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1

Selektywne katalityczne utlenianie (SCO) amoniaku do azotu i pary wodnej wobec mieszanych tlenków pochodzenia hydrotalkitowego – praca przeglądowa

Jabłońska M., Chmielarz L., Węgrzyn A.

Chemik

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2013

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Vol. 67, nr 8

701--710

PL

Selektywne katalityczne utlenianie amoniaku do azotu i pary wodnej jest obecnie uważane za jedną z najbardziej obiecujących metod usuwania amoniaku z gazów spalinowych i poprocesowych. W pracy omówiono technologię SCO, w tym stosowane w procesie katalizatory oraz mechanizmy przebiegu reakcji. Wykonano badania mieszanych tlenków pochodzenia hydrotalkitowego, w tym katalizatorów dwufunkcyjnych. Uzyskane wyniki jednoznacznie wskazują na duży potencjał materiałów hydrotalkitowych jako katalizatorów tego procesu. Zaproponowano dalsze kierunki badań w dziedzinie katalizatorów pochodzenia hydrotalkitowego dla procesu SCO.

EN

Selective catalytic oxidation of ammonia into nitrogen and water vapour is currently regarded as one of the most promising technologies for abatement of ammonia emissions from waste gases. This paper gives an overview of SCO technology, including the catalyst development and possible mechanisms of SCO reaction. The use of mixed metal oxides obtained from synthetic hydrotalcite-like materials in the role of catalysts for the SCO reaction has been reviewed. Obtained results clearly show huge potential of tested materials as industrial catalysts. Finally, future research directions in the area of NH3 oxidation based on mixed oxide catalysts derived from hydrotalcite-like materials are proposed.

2

N2O decomposition using modern micro-mesoporous materials with zeolitic properties

Rutkowska M., Chmielarz L., Macina D., Dudek B.

Archiwum Gospodarki Odpadami i Ochrony Środowiska

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2013

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Vol. 15, nr 3

89--96

EN

In the presented studies two modern approaches of synthesis of hierarchical micro-mesoporous materials with zeolitic properties are shown. In the first synthesis the protozeolitic particles were aggregated (under specified conditions) with simultaneous creation of mesopores between the zeolite seeds. In the second synthesis the zeolite nanoseeds were impregnated on the surface of mesoporous, amorphous SBA-15 material. Both used synthesis routs resulted in formation of combined micro-mesoporous materials with zeolitic properties, what was proven by nitrogen sorption, XRD, TGA and IRDRIFT measurements. The combination of zeolitic properties with mesopores (preferable diffusion rate) increased the accessibility of ion-exchange positions allowing the introduction of iron species nearly exclusively in the form of isolated cations. The prepared micro-mesoporous materials were tested as catalysts in low-temperature N2O decomposition in the presence of oxygen.

PL

Rozkład N2O przy użyciu nowoczesnych mikro-mezoporowatych materiałów o właściwościach zeolitów W niniejszej pracy przedstawiono syntezę hierarchicznych materiałów mikro-mezoporowatych o właściwościach zeolitu, przy użyciu dwóch nowoczesnych metod. W pierwszej z nich protozeolityczne nanozarodki ulegały agregacji w odpowiednich warunkach z utworzeniem mezoporowatych przestrzeni. Druga metoda syntezy polegała na impregnacji mezoporowatego materiału SBA-15 nanoziarnami zeolitu. W przypadku obu zastosowanych metod otrzymano materiały mikro-mezoporowate o właściwościach zeolitu, co zostało potwierdzone za pomocą takich metod jak niskotemperaturowa sorpcja azotu, XRD, TGA, oraz spektroskopia IR-DRIFT. Połączenie zalet mikroporowatych zeolitów z amorficznymi materiałami mezoporowatymi zwiększyło dostępność pozycji jonowymiennych w otrzymanych materiałach. Dzięki czemu do materiałów mikro-mezoporowatych wprowadzono żelazo praktycznie wyłącznie w formie oktaedrycznie skoordynowanych kationów Fe3+. Otrzymane materiały hierarchiczne zostały przebadane w roli katalizatorów niskotemperaturowego rozkładu N2O w obecności tlenu.

3

Mieszane tlenki Mg-Cu-Fe pochodzenia hydrotalkitowego jako katalizatory procesu selektywnego utleniania amoniaku do azotu i pary wodnej (SCO)

Jabłoński M., Chmielarz L., Węgrzyn A.

Chemik

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2012

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Vol. 66, nr 7

750-757

PL

Układy tlenkowe Mg-Cu-Fe pochodzenia hydrotalkitowego zostały przebadane jako katalizatory procesu selektywnego utleniania amoniaku do azotu i pary wodnej. Prekursory hydrotalkitowe zostały otrzymane metodą współstrącania, a następnie wysuszone i skalcynowane (600°C). Charakterystyka fizykochemiczna próbek obejmowała badania: strukturalne (XRD), teksturalne (BET), własności redoksowych (TPR). Eksperymenty katalityczne wykonano w układzie reaktora przepływowego. Analizę produktów reakcji przeprowadzono z zastosowaniem detektora QMS.

EN

Mixed oxide Mg-Cu-Fe systems obtained form hydrotalcites were tested as catalysts for the selective catalytic oxidation (SCO) of ammonia to nitrogen and water vapor. Catalytic precursors were obtained by coprecipitation method. In the next step hydrotalkite-like materials were dried and calcined (600°C). Physico-chemical characterization of the samples included the following studies: structural analysis (XRD), textural measurements (BET) and redox experiments (TPR). Catalytic studies were performed in a fixed-bed flow reactor system. Analysis of reaction products was performed using QMS detector.

4

Projekt CHEMEPASS

Chmielarz L., Frankowicz M.

Chemik

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2008

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Vol. 61, nr 1

27-28

5

Formation of active sites in thermally treated hydrotalcite-based catalysts for acetone aldolization

Kuśtrowski P., Sułkowska D., Chmielarz L., Paczyńska J., Dziembaj R.

Polish Journal of Chemical Technology

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2005

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Vol. 7, nr 1

33-37

EN

Mg-AI hydrotalcite containing CO3(2-) and NO3(-) as interlayer anions was synthesized according to the coprecipitation method at constant pH (9.0) and temperature (50°C), and then transformed into mixed metal oxides by calcination at 450, 500, 550 or 600°C for 8 h. The as-prepared hydrotalcite-like sample was characterized with respect to its structure (XRD), chemical composition (XRF, elemental analysis) and thermal stability (EGA-MS). Moreover, the textural features of the thermally activated hydrotalcite were examined using low-temperature (77 K) sorption of N2. Changes in the acid-base properties of the precursor calcined at different temperatures were studied by means of temperature-programmed desorptions of NH3 and CO2. It was found that the hydrotalcite-like sample calcined at 450°C, containing a part of non-decomposed interlayer anions, showed a rather low concentration of acidic and basic surface sites. The increase in the calcination temperature caused the removal of the interlayer anions, and an increase in the concentration and strength of the acidic and basic surface centers. The formation of high number of acid/ base surface sites resulted in raising the catalytic activity of the calcined hydrotalcites in the liquid-phase aldol condensation of acetone.

6

Production of isophorone by the vapour-phase self-condensation of acetone over the hydrotalcite-derived catalysts

Kuśtrowski P., Sułkowska D., Chmielarz L., Cap S.

Polish Journal of Chemical Technology

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2004

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Vol. 6, nr 4

41-46

EN

The magnesium-aluminum precursor with the structure of hydrotalcite, confirmed by XRD and FTIR, was transformed into mixed metal oxides by a thermal activation at 450, 500, 550 or 600°C for 16 h. The obtained catalysts were characterized with respect to their textural properties (surface area, total porosity and pore size distribution) and used in the gas-phase aldolization of acetone. The effect of reaction temperature and calcination conditions on the catalytic performance was studied. The highest initial conversion of acetone (87.1%) with the selectivity to isophorone of 89.7% was measured for the hydrotalcite-derived Mg-Al oxides calcined at 600°C in the reaction carried out at 240°C.

7

Syntetyczne hydrotalkity jako prekursory wysoko zdyspergowanych katalizatorów tlenkowych

Dziembaj R., Kuśtrowski P., Chmielarz L.

Przemysł Chemiczny

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2003

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T. 82, nr 3

170-173

8

Redukcja tlenków azotu wobec podpieranych montmorylonitów modyfikowanych jonami metali przejściowych

Chmielarz L., Kustrowski P., Zbroja M., Dziembaj R.

Przemysł Chemiczny

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2003

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T. 82, nr 8-9

678-681

9

Modelowanie kinetyki reakcji w badaniach metodą TPR katalizatorów tlenkowych

Surman J., Kustrowski P., Chmielarz L., Dziembaj R.

Przemysł Chemiczny

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2003

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T. 82, nr 8-9

783-785

10

Aktywowane termicznie hydrotalkity w roli katalizatorów rozkładu podtlenku azotu

Kuśtrowski P., Chmielarz L., Rafalska-Łasocha A., Dudek B., Węgrzyn A., Dziembaj R.

Przemysł Chemiczny

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2003

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T. 82, nr 8-9

732-735

11

Pillared montmorillonites modified with copper or cobalt as catalysts of DENOX with ammonia.

Chmielarz L., Zbroja M., Dudek B., Dziembaj R.

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

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2002

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Vol. 10, nr 57

451-456

EN

Al2O3 or TiO2 pillared montmorillonites modified with Cu or Co have been studied as catalysts for NO reduction with ammonia. The type of a pillaring agent, introduced transition metal, and preparation conditions strongly influenced catalytic performance of obtained materials. Among the studied samples, the highest catalytic activity was measured for Ti-pillared montmorillonites modified with copper. All studied catalysts were characterized by high selectivity towards N2.

12

Oxidative dehydrogenation of n-butane over transition metal containing hydrotalcite derived catalysts.

Kuśtrowski P., Chmielarz L., Węgrzyn A., Surman J., Dziembaj R.

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

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2002

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Vol. 10, nr 57

247-252

EN

Mg-Al layered double hydroxides containing carbonates and nitrates in theinterlayer gallery were used as parent materials for anion exchange. NO-3 and CO2-3 anions were exchanged with oxoanions containing vanadium, chromium, molybdenum and tungsten. Ion-exchange in basic solution led to introduction of V2O 4-7, CrO2-4, MoO2-4 and WO2-4 anions, while V10O286-, Cr2O2-7, Mo7O6-24 and W7O6-24 forms were intercalated in acidic solution. The intercalation was confirmed by X-ray diffraction and FTIR spectroscopy. Oxidative dehydrogenation of n-butane was carried out over hydrotalcite-derived catalysts. The catalysts obtained by thermal decompn. of V2O4-7-contg. Hydrotalcites appeared to be the most active ones in a prodn. of 1,3-butadiene. However, the highest yield of butenes was achieved over Mg-Al-Cr oxides catalyst in the low temp. range (Ł550C).

13

Kinetics and mechanism of decomposition of nitrous oxide over copper catalysts.

Chmielarz L., Kuśtrowski P., Dutkiewicz M., Dziembaj R.

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

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2002

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Vol. 10, nr 57

457-462

EN

Three different CuO-containing samples have been studied as catalysts for N2O decomposition. Among the studied samples, hydrotalcite-derived mixed oxides (CuO-MgO-Al2O3) have been found to be the most active catalyst. g-Alumina-supported copper oxide (CuO/Al2O3) was only slightly less active, while the catalytic activity of pure CuO was significantly lower than the rest of the samples. Only a very small amount of chemisorbed N2O has been found on the surface of the catalysts under the reaction conditions. N2 molecules produced from chemisorbed nitrous oxide desorbed directly to the gas phase, while part of oxygen was bonded to the catalyst surface.

14

Application of pillared clays modified with transition metals in reduction of NO with C2H4.

Chmielarz L., Zbroja M., Kuśtrowski P., Rafalska-Łasocha A., Dziembaj R.

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

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2002

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Vol. 10, nr 57

463-468

EN

Montmorillonites, pillared with Al2O3 or TiO2, were modified by introduction of transition metal (Cu or Co) by ion exchange method. Pillaring of clay with alumina caused significant increase of surface area and micropore volume due to increase of interlayer distance. Modification of montmorillonite with titania also resulted in increase of surface area and porosity, however pillared material was characterized by delaminated structure. Additionally, part of TiO2 was deposited on the sample surface in form of separate phase. Among the studied catalysts, titania pillared montmorillonites modified with copper have shown the highest activity in reduction of NO with ethylene in flue gas purifn.

15

Efektywność wymiany anionów CO3(2-) i NO(3-) na jony poliwanadanowe w hydrotalkitach Mg-Al

Węgrzyn A., Kuśtrowski P., Chmielarz L., Gębala P., Rafalska-Łasocha A., Dziembaj R.

Chemia i Inżynieria Ekologiczna

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2002

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Vol. 9, nr 5/6

677-684

PL

Hydrotalkity wyjściowe Mg-Al (Mg/Al = 2) różniące się względnym udziałem anionów azotanowych i węglanowych zsyntezowano poprzez współstrącanie przy zachowaniu stałego pH. Metodę wymiany jonowej wykorzystano do wprowadzenia anionów poliwanadanowych (V2074- i V100286- _ do przestrzeni międzywarstwowych hydrotalkitów. Efektywność przeprowadzonej wymiany określono metodą proszkowej dyfrakcji rentgenowskiej (XRD) i spektroskopii w podczerwieni (FTIR). Interkalacja anionów pirowanadanowych przebiega łatwiej w przypadku użycia jako materiałów wyjściowych hydrotalkitów azotanowych. Rodzaj anionu międzywarstwowego (COl-, N031 nie odgrywa natomiast istotnej roli przy wprowadzaniu anionów dekawanadanowych.

EN

Parent hydrotalcites Mg-Al (Mg/Al = 2) varying in fraction of carbonate and nitrate anions incorporated into the interlayer space were synthesized by coprecipitation at constant pH. Ion-exchange method was used to intercalate polyoxovanadate anions (V2O74- and V10O286-) into hydrotalcite structure. Efficiency of ion-exchange was characterized by powder X-ray diffraction (XRD) and lR spectroscopy. Intercalation of pyrovanadate anions occurs easier for nitrate-containing hydrotalcites, while no difference in efficiency of the ion-exchange in the case of decavanadates is observed.

16

Preparation, characterization and testing of hydrotalcite-derived polyoxovandate-intercalated catalysts for selective catalytic reduction of NO with NH3

Dziembaj R., Chmielarz L., Węgrzyn A., Kuśtrowski P.

Bulletin of the Polish Academy of Sciences. Chemistry

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2002

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Vol. 50, No. 2

237-248

EN

Mg-Al hydrotalcites were intercalated with deca- and bivanadate that was proved by FT-IR and XRD measurements. Thermal decomposition of these precursors resulted in formation of effective catalysts for selective catalytic reduction (SCR) of NO with NHs. The catalytic performance of vanadium catalysts was compared with Cu-containing mixed metal oxides obtained from hydrotalcite precursors. The calcined Cu-Mg-Al hydrotalcites have been found to be active in low-temperature region while the V-catalysts prevailed in high temperature SCR.

17

Influence of preparation method of hematite catalyst precursors on their catalytic activity in dehydrogenation of ethylbenzene to styrene

Kuśtrowski P., Surman J., Chmielarz L., Dziembaj R.

Polish Journal of Chemical Technology

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2000

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Vol. 2, nr 2

27-30

EN

A series of iron oxide based catalysts modified by introduction of chromium Cr, cerium Ce and potassium (KOH or K2CO3) promoters were prepared by coprecipitation method. KOH or K2C03were used as precipitating agents. Calcined catalyst precursors were characterised by XRD (structure) and low temperature Ar-sorption (specific surface area). Activity and selectivity of modified iron oxides were tested in dehydrogenation of ethylbenzene to styrene in fixed-bed microreactor system. Catalytic activity was influenced not only by introduced promoter (Cr, Ce, K) but also by kind of precipitating agent (KOH, K2CO3). The highest styrene yield was observed for iron oxide catalyst modified with cerium and potassium. All studied catalysts showed high selectivity towards styrene (>94%).