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.

The catalytic performance of iron-based nanodispersions in Fischer–Tropsch synthesis in two different slurry reactor types, specifically a continuous stirred-tank reactor (CSTR) and a slurry bubble column reactor (SBCR), was comparatively investigated. It was found that, at equal process temperatures, the CO conversion in the SBCR using a gas disperser with four equally spaced 1-mm holes was lower than that in the CSTR. However, this observation is inconsistent with other reports in the literature. Replacing this disperser with a plate with a single centered 2-mm hole enhanced the CO conversion up to values close to those obtained in the CSTR. The reaction rate constants were calculated for the different reactor types.

The catalytic activity of an iron–containing nanoscale chitosan-based catalyst in the Fischer–Tropsch synthesis (FTS) and the features of the formation of the structure of such a catalyst have been studied. It is shown that the nature of the acids used in the preparation stage—nitric, acetic or citric, has a significant effect on the structure obtained by partial destruction of chitosan and the size of the nanocrystallites of the active phase, which, in turn, leads to significant changes in the activity of the catalyst and productivity for the target products—C₅₊ hydrocarbons. The best performance of catalyst in FTS observed for the sample, obtained with use of nitric acid: С₅₊ productivity reached to 2136 g С₅₊/kgFe/h.

The method of obtaining functional materials almost always influences the physicochemical properties of the resulting substances. The plasma treatment of solid materials is considered to be a more energy efficient method when compared with thermal destruction. Our work is the first to treat double complex salt (DCS) [Co(NH₃)₆][Fe(CN)₆] with different plasma discharge modes. We have demonstrated the possibility of obtaining a single-phase spinel with a CoFe₂O₄ structure as a result of the calcination in air of the plasma destruction product. The crystallite sizes of the obtained spinel are 40 nm, with a lattice constant 8.38 Å.

For the first time, the study systematically investigates, the effects of the partial pressures of CO and H₂ on Fischer–Tropsch performance in a slurry bubble column reactor (SBCR) over an iron-based nanodispersion. It is shown that, over the tested temperature range, both decreasing CO partial pressure and increasing H₂ partial pressure enhance CO conversion. At CO/H₂ molar ratios of 1 : 1.5 to 1 : 2, reactor pressures of 1.9–2.2 MPa, and temperatures of 240–300°C, methane and C₂–C₄ hydrocarbons are selectively produced. On the other hand, at CO/H₂ = 1 : 1, 1.5–2.0 MPa, and 280–300°C, the predominant products were C₅₊ hydrocarbons. The CO/H₂ molar ratios of 1 : 1 to 1 : 2, 1.5–2.2 MPa, and 240–260°C are the optimal reaction conditions to maximize the selectivity towards oxygenates. The XRD data for the spent catalysts corroborate the correlations identified during the catalytic test.

Hydrogenation of CO2 over Biochar-Supported Catalysts Реакция гидрирования co 2 на катализаторах на основе биоугля