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This paper is devoted to the study of active and stable nickel catalysts for methane dry reforming based on Pr-doped ceria–zirconia obtained via the solvothermal continuous method. Studies on the physicochemical and catalytic properties of the 5%Ni/Ce0.75Zr0.25−xPrxO2 series have showed that Pr introduction leads to an increase in the amount of highly reactive oxygen in the oxide lattice. Praseodymium-based catalysts showed significantly higher reactant conversions. In addition to the nature of support, the method of nickel introduction was also studied; Ni was added both using impregnation and the one-pot procedure with mixed oxide preparation. The method of Ni addition was shown to have significant effect on the morphology of its particles and Ni-support interaction, and, respectively, on catalytic activity and coking stability. The 5%Ni/Ce0.75Zr0.15Pr0.1O2 catalyst prepared by one-pot method showed stable operation in the MDR reaction for 30 h at CO2 and CH4 conversions of ~40% and an H2 yield of ~18% (T = 700 °C, τ = 10 ms).

This review considers problems related to design of efficient structured catalysts for natural gas and biofuels transformation into syngas. Their active components are comprised of fluorite, perovskite and spinel oxides or their nanocomposites (both bulk and supported on high surface area Mg-doped alumina or MgAl2O4) promoted by platinum group metals, nickel and their alloys. A complex of modern structural, spectroscopic and kinetic methods was applied to elucidate atomic-scale factors controlling their performance and stability to coking, such as dispersion of metals/alloys, strong metal-support interaction and oxygen mobility/reactivity as dependent upon their composition and synthesis procedures. Monolithic catalysts comprised of optimized active components loaded on structured substrates with a high thermal conductivity demonstrated high activity and stability to coking in processes of natural gas and biofuels reforming into syngas. A pilot-scale axial reactor equipped with the internal heat exchanger and such catalysts allowed to efficiently convert into syngas the mixture of natural gas, air and liquid biofuels in the autothermal reforming mode at low (~50–100 °C) inlet temperatures and GHSV up to 40,000 h−1.

The Ni-containing catalysts based on ceria–zirconia doped with Ti and Ti+Nb were prepared by the solvothermal method in supercritical fluids. Ni deposition was carried out by incipient wetness impregnation and the one-pot technique. All materials were investigated by a complex of physicochemical methods (XRD, BET, TEM, H2-TPR). Samples catalytic properties were studied in methane dry reforming in the plug-flow reactor. Conversions of CH4 and CO2, H2/CO ratio, and CO and H2 yields were measured, and detailed kinetics analysis was carried out. The influence of Ni loading method and support modification on the catalytic behavior in the methane dry reforming process was studied. The preparation method of catalysts affects the textural characteristics. For one-pot samples, pore volume and surface area are lower than for impregnated samples. For catalysts on modified supports, strong metal–support interaction was shown to increase catalytic activity. A reduction pretreatment of samples was shown to have significant influence on their catalytic properties. The kinetic parameters such as reaction rate constant at 700 °C, effective activation energy, and TOF were estimated and analyzed.

To achieve a high activity and coking stability of nickel catalysts in dry reforming of methane, materials comprised of ceria–zirconia doped by Ti were investigated as supports. Ceria–zirconia supports doped with titanium were prepared either via the Pechini method or by synthesis in supercritical alcohol media. Ni-containing catalysts were prepared by two techniques: standard incipient wetness impregnation and one-pot synthesis. The catalytic reaction of DRM to synthesis gas was carried out in the 600–750 °C range over 5% wt. Ni/Ce(Ti)ZrO2. Dried and calcined supports and catalysts were characterized by physicochemical methods including N2 adsorption, XRD, Raman, H2-TPR, and HRTEM. Both preparation methods led to formation of solid solution with cubic fluorite-like structure, as well as after addition of Ti. Introduction of Ti should provide improved oxygen storage capacity and mobility of support oxygen. The highest activity was observed with the catalyst of 5% wt. Ni/Ce0.75Ti0.2Zr0.05O2−δ composition due to optimized oxide support structure and support oxygen mobility.