Mechanochemically assisted solid state synthesis, characterization, and catalytic properties of MgWO4
2015
Gancheva, Maria | Naydenov, Anton | Iordanova, Reni | Nihtianova, Diana | Stefanov, Plamen
The synthesis of MgWO₄nanopowders was achieved by mechanically activated and following thermal treatment at 850 °C of two mixtures, containing the pure oxides (MgO/WO₃) and magnesium carbonate trihydrate and tungsten oxide (MgCO₃·3H₂O/WO₃) as precursors. The obtained samples have been analyzed by the X-ray powder diffraction, infrared spectroscopy (IR), thermal analysis, specific surface area, transmission electron microscopy (TEM, SAED, and XEDS), and X-ray photoelectron spectroscopy. The prepared samples were modified with 0.5 wt% Pd, and the catalytic activities have been measured in reaction of complete oxidation of CO, methane, n-hexane, and toluene. It has been observed that Pd-containing samples with 3 wt% WO₃are more active than the MgWO₄/Pd, the most remarkable improvement being achieved in the reaction of toluene combustion. This result is explained by the presence of the palladium in Pd⁴⁺state (as PdO₂particles) due to the stabilization role of the WO₃-matrix.
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