Fotokatalitik yöntemlerle oda koşullarinda hava aritimina yönelik NOx yükseltgenmesi ve depolanmasi

Air pollution is a serious environmental problem with a direct impact on human health. A variety of chemical compounds can be associated with air pollution and gaseous nitrogen oxides (NOx), such as NO and NO2, are especially among the most hazardous environmental pollutants.In this work, a hybrid technology for the photocatalytic oxidation and storage of gas phase NOx species is proposed where titania based powders are investigated as candidate photocatalytic materials. With this aim, various components of a thermally activated conventional NOx Storage/Reduction (NSR) catalyst is combined with a photocatalytically activated NOx oxidation catalyst to obtain a photocatalytically activated NOx oxidation and storage material. In this regard, TiO2/Al2O3 binary oxides and MxO/TiO2/Al2O3 ternary oxides were prepared and investigated.The photonic efficiencies of these samples were tested using a continuous flow system, composed of mass flow controllers, a custom-made UVA-illuminated reaction cell and an ambient chemiluminescence NOx analyzer. Photocatalytic performance of all samples were compared with that of a commercially available Degussa P25 TiO2 benchmark catalyst. Photocatalytic preformance tests revealed that the TiO2-Al2O3 binary oxides had much higher NOx storage capacities compared to Degussa P25 and the further addition of an alkaline earth oxide (BaO) storage component on TiO2-Al2O3 by physical mixing significantly enhanced the NOx capture in solid state and decreased unwanted gaseous NO2 emission to an almost negligible level. On the other hand, the ?incipient wetness impregantion? of metal nitrates resulted in metal titanate (MxTiyOz) formation on TiO2-Al2O3 binary oxide and diminished the photooxidation ability of the catalyst.