Deposition of NiO on 3 mol% yttria-stabilized zirconia and Sr0.96Y0.04TiO3 materials by impregnation method

The main purpose of this work was the synthesis of composite materials by deposition of nickel oxide on 3 mol% yttria-stabilized zirconia (3 mol% Y2O3–97 mol% ZrO2–YSZ) and Sr0.96Y0.04TiO3 (4 mol% Y-doped strontium titanate—SYTO) supports. Yttria-stabilized zirconia and yttrium-doped strontium titanate were obtained by modified citrate method. The deposition of nickel oxide was performed by impregnation method. All materials were impregnated with proper amount of nickel(II) nitrate aqueous solution to receive the 1 and 5 mass% of nickel in the final composite. The temperature-programmed reduction (TPR) was applied to analyze the reduction mechanism of deposited NiO. Three forms of nickel oxide: non-stoichiometric NiO1+x, hexagonal and cubic are postulated on the base of the TPR profiles and analysis of bonds length in nickel oxides structures. Moreover, TPR analysis shows that support strongly affects the reduction mechanism as a consequence of various interactions between NiO and YSZ/SYTO. In the case of YSZ, the nickel oxide reveals the tendency to deposit on the support surface, while using SYTO as the support, nickel oxide exhibits significant ability to react with doped strontium titanate and what is more important nickel incorporates into Sr0.96Y0.04TiO3 structure.