Direct Decomposition of NO on Ba Catalysts Supported on Ce–Fe Mixed Oxides

Abstract

Cerium-iron mixed oxides were prepared by a glycothermal method, and NO decomposition reactions over these oxides and barium catalysts supported on them were examined. Although Ce–Fe mixed oxides (Ce–Fe(x), x = Fe/(Ce + Fe) molar ratio) exhibited only low activities for the direct decomposition of NO into N2 and O2, Ba catalysts supported on these mixed oxides are active for this reaction. The highest NO conversion was achieved with 3 wt% BaO/Ce–Fe(0.02). The NO conversion on this catalyst increased with increasing reaction temperature, and NO conversion was 51% at 800 °C. The high activity of this catalyst was maintained for more than 10 h and a relatively high NO conversion (23%) was obtained even in the presence of 5% oxygen. The XRD results indicated the formation of Ce–Fe(x) solid solutions with a cubic fluorite structure. The CO2-TPD results indicated NO decomposition activities of the catalysts were correlated with their basicities.