The Manganese-Based Zirconium (Zr) and Chromium (Cr) Polymeric Pillared Interlayered Montmorillonite for the Low-Temperature Selective Catalytic Reduction of NOx by Ammonia (NH3) in Metallurgical Sintering Flue Gas
The manganese-based Zr and Cr polymeric pillared interlayered montmorillonite (Mn/Zr-Cr-PILM) with various Zr/Cr ratio as carrier supported MnOx were used in the selective catalytic reduction of NOx by NH3 (NH3-SCR) in metallurgical sintering flue gas. The X-ray diffraction (XRD), N2 adsorption–desorption isotherm, and ammonia temperature-programmed desorption (NH3-TPD) were used to analyze the catalyst physicochemical property. The Mn/Zr-Cr-PILM (1:3) had the highest NOx conversion between 140 and 180 °C compared with other catalysts. This was due to the large specific surface area and a large amount of Lewis acid sites provided more reaction platform and more adsorption sites for the catalytic reaction. However, as the proportion of Cr increased in Mn/Zr-Cr-PILM, the N2 selectivity of the catalyst decreased rapidly with the increasing temperature, except for Mn/Zr-Cr-PILM (3:1). It may be that the entry of chromium oxide into the zirconium oxide crystal phase in Mn/Zr-Cr-PILM (3:1) inhibited the production of N2O for increasing the N2 selectivity.
KeywordsLow-temperature NH3-SCR Pillared montmorillonite Excess oxygen
This research was supported by National Key Research and Development of China (2017YFB0603603) and National Natural Science Foundation of China (51576035).
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