Preparation of Cu-Al/SiO2 porous material and its effect on NO decomposition in a cement kiln

Abstract

Nitrogen oxide (NOx) emissions have attracted much attention for increasing concern on the quality of the atmospheric environment. In view of NO decomposition in the cement production process, the preparation of Cu-Al/SiO2 porous material and its effect on NO decomposition were studied, and the denitrification mechanism was proposed in this paper. The NO decomposition performance of the Cu-Al/SiO2 porous material was tested via the experimental setup and infrared spectrometer and micro gas chromatography (GC). The result shows that the Cu-Al/SiO2 porous material with the template of cetyltrimethylammonium bromide (CTAB) had a better NO decomposition rate than materials with other templates when the temperature was above 500°C, and NO decomposition rate could approach 100% at high temperatures above 750°C. Structure analysis indicates that the prepared Cu-Al/SiO2 material structure was a mesoporous structure. The X-Ray Diffraction (XRD) and Ultraviolet-visible spectrophotometry (UV-Vis) results of the denitrification product show that the Cu-Al/SiO2 material mainly decomposed to Cu2O and Si2O, and the CuO decomposed to Cu2O and O2 at high temperature. The Cu(I)O was considered as the active phase. The redox process between Cu(II)O and Cu(I)O was thought to be the denitrification mechanism of the Cu-Al/SiO2 porous material.