Search results

Search:
in the keywords: catalysts

Sort By:

Limit search:

Preparation and characterization of multi-walled carbon nanotubes grown on transition metal catalysts

100%

Pełech I., Narkiewicz U., Kaczmarek A., Jędrzejewska A.

Polish Journal of Chemical Technology

2014

vol. 16

issue 1

117-122

Transition metal catalysts (mainly: iron, cobalt and nickel) on various supports are successfully used in a largescale production of carbon nanotubes (CNTs), but after the synthesis it is necessary to perform very aggressive purification treatments that cause damages of CNTs and are not always effective. In this work a preparation of unsupported catalysts and their application to the multi-walled carbon nanotubes synthesis is presented. Iron, cobalt and bimetallic iron-cobalt catalysts were obtained by co-precipitation of iron and cobalt ions followed by solid state reactions. Although metal particles were not supported on the hard-to-reduce oxides, these catalysts showed nanometric dimensions. The catalysts were used for the growth of multi-walled carbon nanotubes by the chemical vapor deposition method. The syntheses were conducted under ethylene - argon atmosphere at 700°C. The obtained catalysts and carbon materials after the synthesis were characterized using transmission electron microscopy (TEM), X-ray diffraction method (XRD), Raman spectroscopy and thermogravimetric analysis (TG). The effect of the kind of catalyst on the properties of the obtained carbon material has been described.

Synthesis, properties and applications of CMK-3-type ordered mesoporous carbons

86%

Olchowski R., Dobrowolski R.

Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia

2018

vol. 73

issue 1

For the last two decades the CMK-3-type carbon was the subject of study by researchers from all over the world for wide range of applications: adsorptive, catalytic, magnetic and electric. Changing of modification strategies resulted in obtaining carbonaceous materials with interesting properties. In this review the synthesis, properties and applications of the CMK-3-type nanocarbon are described.

Phenol oxidation with hydrogen peroxide using Cu/ZSM5 and Cu/Y5 catalysts

86%

Valkaj K., Wittine O., Margeta K., Granato T., Katović A., Zrnčević S.

In this work, catalytic activity and stability of Cu/Y5 and Cu/ZSM5 zeolites in phenol oxidation with hydrogen peroxide were examined. The catalyst samples were prepared by the ion exchange method of the protonic form of commercial zeolites. The catalysts were characterized by the powder X-ray diffraction (XRD), AAS, while the adsorption techniques were used to measure the specific surface area.The thermal programmed desorption of NH3 (NH3-TPD) was used for measuring the total number of acid sites formed on the surface of zeolites.Catalytic performance of the prepared samples was monitored in terms of phenol, hydrogen peroxide and total organic carbon (TOC) conversion, by-product distribution and a degree of copper leached into the aqueous solution.It was found that the activity of Cu/Y5 catalyst was generally higher than that of Cu/ZSM5 and that unlike Cu/ZSM5, Cu/Y5 catalyzed phenol oxidation more completely.

Refine search results

2 Polish Journal of Chemical Technology

1 Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia

1 2018

1 2014

1 2011

1 Dobrowolski R.

1 Granato T.

1 Jędrzejewska A.

1 Kaczmarek A.

1 Katović A.

1 Margeta K.

1 Narkiewicz U.

1 Olchowski R.

1 Pełech I.

1 Valkaj K.

1 Wittine O.

1 Zrnčević S.

Search results

Preparation and characterization of multi-walled carbon nanotubes grown on transition metal catalysts

Synthesis, properties and applications of CMK-3-type ordered mesoporous carbons

Phenol oxidation with hydrogen peroxide using Cu/ZSM5 and Cu/Y5 catalysts