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In this work, we studied the role of zinc in the composition of supported iron-containing catalysts for the hydrogenation of CO 2 . Various variants of incipient wetness impregnation of the support were tested to obtain catalyst samples. The best results are shown for samples synthesized by co-impregnation of the support with a common solution of iron and zinc precursors at the same molar ratio of iron and zinc. Catalyst samples were analyzed by various methods: Raman, DRIFT-CO, TPR-H 2 , XPS, and UV/Vis. The introduction of zinc leads to the formation of a mixed ZnFe 2 O 4 phase. In this case, the activation of the catalyst proceeds through the stage of formation of the metastable wustite phase FeO. The formation of this wustite phase promotes the formation of metallic iron in the composition of the catalyst under the reaction conditions. It is believed that the presence of metallic iron is a necessary step in the formation of iron carbides-that is, active centers for the formation and growth of chain in the hydrocarbons. This leads to an increase in the activity and selectivity of the formation of hydrocarbons in the process of CO 2 hydrogenation.

The nonoxidative conversion of ethanol to acetaldehyde under thermal and microwave heating was studied on mixed oxide ZnO-CuO-SiO 2 catalysts modified with additives of tungsten carbide nanoparticles. The results revealed that the WC-modified catalyst exhibited superior activity and selectivity under microwave heating conditions. It is assumed that when microwave heating is used, hot zones can appear at the contact points of WC nanoparticles and active centers of the mixed oxide ZnO-CuO-SiO 2 catalyst, which intensively absorb microwave energy, allowing the more efficient formation of acetaldehyde at moderate temperatures. Thermodynamic calculations of equilibrium concentrations of reagents and products allowed us to identify the optimal conditions for effective acetaldehyde production. The initial catalyst and the catalyst prepared by the coprecipitation of the oxides with the addition of WC were characterized by physicochemical methods (TPR-H 2 , XRD, DRIFTS of adsorbed CO). The active centers of the oxide catalyst can be Cu + cations.

The paper presents the results obtained in studying glycerol hydrogenolysis into 1-propanol and 2-propanol over bifunctional Ni/WO 3 -TiO 2 and Ni/WO 3 -ZrO 2 catalysts in the flow system. Due to the optimal combination of acidic and hydrogenation properties of the heterogeneous catalysts, they exhibit higher performance in glycerol conversion into C 3 alcohols, although the process is carried out in rather mild conditions. At the reaction temperature of 250 °C and hydrogen pressure of 3 MPa, the total yield of 1-propanol and 2-propanol reaches 95%, and the glycerol conversion is close to 100%.