Сверхкритические флюиды. Теория и практика
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2019, N2, pp. 105-115

A.Yu. Nikolaev, V.E. Sizov, S.S. Abramchuk, M.O. Gallyamov

Formation of Dispersed Particles of Tungsten Oxide and Deposition of Platinum Nanoparticles on Them Using Organometallic Precursors From Solutions in Supercritical Carbon Dioxide

A one-pot synthesis of dispersed platinum-tungsten composites was developed. Initially, using tungsten hexacarbonyl as a precursor in solution in supercritical CO2 in the presence of oxygen as an oxidizer promoting thermal decomposition of the precursor, dispersed particles of tungsten oxide with a grain size of about 100 nm and an aggregate size of 200–500 nm were synthesized. Then, these dispersed particles were used as a substrate for the subsequent deposition of platinum nanoparticles, which included two stages: 1) forming a film of an organometallic precursor by deposition from a solution in supercritical CO2 and 2) thermal decomposition of the precursor. As the two types of platinum precursors, the dimethyl(1,5-cyclooctadiene)platinum and platinum hexafluoroacetylacetonate, which both are soluble in sc CO2, were used as the typical ones in the practice of similar studies. The size of the formed platinum nanoparticles was 2.3 ± 0,7 nm using the former precursor and 3.5 ± 0,8 nm using the latter. The obtained composites are characterized by a relatively narrow size distribution of the noble metal nanoparticles and their uniform distribution over the surface of the particles of the dispersed carrier. Such materials may be of interest for (electro)catalysis tasks.

Key words: supercritical carbon dioxide, dispersed tungsten oxides, platinum nanoparticles, organometallic precursors, electron microscopy

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