Cu, Fe and Mn oxides intercalated SiO2 pillared magadiite and ilerite catalysts for NO decomposition

Abstract

Synthesized magadiite and ilerite samples were pillared with SiO2 and then intercalated with Cu, Fe and Mn oxides to utilize for direct NO decomposition between 400 and 600 °C. Cu-SiO2-pil-ile and Cu-SiO2-pil-mag catalysts exhibited high NO decomposition activity compared to Fe and Mn oxide intercalated catalysts. Remarkably, Cu-SiO2-pil-ile offered 90 % NO conversion and 83 % N2 selectivity at 600 °C. Elemental analysis, XRD, FESEM, DR UV-vis, Raman spectroscopy, N2-adsorption, H2-TPR, O2-TPD and XPS were utilized to study physicochemical characteristics of the materials. The results from XRD and N2 adsorption demonstrated that the samples possessed different pore structures from SiO2-pillared silicates, due to different nature of metal oxides. The Cu-SiO2-pil-ile and Cu-SiO2-pil-mag samples possess a smaller number of Lewis and Brønsted acid sites compared with Fe and Mn oxide intercalated samples. Presence of Cu2+/Cu+ and Fe3+/Fe2+, and synergism between redox centers are major reason for superior performance in NO decomposition. Therefore, the impact of redox properties and NO adsorption on the surface of the catalyst are significant.