This review provides an analysis of recent scientific and engineering literature on chemical methods for CO₂ processing using heterogeneous catalysts. The following major uses of carbon dioxide are discussed: exhaustive hydrogenation; synthesis of hydrocarbons including light olefins; synthesis of oxygenates; and production of cyclic carbonates. Furthermore, the paper highlights the main design approaches for CO₂ conversion catalysts and formulates priorities for decarbonization using heterogeneous catalytic reactions.

The study investigates hydrogenation of CO ₂ over mono- and bimetallic catalysts supported on biochar. In this reaction, bimetallic iron–cobalt catalysts were shown to surpass monometallic iron and cobalt catalysts in terms of catalytic performance. The optimal combination of performance parameters was reached at an iron to cobalt ratio of 3 : 1. The composition and genesis of the active phase in the bimetallic Fe–Co catalyst were identified, and the CO ₂ hydrogenation mechanism was suggested for an iron-dominated bimetallic catalyst. Using biochar as a support was found to provide an active phase composition favorable for CO ₂ hydrogenation.

Reducing the amount of CO₂ in the atmosphere is a very important task. Therefore, the development and search for new approaches to the synthesis of catalytic systems, allowing for the catalytic conversion of CO₂ into valuable products, is an urgent task. In this work, the catalyst was obtained by the thermolysis of a double complex compound. In this regard, kinetic studies of the parameters of the thermolysis process of double complex salts-[Co(NH)₃]₆][Fe(CN)₆] were additionally determined using isoconversion and model approaches of non-isothermal kinetics. The catalyst was studied using various physicochemical methods—X-ray diffraction (XRD), infrared (IR)-spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). It was shown that, at the stage of catalyst preparation, the formation of a CoFe alloy occurred, while the surface mainly consisted of carbon in sp₂-hybridization, and the metals existed in the form of spinel CoFe₂O₄. It was shown that catalysts based on bimetallic salts were active in the process of hydrogenation of carbon dioxide without a pre-activation stage (CO₂ conversion reached 28%, with a specific activity of 4.0 µmolCO₂/gMe·s). It was established that it was possible to change the selectivity of the carbon dioxide hydrogenation process by pre-treating the catalyst with hydrogen (selectivity for methane formation in the presence of an unreduced catalyst is 46.4–68.0%, whereas in the presence of a reduced catalyst it is 5.1–16.5%).

Supported iron catalysts based on a carbon-containing material, biochar obtained by the hydrothermal carbonization of biopolymers (cellulose and lignin), w

Targeted synthesis of C/composite Ni-based material was carried out by the method of matrix isolation. The composite was formed with regard to the features of the reaction of catalytic decomposition of methane. The morphology and physicochemical properties of these materials have been characterized using a number of methods: elemental analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, temperature programmed reduction (TPR-H₂), specific surface areas (SSA), thermogravimetric analysis, and differential scanning calorimetry (TGA/DSC). It was shown by FTIR spectroscopy that nickel ions are immobilized on the polymer molecule of polyvinyl alcohol, and during heat treatment, polycondensation sites are formed on the surface of the polymer molecule. By the method of Raman spectroscopy, it was shown that already at a temperature of 250 °C, a developed conjugation system with sp2-hybridized carbon atoms begins to form. The SSA method shows that the formation of the composite material resulted in a matrix with a developed specific surface area of 20 to 214 m²/g. The XRD method shows that nanoparticles are essentially characterized by Ni, NiO reflexes. The composite material was established by microscopy methods to be a layered structure with uniformly distributed nickel-containing particles 5–10 nm in size. The XPS method determined that metallic nickel was present on the surface of the material. A high specific activity was found in the process of catalytic decomposition of methane—from 0.9 to 1.4 g_H2/g_cat/h, X_CH4, from 33 to 45% at a reaction temperature of 750 °C without the stage of catalyst preliminary activation. During the reaction, the formation of multi-walled carbon nanotubes occurs.