Production of CeO2/NiO and CeO2/NiO-Pt Nanocomposites by EPM

V. Serga, A. Cvetkovs, A. Krumina, S. Chornaja, J. Kunakovs, M. Maiorov

Nanocomposites CeO₂/5wt.% NiO, CeO₂/Pt and CeO₂/5wt.% NiO-Pt with different Pt loading were produced by the extractive-pyrolytic method (EPM) and characterized by XRD and SEM. NiO and Pt were deposited on a carrier (CeO₂ nanopowder) by thermal decomposition of nickel hexanoate and n-trioctylammonium hexachloroplatinate, respectively. XRD analysis showed that in CeO₂/5wt.% NiO nanocomposites the mean size of nickel oxide crystallites increases (from amorphous to 18 nm) when the pyrolysis temperature increases from 300 ºC to 700 ºC. In CeO₂/ Pt nanocomposites with the Pt content from 0.3 wt.% to 2.4 wt.%, both with NiO and without it, the Pt particles are X-ray amorphous. With a higher metal content (4.8 wt.%) in CeO₂/NiO-Pt composites, the mean size of Pt crystallites was 4 nm that is twice less if compared with the CeO₂/Pt composite. The produced nanocomposites were tested in glycerol oxidation processes by molecular oxygen. It has been found that CeO₂/Pt and CeO₂/5 wt.% NiO-Pt composites are catalytically active in alkaline glycerol water solutions. It was shown that the Pt weight loading (0.3 – 1.2 %) in the composites significantly affected the glycerol conversion (12 – 68 %). The main product of oxidation was glyceric acid.