Research Institute of Inorganic Chemistry Inc.

Ústí nad Labem, Czech Republic

Research Institute of Inorganic Chemistry Inc.

Ústí nad Labem, Czech Republic
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Cmelik J.,Research Institute of Inorganic Chemistry Ltd | Nainarova Z.,J.E. Purkyne University in Ústí nad Labem | Rysanek P.,Research Institute of Inorganic Chemistry Ltd
International Journal of Environmental Analytical Chemistry | Year: 2015

The developed and tested method is based on the acid volatile sulphur (AVS) releasing from a sample of sediment by acidification with hydrochloric acid and sequential absorption of released hydrogen sulphide into the absorption solution of sodium hydroxide. Total sulphur absorbed in the absorption solution is subsequently determined by inductively coupled plasma optical emission spectrometry (ICP-OES) technique. The method was tested using both model and real samples of the river sediment. Obtained results were compared with the results of iodometric determination as the method routinely used for the AVS determination. In case of using ICP-OES with purge and trap, there is no spectral interference of calcium; therefore for the determination of sulphur, it is possible to use atomic emission line of sulphur S I 180.7 nm. The tested method provides the results comparable with the iodometric method within the range of tested concentrations. The detection limit (LOD) of this method is 0.09 mg· S2 − ∙ L−1 in the absorption solution which corresponds to 0.23 mg S2 −·kg−1 in a sediment. Value of LOD is comparable with the iodometric determination. © 2015 Taylor & Francis.


Cmelik J.,Research Institute of Inorganic Chemistry Ltd. | Nainarova Z.,J.E. Purkyne University in Ústí nad Labem | Rysanek P.,Research Institute of Inorganic Chemistry Ltd.
International Journal of Environmental Analytical Chemistry | Year: 2015

The developed and tested method is based on the acid volatile sulphur (AVS) releasing from a sample of sediment by acidification with hydrochloric acid and sequential absorption of released hydrogen sulphide into the absorption solution of sodium hydroxide. Total sulphur absorbed in the absorption solution is subsequently determined by inductively coupled plasma optical emission spectrometry (ICP-OES) technique. The method was tested using both model and real samples of the river sediment. Obtained results were compared with the results of iodometric determination as the method routinely used for the AVS determination. In case of using ICP-OES with purge and trap, there is no spectral interference of calcium; therefore for the determination of sulphur, it is possible to use atomic emission line of sulphur S I 180.7 nm. The tested method provides the results comparable with the iodometric method within the range of tested concentrations. The detection limit (LOD) of this method is 0.09 mg· S2− ∙ L−1 in the absorption solution which corresponds to 0.23 mg S2−·kg−1 in a sediment. Value of LOD is comparable with the iodometric determination. © 2015 Taylor & Francis


Stekrova M.,Åbo Akademi University | Stekrova M.,Institute of Chemical Technology Prague | Stekrova M.,Research Institute of Inorganic Chemistry Inc. | Kumar N.,Åbo Akademi University | And 8 more authors.
Applied Catalysis A: General | Year: 2014

α-Pinene oxide, an oxygenated derivative of α-pinene, can be converted into various valuable substances useful as flavour, fragrance and pharmaceutical compounds. Campholenic aldehyde is one of the most desired products of α-pinene oxide isomerization being a valuable intermediate for the production of sandalwood-like fragrances. Iron modified zeolites Beta-75 and ZSM-5, mesoporous material MCM-41, silica and alumina were prepared by two methods (impregnation and solid-state ion exchange) and tested for selective preparation of campholenic aldehyde by isomerization of α-pinene oxide. The characterization of tested catalyst was carried out using scanning electron microscope analysis, nitrogen adsorption measurements, pyridine adsorption-desorption with FTIR, X-ray absorption spectroscopy measurements, XPS-analysis, 29Si MAS NMR and 27Al MAS NMR and X-ray diffraction. The isomerization of α-pinene oxide was carried out in toluene as a solvent at 70 C. The main properties influencing the activity and the selectivity are the acidic and structural properties of the tested catalysts. The highest selectivity of 66% was achieved at complete conversion of α-pinene oxide with Fe-MCM-41. © 2013 Elsevier Ltd. All rights reserved.


Stekrova M.,Institute of Chemical Technology Prague | Stekrova M.,Research Institute of Inorganic Chemistry Inc. | Matouskova M.,Institute of Chemical Technology Prague | Vyskocilova E.,Institute of Chemical Technology Prague | Cerveny L.,Institute of Chemical Technology Prague
Research on Chemical Intermediates | Year: 2015

The presented report focuses on the isomerization of α-pinene oxide over methyltrioxorhenium (MTO) immobilized on a range of mesoporous materials with different SiO2/Al2O3 ratios, namely mesoporous alumina (m-Al2O3), aluminosilicates type Siral (with Al content 60-80 %), silica and MCM-41 or in its homogeneous form. Optimization of MTO immobilization has been studied and published previously. α-Pinene oxide, an oxygenated derivative of α-pinene, isomerizes rapidly into various valuable substances useful as flavors, fragrances and pharmaceutical compounds. Campholenic aldehyde is the one of the most desired products of α-pinene oxide isomerization, being a valuable intermediate for the production of sandalwood-like fragrances. The prepared catalytic systems were successfully used for selective preparation of campholenic aldehyde. Homogeneous and heterogenized MTO showed very high activity in α-pinene oxide isomerization (100 % conversion within a few minutes) and very high selectivity to campholenic aldehyde, amounting to over 80 %. Furthermore, the possibility of catalyst regeneration was proven. © 2015 Springer Science+Business Media Dordrecht.


Stekrova M.,Åbo Akademi University | Stekrova M.,Research Institute of Inorganic Chemistry Inc. | Stekrova M.,Institute of Chemical Technology Prague | Kumar N.,Åbo Akademi University | And 6 more authors.
Reaction Kinetics, Mechanisms and Catalysis | Year: 2013

High selectivity (82 %) to 3-methyl-6-(prop-1-en-2-yl)cyclohex-3-ene- 1,2-diol, a potent anti-Parkinson drug, was achieved in the isomerization of verbenol oxide at the conversion level of 96 % in N,N-dimethylacetamide at 140 °C over a metal modified zeolite, Fe-Beta-300 with SiO2 to Al2O3 ratio of 300. This catalyst exhibits both weak and medium strong Brønsted and Lewis acid sites. © 2013 Akadémiai Kiadó, Budapest, Hungary.


Stekrova M.,Åbo Akademi University | Stekrova M.,Institute of Chemical Technology Prague | Stekrova M.,Research Institute of Inorganic Chemistry Inc. | Kumar N.,Åbo Akademi University | And 3 more authors.
Catalysis Today | Year: 2014

The isomerisation of α-pinene oxide has been intensively investigated for selective preparation of campholenic aldehyde, a compound used in the synthesis of fragrances. Selective preparation of another product of α-pinene oxide rearrangement, trans-carveol, still remains a challenging task. Trans-carveol is a highly valuable compound used in perfume bases, food flavour compositions and as an active pharmaceutical substance in chemoprevention of mammary carcinogenesis. In the present work zeolite beta with different SiO2/Al2O3 molar ratios was modified by iron, characterised and tested per se and in the modified form for trans-carveol preparation from α-pinene oxide. The isomerisation reaction was carried out in a polar basic solvent N,N-dimethylacetamide at 140 °C. The activities and selectivities of the catalysts were correlated with their acid properties and with the iron content. © 2014 Elsevier B.V. All rights reserved.


Stekrova M.,Institute of Chemical Technology Prague | Stekrova M.,Research Institute of Inorganic Chemistry Inc. | Minarikova H.,Institute of Chemical Technology Prague | Vyskocilova E.,Institute of Chemical Technology Prague | And 2 more authors.
Journal of Porous Materials | Year: 2014

The presented report focuses on the testing of heterogenized methyltrioxorhenium (MTO) in indene epoxidation. A range of mesoporous materials with different SiO2/Al2O3 ratios, namely aluminosilicates type Siral and MCM-41 silica and fumed silica, were used as supports for immobilization of MTO. The tested support materials and prepared catalytic systems exhibited high surface area, well-defined regular structure and narrow pore size distribution of mesopores and therefore represent good quality catalysts for various reactions. The immobilized MTO on various supports was tested for the preparation of 1,2-epoxyindane using two forms of hydrogen peroxide as oxidation agents, namely aqueous solution of hydrogen peroxide and its anhydrous form, urea-hydrogen peroxide. The prepared catalysts were successfully used for the preparation of 1,2-epoxyindane with achieved 100 % selectivities to the desired product at high conversions of indene. © 2014, Springer Science+Business Media New York.


Stekrova M.,Institute of Chemical Technology Prague | Stekrova M.,Research Institute of Inorganic Chemistry Inc | Zizkova P.,Institute of Chemical Technology Prague | Vyskocilova E.,Institute of Chemical Technology Prague | And 2 more authors.
Journal of Porous Materials | Year: 2014

The current research is focused on the testing of titanium modified MCM-41 in indene epoxidation. Two preparation methods of Ti catalysts with mesoporous structure were tested, namely grafting of titanium on prepared MCM-41 (Ti/MCM-41/gr) and incorporation of titanium into the structure of MCM-41 by co-gelification method (Ti-MCM-41/cg). The tested catalysts exhibited high surface area, well-defined regular structure and narrow pore size distribution of mesopores and therefore represent potential good quality catalytic systems. The successful preparation of catalysts was confirmed by wide range of characterization methods (XRF, XRD, physical adsorption of N2, SEM, UV–Vis and FTIR). The catalytic activity of the prepared Ti catalysts was evaluated in indene epoxidation. The optimization of reaction conditions was performed using two types of oxidizing agents—aqueous solution of tert-butyl hydroperoxide and solution of tert-butyl hydroperoxide in decane. The prepared catalytic systems were successfully used for preparation of 1,2-epoxyindane with high yield (83 %) and the possibility of catalyst regeneration was proved. © 2014, Springer Science+Business Media New York.


Stekrova M.,Institute of Chemical Technology Prague | Stekrova M.,Research Institute of Inorganic Chemistry Co. | Vyskocilova E.,Institute of Chemical Technology Prague | Kolena J.,Research Institute of Inorganic Chemistry Co. | Cerveny L.,Institute of Chemical Technology Prague
Chemicke Listy | Year: 2013

Indene epoxidation is an important step in the synthesis of indene derivatives. This review is focused on various methods of 1,2-epoxyindane preparation. A wide range of oxidation agents (such as H2O2, organic hydroperoxides, NaIO4) and of catalysts, mostly organometallics based on Mn, Ti, Co, Re can be used for indene epoxidation.


Bortnovsky O.,Research Institute of Inorganic Chemistry Inc. | Bezucha P.,Research Institute of Inorganic Chemistry Inc. | Sazama P.,J. Heyrovsky Institute of Physical Chemistry | Dedecek J.,J. Heyrovsky Institute of Physical Chemistry | And 2 more authors.
Ceramic Engineering and Science Proceedings | Year: 2010

Geopolymers are generally XRD-amorphous materials; however recent research has proved that they contain nanometer particles probably with zeolitic structure. It has also been confirmed in our investigation that sodium in metakaolin-based geopolymer could be easily exchanged for other cations such as ammonium, cobalt, copper etc. Moreover, according to UV-VIS spectra of Co-geopolymer, it has been proven that the local arrangements of Co 2+- extraframework ions in cationic positions correspond to those known in high-silica zeolites, such as mordenite, ZSM-5 or beta. A similar high level of ion exchange with various ions of transition metals has also been reached for metakaolin-slag-based geopolymers. Accordingly, it could be truly expected that these metal-exchanging geopolymers would show similar properties and potential applications as zeolites, while keeping the advantages of the geopolymers, such as simple synthesis procedure, easy molding into complicated shapes or forming thin highly adhesive layers. These novel applications, such as heterogeneous catalysis for environmental applications and active antibacterial thin coating of metal-geopolymers will be presented and discussed.

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