Supported CuO+Ag/Partially Stabilized Zirconia Catalysts for the Selective Catalytic Reduction of NOx under Lean Burn Conditions

Садыков, В. А.; Bunina, R. V.; Alikina, G. M.; Иванова, А. С.; Кочубей, Д. И.; Новгородов, Б. Н.; Паукштис, E. A.; Фенелонов, В. Б.; Зайковский, В. И.; Кузнецова, Т. Г.; Beloshapkin, Sergey; Kolomiichuk, V. N.; Мороз, Э. М.; Матышак, В. А.; Konin, G. A.; Rozovskii, A. Ya.; Ross, J.R.H.; Breen, John

doi:10.1006/jcat.2001.3193

Cited by 31 publications

(14 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a result, the Zr-O bond in nanoparticles possesses a higher ionicity which is reflected in a higher energy of the charge transfer band. Decreased intensity of those bands in Zr PILCs can be related to a high disordering of the nanoparticle structure as revealed by EXAFS [8]. Wavcnumbcr, cmI Fig.…”

Section: Clay Structure and Texturementioning

confidence: 89%

“…FFIRS data of adsorbed CO and hydroxyl groups (not shown here for brevity ) indicate that on the surface of zirconia pillared clays evacuated at 400 TC, the number of coordinatively unsaturated Zr cations is much lower as compared with that for bulk highly dispersed zirconia samples [8]. Moreover, in the hydroxyls stretching regions, only bands at -3650-3700 cm -' corresponding to bridging hydroxyls are present.…”

Section: Clay Structure and Texturementioning

confidence: 92%

“…3), for Zr PILC the characteristic absorption corresponding to the anion-cation charge transfer is shifted to higher wavenumbers as compared with that for the bulk analog -highly dispersed cubic zirconia stabilized by 2 mol. % of CaO [8]. This feature can be explained by a lower O-Zr coordination number in nanosized pillars (maximum 2 for bridging oxygen anions or hydroxyls) as compared with the bulk zirconia lattice (each oxygen is surrounded by 4 Zr cations).…”

Section: Clay Structure and Texturementioning

confidence: 99%

See 2 more Smart Citations

Structure of Zirconia Nanoparticles used for Pillaring of Clay

et al. 2001

View full text Add to dashboard Cite

SAXS and EXAFS were applied to study genesis of polynuclear zirconium hydroxyspecies in pillaring solutions as dependent upon the zirconium concentration, addition of alkaline-earth chlorides and aging. After the montmorillonite clay pillaring, the structure of zirconium nanopillars was characterized by applying X-ray structural analysis, UV-Vis, FTIRS of adsorbed CO and nitrogen adsorption isotherms. Main pillaring species appear to be nanorods comprised of several Zr 4 tetramers. Basic structural features of the tetramers are preserved in zirconia nanoparticles fixed between alumosilicate layers in pillared clays. In calcined samples, those nanoparticles contain only bridging hydroxyls and/or oxygen anions responsible for bonding within pillars and between pillars and clay sheets.

show abstract

Section: Clay Structure and Texturementioning

confidence: 89%

Section: Clay Structure and Texturementioning

confidence: 92%

Section: Clay Structure and Texturementioning

confidence: 99%

See 1 more Smart Citation

Structure of Zirconia Nanoparticles used for Pillaring of Clay

et al. 2001

View full text Add to dashboard Cite

show abstract

“…This behavior indicates that this type of nitro species (probably bidentate) does not interact with the hydrocarbon under the experimental conditions. Finally, the appearance of the weak band at 2119 cm −1 characteristic of Cu + -CO carbonyl [7,[18][19][20][21][22]43,51] shows that the heating at 523 K leads to the formation of CO. Carbon monoxide can arise from partial oxidation of the adsorbed decane and decomposition of the formate species and formic acid.…”

Section: Interaction Of the Nomentioning

confidence: 99%

“…The results of TPD of adsorbed NO x species [22,23] and the IR data on the mechanism of SCR of NO by hydrocarbons on various oxide catalysts [24][25][26][27][28][29][30][31] reveal a reaction scheme that involves interaction of strongly adsorbed NO x − species (x is 2 or 3) with the hydrocarbon. However, only a few studies using in situ FT-IR spectroscopy have appeared on the identification of surface NO x species produced during the adsorption of NO on copper(II)-zirconia catalysts, whereas, many reports have been published dealing, for example, with copper-supported on zeolites and alumina [31].…”

Section: Introductionmentioning

confidence: 99%

FT-IR spectroscopic investigation of the reactivity of NOx species adsorbed on Cu2+/ZrO2 and CuSO4/ZrO2 catalysts toward decane

Kantcheva

2003

Applied Catalysis B: Environmental

View full text Add to dashboard Cite

The nature of the NO x species produced on NO adsorption and its co-adsorption with O 2 at room temperature on zirconia-supported copper(II) catalysts has been studied by means of in situ FT-IR spectroscopy. The samples were prepared by impregnation of zirconia with aqueous solutions of copper(II) nitrate and sulfate. The structural identification of the surface NO x complexes exhibiting absorptions in the fundamental nitro-nitrato region was performed by analyzing the combination bands of the nitrate species. In order to understand which factors control the selectivity of the catalysts in the catalytic reduction of NO by longer chain hydrocarbons, the stability of surface nitro-nitrato species and their reactivity toward adsorbed decane at various temperatures was investigated. The nitrates on the CuSO 4 /ZrO 2 catalyst are characterized by significantly lower thermal stability than the nitro-nitrato species on the Cu 2+ /ZrO 2 sample. The difference in the thermal stability of the NO x − species (x is 2 and 3) parallels their reactivity toward the adsorbed decane. The sulfate-free catalyst contains bidentate nitro species that are inert toward the hydrocarbon. The bidentate nitro species start to decompose to NO at temperatures higher than 523 K. In contrast, the nitrate species formed on the CuSO 4 /ZrO 2 catalyst are able to oxidize the adsorbed decane completely at 523 K producing acetates, formates, adsorbed CO and isocyanate species. It is proposed that the presence of stable nitro species on the sulfate-free copper(II)-zirconia catalyst is associated with its non-selective behavior above 573 K in the reduction of NO with decane in an excess of oxygen reported in the literature.

show abstract

Characterization of thin Co/ZrO₂ catalytic films by XPS, SEM and SAM

Stefanov

Atanasova

Robinson³

et al. 2002

Surface & Interface Analysis

View full text Add to dashboard Cite

Thin Co/ZrO 2 and Co/S-ZrO 2 catalytic films for hydrocarbon-selective catalytic reduction (HC-SCR) of NO x were prepared and characterized by means of XPS, SEM and scanning Auger microscopy (SAM). Zirconia was deposited on a fibrous inconel support (Bekaert) by the sol-gel method. Cobalt was deposited on pure and pre-sulphated zirconia films by impregnation with a 6% CoCl 2 solution. The photoelectron spectra indicated that cobalt was present mainly in the Co 2+ state in the form of CoO-like species. The SEM/SAM results showed homogeneous distribution and a smaller size of the Co particles deposited on pre-sulphated zirconia compared with cobalt deposited on pure zirconia. The results indicated that sulphating of zirconia improved the dispersion of cobalt on the surface, which is a prerequisite for a good SCR performance.

show abstract

Supported CuO+Ag/Partially Stabilized Zirconia Catalysts for the Selective Catalytic Reduction of NOx under Lean Burn Conditions

Cited by 31 publications

References 20 publications

Structure of Zirconia Nanoparticles used for Pillaring of Clay

Structure of Zirconia Nanoparticles used for Pillaring of Clay

FT-IR spectroscopic investigation of the reactivity of NOx species adsorbed on Cu2+/ZrO2 and CuSO4/ZrO2 catalysts toward decane

Characterization of thin Co/ZrO₂ catalytic films by XPS, SEM and SAM

Contact Info

Product

Resources

About

Supported CuO+Ag/Partially Stabilized Zirconia Catalysts for the Selective Catalytic Reduction of NOx under Lean Burn Conditions

Cited by 31 publications

References 20 publications

Structure of Zirconia Nanoparticles used for Pillaring of Clay

Structure of Zirconia Nanoparticles used for Pillaring of Clay

FT-IR spectroscopic investigation of the reactivity of NOx species adsorbed on Cu2+/ZrO2 and CuSO4/ZrO2 catalysts toward decane

Characterization of thin Co/ZrO2 catalytic films by XPS, SEM and SAM

Contact Info

Product

Resources

About

Characterization of thin Co/ZrO₂ catalytic films by XPS, SEM and SAM