The nanostructured CexZr1-xO2 systems (0 ≤ x ≤ 0.75) were prepared combining alkoxide and nitrate precursors in an ethanol/water mixture by the continuous supercritical solvothermal solgel like synthesis. They were subsequently used as supports for nickel impregnation (10 wt.%) to obtain catalysts for dry reforming of methane (DRM) reaction. A reference CexZr1-xO2 (x = 0.50) system prepared via conventional coprecipitation method was used as a support for nickel impregnation in the comparative study of the nanostructured materials' catalytic potential. The morphological and structural properties of the prepared nanostructured supports and Nicontaining catalysts were investigated by numerous techniques as XRD, Raman spectroscopy, SEM, TEM, EDS, chemisorption and others. The conditions of DRM reaction were chosen in order to compare the activity, the stability as well as the selectivity of coke formation in the presence of the prepared catalytic materials. It was found that the industrial catalyst leads to heavy coking in the chosen conditions with a rapid loss of activity. While the nanostructured CexZr1-xO2 (0 ≤ x ≤ 0.75) materials are found to be promising supports for Ni dispersion and coke control in DRM. In this study the nanostructured Ce0.50Zr0.50O2 material impregnated with nickel shown the highest TOF and the smallest selectivity of coke formation in DRM among other nanostructured materials. The continuous supercritical solvothermal method allows to prepare nanostructured mixed oxides materials that could be promising supports for different active metals dispersion and for coke control in the reactions where coking may be abundant.

Positive environmental and technological contexts make dry methane reforming (DMR) an extensively studied reaction. During this process two main greenhouse gases CH4 and CO2 can be simultaneously converted into syngas – a mixture of CO and H2. Supported-nickel is one of the most frequently applied DMR catalysts. Their activity depends mainly on Ni concentration, kind of its precursor and a deposition method. As DMR is a demanding high-temperature reaction, it requires not only an active but first a very stable catalyst. Structural, textural and functional properties of such support remain thus of crucial efficiency. Main aim of this work was to elucidate how the synthesis of CeO2-ZrO2 support obtained by supercritical fluid method (i.e. at temperature of 400°C under a pressure of 25 MPa), can influence the properties of Ni-based DMR catalysts. The supports of various compositions (CeO2 content from 100 to 0 %), subsequently calcined at 800°C for 6h in air have been analyzed. Nickel was deposited from nitrate(V) precursor via classical wet impregnation. The final catalysts have been characterized structurally (XRD, RS), texturally (BET, SEM) and functionally (UV/Vis-DR, XPS). Catalytic tests in dry methane reforming reaction have been performed to determine activity and stability of the synthesized samples.