CeO(2) Nanoparticle-Loaded MnO(2) Nanoflowers for Selective Catalytic Reduction of NO(x) with NH(3) at Low Temperatures

CeO(2) nanoparticle-loaded MnO(2) nanoflowers, prepared by a hydrothermal method followed by an adsorption-calcination technique, were utilized for selective catalytic reduction (SCR) of NO(x) with NH(3) at low temperatures. The effects of Ce/Mn ratio and thermal calcination temperature on the NH(3)–SCR activity of the CeO(2)-MnO(2) nanocomposites were studied comprehensively. The as-prepared CeO(2)-MnO(2) catalysts show high NO(x) reduction efficiency in the temperature range of 150–300 °C, with a complete NO(x) conversion at 200 °C for the optimal sample. The excellent NH(3)–SCR performance could be ascribed to high surface area, intimate contact, and strong synergistic interaction between CeO(2) nanoparticles and MnO(2) 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(2)-MnO(2) nanocomposites mainly follows the Langmuir–Hinshelwood (L-H) mechanism. Our work provides useful guidance for the development of composite oxide-based low temperature NH(3)–SCR catalysts.