Rare-earth orthoferrites have found wide application in thermocatalytic reduction-oxidation processes. Much less attention has been paid, however, to the production of CeFeO3, as well as to the study of its physicochemical and catalytic properties, in particular, in the promising process of CO2 utilization by hydrogenation to CO and hydrocarbons. This study presents the results of a study on the synthesis of CeFeO3 by solution combustion synthesis (SCS) using various fuels, fuel-to-oxidizer ratios, and additives. The SCS products were characterized by XRD, FTIR, N2-physisorption, SEM, DTA–TGA, and H2-TPR. It has been established that glycine provides the best yield of CeFeO3, while the addition of NH4NO3 promotes an increase in the amount of CeFeO3 by 7–12 wt%. In addition, the synthesis of CeFeO3 with the participation of NH4NO3 makes it possible to surpass the activity of the CeO2–Fe2O3 system at low temperatures (300–400 °C), as well as to increase selectivity to hydrocarbons. The observed effects are due to the increased gas evolution and ejection of reactive FeOx nanoparticles on the surface of crystallites, and an increase in the surface defects. CeFeO3 obtained in this study allows for achieving higher CO2 conversion compared to LaFeO3 at 600 °C.

Glycerol is a promising raw material for obtaining various chemicals and fuels, including H2. Nevertheless, development of cost-effective and stable catalysts with high activity and selectivity for H2 production from...

The grainy and porous ZnO powders were synthesized by thermal decomposition of zinc nitrate and polymer-salt method. The comparative study of the crystal structure, morphology, luminescence, adsorptive and photocatalytic properties of ZnO powders was carried out. The addition of PVP in initial aqueous solutions of zinc nitrate determines the remarkable change of powder morphology and decreases the average size of ZnO nanocrystals. Luminescence spectra in the visible spectral range indicate the significant difference of structural defects types in grainy and porous powders. Porous powders demonstrate high ability for singlet oxygen photogeneration and photocatalytic properties. The kinetics of diazo dye adsorption on both powders is described successfully by the kinetic equation of pseudo-second order. Kinetic dependencies of photocatalytic oxidation of Chicago Sky Blue diazo dye using as grain ZnO powder so as porous ZnO powders are described by the Langmuir–Hinshelwood model but process rates are different. Porous ZnO powder demonstrates strong ability for photogeneration of singlet oxygen under visible irradiation and high photocatalytic properties (rate constant 0.042 min−1).

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