The effect of copper-doped SBA-15 on catalytic oxidation of NO

Abstract

Cu/SBA-15 catalysts were prepared by the impregnation method using mesoporous siliceous SBA-15 as the support. The effects of different loadings of Cu/SBA-15 catalysts on the catalytic oxidation of NO were investigated. The physical and chemical properties of the Cu/SBA-15 catalysts were characterized by N₂ adsorption/desorption, SEM, XRD, TEM, FTIR, XPS, H₂-TPR and O₂-TPD. The characterization results suggested that the incorporation of copper did not disrupt the ordered hexagonal mesoporous structure of SBA-15. A lower copper loading was beneficial for increasing the dispersion of CuO_x on the surface of the support, thereby improving the activity of the catalyst. At loading above 10%, the CuO_x material aggregated into CuO_x clusters on the SBA-15 support and changed from an amorphous phase to a crystalline phase, reducing the catalytic activity. Moreover, the lower copper loading was beneficial for improving the reduction ability and desorption of surface chemisorbed oxygen of the catalyst. The experimental results indicated that 10% Cu/SBA-15 catalysts exhibited the highest activity, nearly 90% of NO conversion efficiency.