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CO Transformation on Gold Catalysts – a Comparison with the Reaction on Pt/NbMCM-41

Klimas W., Sobczak I., Marie O., Bazin P., Daturi M., Ziolek M.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 9

1695-1695

EN

Silicate and niobosilicate MCM-41 were used as su ports for gold introduced by post synthesis impregnation or by co-precipitation during the synthesis. The latter sample (AuMCM-41) exhibited unique properties for the WGS reaction, as revealed by in situ FTIR and FTIR/MS OPERANDO techniques. AuMCM-41 is activated by CO through the formation of oxygen vacancies in volved in oxygen adsorption and activation for the further reaction. This behaviour is not characteristic for Pt/MCM-41 catalysts and appears only after the introduction of niobium into the mesoporous matrix (Pt/NbMCM-41).

2

Nanosorbents for selective removal of odours

Ziolek M., Sobczak I., Dudzik A., Konwicki Ł., Kujawa J.

Materials Science Poland

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2008

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Vol. 26, No. 2

425--431

EN

Y type zeolites modified with Cu, Ni, Mn as well as mesoporous hexagonally ordered silicates and niobosilicates of MCM-41 type with gold dispersed as an active component were studied in odour adsorption. Dibutyl sulfide and butyl amine were used as odour components and they were adsorbed separately and in the presence of high moisture content. The attractiveness of Au/MCM-41 samples for the selective adsorption of both odour compounds (much higher for the sulfide) and their possible further oxidation during the recovery of sorbents has been proved. The highest resistance for moisture adsorption was found for Au/NbMCM-41.

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Physicochemical Properties of CuAIMCM-41 and CuNbMCM-41 Mesoporous Molecular Sieves

Sobczak I., Ziołek M., Nowak I., Daturi M., Lavalley J.

Polish Journal of Chemistry

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2003

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Vol. 77 / nr 5

683-700

EN

The texture and surface properties of copper-containing aluminosilica and niobiosilica mesoporous molecular sieves of MCM-41 type, in which all elements were introduced during the synthesis, have been studied by means of XRD, N2 adsorption, H2-TPR, FTIR combined with pyridine and NO adsorption as well as in the skeletal region, and the test reaction. The results were compared with those obtained earlier for Cu post synthesis exchanged AlMCM-41 and NbMCM-41. All the results and this comparison allow the suggestion that copper is partially located in the skeleton of both MCM-41 materials, which exhibit redox and acidic properties.

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DeNO(x) na sitach molekularnych zawierających miedź. Cz.2. Katalityczny rozkład NO

Sobczak I., Ziółek M.

Wiadomości Chemiczne

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2002

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[Z] 56, 3-4

177-202

EN

Part II of the series dealing with DeNOx carried out on dopper-containing molecular sieves is devoted to the various features responsible for the catalytic activity of Cu-molecular sieves in the NO decomposition. The physico-chemical properties of the catalysts were shown in Part I ("Wiadomości Chemiczne" 2002, 56, 1-2, 83), whereas in Part II they are related to the decomposition of NO. This paper describes the role of the Si/Al and Cu/Al rations, the conditions of the catalysts preparation and activation, the influence of the T-element nature in the framework of molecular sieves as well as co-cations on the yield in the NO decomposition. Moreover, some proposals of the mechanism of this reaction described in the literature are included.

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De NO(x) na sitach molekularnych zawierających miedź. Cz.3. Selektywna katalityczna redukcja NO (SKR NO) węglowodorami. Wpływ O(2), H(2)O i SO(2)

Sobczak I., Ziółek M.

Wiadomości Chemiczne

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2002

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[Z] 56, 5-6

377-396

EN

Part I of this series exhibited the physico-chemical properties of Cu-containing molecular sieves, whereas, Part II was devoted to the DeNOx carried out via the decomposition of NO. Cu-containing molecular sieves are applied not only in the decomposition of NO but also in the selective catalytic reduction of NO with hydrocarbons (HC-SCR). The latter is the subject of this paper. The selective reduction of NO with hydrocarbons is a new alternative for the removal of NO from the exhausts gases. It is addressed, among others, to the reduction of NO in the presence of a large amount of oxygen. Part III considers also the influence of O2, H2 and SO2 on the activity of Cu-catalysts in both NO reduction with hydrocarbons and NO decomposition.

6

Characterisation of Cu-ZSM-5 zeolites by FTIR study - interaction with nitrogen oxide.

Sobczak I., Ziółek M.

Prace Naukowe Instytutu Chemii i Technologii Nafty i Węgla Politechniki Wrocławskiej. Konferencje

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1999

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Vol. 9, nr 56

147-152

EN

FTIR spectroscopy study were applied for measurements of the nature of Cu-NO complexes formed on Cu-ZSM-5 zeolites exibiting various Cu-exchange level. The influence of the activation temperature and the degree of Cu-exchange on the nature of complexes formed after NO adsorption and their decompositon, as well as the activity dependence on the thermal stability of the Cu + - NO species are considered. Nitrate/nitrite species were identified when Cu2+(O-NO(NO)complex was transformed under heating and evacuation, whereas nitrogen and oxygen were formed from Cu2+-No and Cu+-NO species, the latter being more active if is not too stable.

PL

Spektroskopię FTIR zastosowano do charakterystyki właściwości powierzchniowych zeolitów Cu-ZSM-5. Adsorpcja tlenku azotu w połączeniu z pomiarami FTIR pozwoliła na identyfikację form miedzi na powierzchni katalizatorów. Przeprowadzono badania wpływu temperatury aktywacji katalizatorów, poziomu stopnia wymiany na miedź oraz stabilności kompleksów Cu-NO na rozkład tlenku azotu. Stwierdzono, że aktywność zeolitów w rozkładzie NO zależy od m.in. stabilności kompleksu Cu+NO (pasmo IR przy 1811 cm -1), którego tworzenie jest w dużym stopniu uwarunkowane poziomem wymiany miedzi. Ponadto zaobserwowano przemianę kompleksu Cu2+NO (pasma IR przy 1897 i 1882 cm -1) przy stabilności Cu+NO na zeolitach aktywowanych w temperaturze 473 K. Formy azotanowe i/lub azotynowe powstają w wyniku przemiany kompleksu Cu2+(O-NO))NO) (pasmo IR przy ~1630 cm -1) w wyższych temperaturach.