Experimental and numerical investigation of NO oxidation on Pt/Al2O3- and NOx storage on Pt/BaO/Al2O3-catalysts

Effects of temperature and inlet conditions on NO oxidation and NOx storage, as well as reduced NOx storage capacity over time – reflected by changes of measured NO concentration, which are reproduced by CFD using detailed reaction mechanisms.

Lithium cuprate, a multifunctional material for NO selective catalytic reduction by CO with subsequent carbon oxide capture at moderate temperatures

Li2CuO2 was evaluated as a possible catalyst for the NO selective catalytic reduction (NO SCR) by CO.

CdTe Quantum Dot-Functionalized P25 Titania Composite with Enhanced Photocatalytic NO2 Storage Selectivity under UV and Vis Irradiation

Composite systems of P25 (titania) functionalized with thioglycolic acid (TGA)-capped CdTe colloidal quantum dots (QDs) were synthesized, structurally characterized, and photocatalytically tested in the photocatalytic NO _x oxidation and storage during NO(g) + O₂(g) reaction. Pure P25 yielded moderate-to-high NO conversion (31% in UV-A and 40% in visible (vis)) but exhibited extremely poor selectivity toward NO _x storage in solid state (25% in UV-A and 35% in vis). Therefore, P25 could efficiently photooxidize NO(g) + O₂(g) into NO₂; however, it failed to store photogenerated NO₂ and released toxic NO₂(g) to the atmosphere. CdTe QD-functionalized P25 revealed a major boost in photocatalytic performance with respect to pure P25, where NO conversion reached 42% under UV-A and 43% under vis illumination, while the respective selectivity climbed up to 92 and 97%, rendering the CdTe/P25 composite system an efficient broad-band photocatalyst, which can harvest both UV-A and vis light efficiently and display a strong NO _x abatement effect. Control experiments suggested that photocatalytic active sites responsible for the NO(g) + O₂(g) photooxidation and formation of NO₂ reside mostly on titania, while the main functions of the TGA capping agent and the CdTe QDs are associated with the photocatalytic conversion of the generated NO₂ to the adsorbed NO _x species, significantly boosting the selectivity toward solid-state NO _x storage. Reuse experiments showed that photocatalytic performance of the CdTe/P25 system can be preserved to a reasonable extent with only a moderate decrease in the photocatalytic performance. Although some decrease in the photocatalytic activity was observed after aging, CdTe/P25 could still outperform P25 benchmark photocatalyst. Increasing CdTe QDs loading from the currently optimized minuscule concentrations could be a useful strategy to increase further the catalytic lifetime/stability of the CdTe/P25 system with only a minor penalty in catalytic activity.