CeO Nanoparticle-Loaded MnO Nanoflowers for Selective Catalytic Reduction of NO with NH at Low Temperatures.

CeO nanoparticle-loaded MnO nanoflowers, prepared by a hydrothermal method followed by an adsorption-calcination technique, were utilized for selective catalytic reduction (SCR) of NO with NH at low temperatures. The effects of Ce/Mn ratio and thermal calcination temperature on the NH-SCR activity of the CeO-MnO nanocomposites were studied comprehensively. The as-prepared CeO-MnO catalysts show high NO reduction efficiency in the temperature range of 150-300 °C, with a complete NO conversion at 200 °C for the optimal sample. The excellent NH-SCR performance could be ascribed to high surface area, intimate contact, and strong synergistic interaction between CeO nanoparticles and MnO nanoflowers of the well-designed composite catalyst. The in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs) characterizations evidence that the SCR reaction on the surface of the CeO-MnO nanocomposites mainly follows the Langmuir-Hinshelwood (L-H) mechanism. Our work provides useful guidance for the development of composite oxide-based low temperature NH-SCR catalysts.