx removal utilizing selective catalytic reduction with ammonia (NH3‐SCR). The results indicated that the promotion of iron significantly increased the NOx conversion and N2 selectivity of the Cu/ZSM‐5 catalyst for NH3‐SCR in the temperature range from 200 to 600 °C, and catalysts were highly resistant to high space velocity. This article describes a simple and uncomplicated method for synthesizing the commercially viable catalyst used in NH3‐SCR technology to reduce NOx emissions.