NO reduction by CO over TiO_2-γ-Al_2O_3 supported In/Ag catalyst under lean burn conditions

TiO2/γ-Al2O3 supported In/Ag catalysts were prepared by impregnation method,and investigated for NO reduction with CO as the reducing agent under lean burn conditions.The microscopic structure and surface properties of the catalysts were studied by N2 adsorption-desorption,X-ray diffraction,transmission electron microscopy,X-ray photoelectron spectroscopy,ultraviolet-visible spectroscopy,H2 temperature-programmed reduction and Fourier transform infrared spectroscopy.TiO2/γ-Al2O3 supported In/Ag is a good catalyst for the reduction of NO to N2.It displayed high dispersion,large amounts of surface active components and high NO adsorption capacity,which gave good catalytic performance and stability for the reduction of NO with CO under lean burn conditions.The silver species stabilized and improved the dispersion of the indium species.The introduction of TiO2 into the γ-Al2O3 support promoted NO adsorption and improved the dispersion of the indium species and silver species.

Plasma cascaded solid wastes for possible adsorption of NO_(2)in diesel exhaust

Extensive use of fossil fuel has led to an increase in solid and gaseous particulates in the environment,which in turn necessitated newer,effective,and economical control strategies to abate pollutants,particularly gaseous pollutants.In the current research work,focus has been placed on utilizing industry wastes to adsorb nitrogen oxides present in diesel engine exhaust,which is pre-treated by plasma.Sampled exhaust from a 5 kW diesel generator is exposed to discharge plasma where the oxidation of nitric oxide to nitrogen dioxide occurs,which is then made to flow through another reactor filled with industry wastes drawn from agriculture,foundry,utility,marine industry,etc.,comprising mulberry waste,rice husk,wheat husk,areca nut husk,sugarcane bagasse,coffee husk,foundry sand,lignite ash,red mud,and oyster shells.While the adsorption of nitrogen dioxide was observed in all the wastes,reduction of nitric oxide was observed in metallic compound-based industry wastes.At about 184 J/L,specific energy plasma cascaded industrial waste red mud yielded 98%NO_(x)removal efficiency,and that with agriculture rice husk waste yielded 53%NOx removal.TiO_(2)/Fe_(2)O_(3)present in industry wastes might have exhibited photo-catalysis in visible light resulting in the possible reduction of NO.A new pathway for recycling the waste can be expected through nitrogen dioxide adsorption,and the results are further discussed with respect to plasma-alone and cascaded plasma adsorbent systems.