Removal of gaseous pollutants by using 3DOM-based catalysts: A review.

Catalytic oxidation is a promising technique to control the emission of gaseous pollutants. Three-dimensionally ordered macroporous (3DOM)-based catalysts have aroused widespread attention because of their high porosity, large surface area and pore volume, superb ability of mass transfer. Therefore, they have been widely used in gaseous pollutants control field, such as soot and methane catalytic combustion, VOCs catalytic oxidation, photocatalytic CO2 reduction and so on. In this review, the recent studies about the preparation and applications of 3DOM catalysts are summarized. At the same time, the advantages and mechanism of the 3DOM catalysts used in gaseous pollutants control are introduced in depth. Finally, the perspective and future direction of 3DOM-based catalysts for gaseous pollutants control are proposed.

Enhancement of the activity of Cu/TiO2 catalyst by Eu modification for selective catalytic reduction of NOx with NH3.

The Cu/TiO2 catalysts with the addition of Eu were developed by the sol-gel way for the selective catalytic reduction (SCR) of NOx by NH3. Activity tests revealed that CuEu/TiO2-0.15 catalyst showed the optimal de-NOx performance in a wide temperature range (150-300 °C), along with an admirable SO2 tolerance. According to characterization analysis, the relationship between the NH3-SCR performance and physicochemical characters of samples was explored. The adjunction of Eu on Cu/TiO2 catalyst can contribute to the formation of a large amount of Cu2+, adsorbed oxygen, and acid sites on the catalyst surface. Moreover, the Eu addition on Cu/TiO2 is favorable to the generation of activated NOx and NH3 substances adsorbed on the catalyst surface, which would conduce to the NH3-SCR process by Langmuir-Hinshelwood (L-H) mechanism effectively.

Selective catalytic reduction of NOx by NH3 over CeVO4-CeO2 nanocomposite.

In this study, it was found that the CeVO4-CeO2 nanocomposite possessed remarkably selective catalytic reduction (SCR) performance and wider active temperature scope. And, the promotion principle was explored based on BET, XRD, XPS, H2-temperature-programmed reduction, NH3-temperature-programmed desorption, and in situ diffuse reflectance infrared Fourier transform (DRIFT) techniques. The characterization outcomes manifested that the CeVO4-CeO2 nanocomposite could inhibit its crystallinity and enhance the concentrations of chemisorbed oxygen species and Ce3+, which was advantageous to the SCR process. Moreover, the in situ DRIFT technique manifested that the NH3-SCR reaction over Ce0.75V0.25Oy was enhanced effectively through the mechanism of L-H.