Catalytic activity of Cu/η-AlO catalysts prepared from aluminum scraps in the NH-SCO and in the NH-SCR of NO.

Copper-loaded η-alumina catalysts with different copper contents were prepared by impregnation/evaporation method. The catalysts were characterized by XRD, FTIR, BET, UV-Vis, and H-TPR and evaluated, for the first time, in the selective catalytic reduction of NO by NH and in the selective catalytic oxidation of NH. The characterization techniques showed that the impregnation/evaporation method permits to obtain highly dispersed copper oxide species on the η-alumina surface when a low amount of copper is used (1wt.

Catalytic decomposition of NO over Cu-Al-O mixed metal oxides.

Cu-Al-O mixed metal oxides with intended molar ratios of Cu/Al = 85/15, 78/22, 75/25, 60/30, were prepared by thermal decomposition of precursors at 600 °C and tested for the decomposition of nitrous oxide (deNO). Techniques such as XRD, ICP-MS, N physisorption, O-TPD, H-TPR, FT-IR and XAFS were used to characterize the obtained materials. Physico-chemical characterization revealed the formation of mixed metal oxides characterized by different specific surface area and thus, different surface oxygen default sites.

Selective catalytic reduction of nitrogen oxides over a modified silicoaluminophosphate commercial zeolite.

Nitrogen oxides (NO: NO, NO) are a concern due to their adverse health effects. Diesel engine transport sector is the major emitter of NO. The regulations have been strengthened and to comply with them, one of the two methods commonly used is the selective catalytic reduction of NO by NH (NH-SCR), NH being supplied by the in-situ hydrolysis of urea.

Valorization of vitreous China waste to EMT/FAU, FAU and Na-P zeotype materials.

In this study, Na-X, Na-P, SOD and EMT/FAU zeotype materials have been prepared from vitreous China waste by conventional hydrothermal route and alkaline fusion prior to hydrothermal synthesis. The conventional route has shown its limits in the activation of the waste in the chosen experimental conditions, [NaOH] = 3.5 M and T = 60 °C.

Ultrasound-assistant preparation of Cu-SAPO-34 nanocatalyst for selective catalytic reduction of NO by NH3.

The influence of the various preparation methods of Cu-SAPO-34 nanocatalysts on the selective catalytic reduction of NO with NH3 under excess oxygen was studied. Cu-SAPO-34 nanocatalysts were prepared by using four techniques: conventional impregnation (IM), ultrasound-enhanced impregnation (UIM), conventional deposition precipitation (DP) using NaOH and homogeneous deposition precipitation (HDP) using urea. These catalysts were characterized in detail by various techniques such as N2-sorption, XRD, TEM, H2-TPR, NH3-TPD and XPS to understand the catalyst structure, the nature and the dispersed state of the copper species, and the acid sites for NH3 adsorption.

A highly efficient silver niobium alumina catalyst for the selective catalytic reduction of NO by n-decane.

AgNb/Al(2)O(3) prepared by a nonhydrolytic sol-gel process is a highly efficient catalyst for NO(x) removal through selective catalytic reduction by hydrocarbons (HC-SCR). This result shows that the HC-SCR process remains a challenging method for lean engine DeNO(x).

Probing Cu(I)-exchanged zeolite with CO: DFT modeling and experiment.

Addition of CO on Cu-exchanged zeolite was investigated by means of quantum chemical calculations based on density functional theory. The aim of this investigation was to get insights about changes of electronic properties of a copper site with zeolite composition by using a CO probe molecule. Calculated nu(CO) frequency values show that various Si/Al ratios of faujasite zeolite reproduce the expected experimental decrease of the nu(CO) values with decreasing Si/Al ratio.

Theoretical study of N2O reduction by CO in Fe-BEA Zeolite.

Quantum mechanical (QM) and QM/molecular mechanics (MM) studies of the full catalytic cycle of N(2)O reduction by CO in Fe-BEA zeolite, that is, oxidation of BEA-Fe by N(2)O and reduction of BEA-Fe-alphaO by CO, is presented. A large QM cluster, representing half of the channel of the BEA zeolite, is used. The contribution of the MM embedding to the calculated activation energies is found to be negligible.

Novel non-hydrolytic synthesis of a V2O5-TiO2 xerogel for the selective catalytic reduction of NOx by ammonia.

A vanadia-titania mesoporous xerogel (10.5 wt% V(2)O(5)) was prepared from chloride precursors using a one-step non-hydrolytic sol-gel route and subsequent drying at ambient pressure; after calcination at 773 K for 5 h no crystalline V(2)O(5) was detected and the resulting mixed oxide exhibited remarkable activity in the selective reduction of NO with NH(3).

Selective catalytic reduction of NO by NH3 on Cu-faujasite catalysts: an experimental and quantum chemical approach.

The selective catalytic reduction (SCR) of NO by NH3 in the presence of O2 on Cu-faujasite (Cu-FAU) has been studied. Substitution of some Cu2+ with H+ and Na+ cations, compensating for the negative charge of the zeolite framework, forms the various CuHNa-FAU studied. The amount of Cu was held constant and the proportion of H+ and Na+ varied in the sample.