Search results

Search:
in the keywords: Citrate method

Sort By:

Limit search:

Characterization of the citrate precursor, used for synthesis of nanosized Mg-Zn ferrites

100%

Kassabova-Zhetcheva V.

Open Chemistry

2009

vol. 7

issue 3

415-422

The citrate precursor has been used to synthesize nanocrystalline Mg-Zn-ferrites. The nature of the prepared precursor is characterized and compared with those of the precursors studied earlier, prepared by the same process. The study has been performed by inorganic and organic elemental analyses, Fourier Transformed Infrared Spectroscopy (FTIR), Mössbauer spectroscopy, X-ray Photoelectron Spectroscopy (XPS), Electron Paramagnetic Resonance (EPR), Electronic absorption spectrometry in the UV-VIS region, Differential Thermal analysis/ Thermogravimetry (DTA-TG) analyses, and X-ray diffraction (XRD) analysis. The collected results determined the precursor as a coordination polymer with monomer unit (NH4)4{M [Fe(C6H5O7)2]2}, where M=Zn or Mg. [...]

AlZn based Co and Ni catalysts for the partial oxidation of bioethanol - influence of different synthesis procedures

88%

Ehrich H., Kraleva E.

Open Chemistry

2014

vol. 12

issue 12

1285-1293

The catalytic performance of Co and Ni catalysts on AlZn mixed oxide supports depends on the synthesis procedure used for their preparation. For this study CoAlZn and NiAlZn catalysts were prepared by conventional sol-gel synthesis of the mixed oxide and subsequent impregnation of the support with the transition metal (SG = sol gel method) as well as by a single-step method were a gel is formed based on salts of all components using citric acid as chelating agent (CM = citrate method). The structure and morphology of the catalysts were characterized by nitrogen sorption, XRD and TPR measurements. They showed high activity in the partial oxidation of ethanol at 600–750 °C, but their properties depend on the preparation method. The higher performance of the catalysts prepared by the citrate method, where the transition metal is incorporated into the crystal structure of the support during preparation, is based on a change in morphology and structure, resulting in more active sites exposed on the surface. Compared to the Co catalysts, Ni catalysts showed a higher performance. This might be due to the higher reducibility and the smaller Ni particles size, which allows a better interaction with the support in NiAlZn catalysts.

Refine search results

2 Open Chemistry

1 2014

1 2009

1 Ehrich H.

1 Kassabova-Zhetcheva V.

1 Kraleva E.

Search results

Characterization of the citrate precursor, used for synthesis of nanosized Mg-Zn ferrites

AlZn based Co and Ni catalysts for the partial oxidation of bioethanol - influence of different synthesis procedures