Open Access
Access granted
Subscription Access
Vol 66, No 3 (2025)
ОБЗОР
Ceria-supported platinum water gas shift catalysts: composition, structure, reaction mechanism
Abstract
Water gas shift is an industrially important reaction included in the process chain for producing pure hydrogen from methane or other hydrocarbon feedstocks. The relevance of the process has increased with the invention of modern fuel cells, which require high-purity hydrogen for power. The need to develop hydrogen infrastructure and, at the same time, the difficulties of transporting this gas have stimulated the search for catalysts that are convenient and effective for hydrogen production and purification in compact mobile units. For water gas shift reaction, noble metal catalysts are considered as possible options. This article presents a review of studies devoted to platinum catalysts supported on ceria and its doped forms for the water gas shift reaction. The influence of the oxide support composition on the catalytic properties of such systems is considered, variants of the reaction mechanism and active site structure are presented, and the results of studies of bimetallic Pt-containing and structured catalysts are summarized.
Kinetics and Catalysis. 2025;66(3):149-165
149-165
ARTICLES
Study of deactivation of Mg-containing zeolite catalyst in propane conversion into olefinic hydrocarbons
Abstract
The process of deactivation of magnesium-containing zeolite in three interregeneration cycles of operation during the conversion of propane into olefin hydrocarbons has been studied. The main factors leading to a decrease in the activity and selectivity of the catalyst have been identified. The distribution and state of active components in the catalytic system before and after the reaction, as well as after oxidative regeneration of the catalyst have been investigated. The nature and amount of carbon deposits formed on the catalyst under study during the reaction have been established, and their absence after its regeneration has been proven.
Kinetics and Catalysis. 2025;66(3):166-176
166-176
Effect of the nature of alkali metal on the activity of carbon nanofibers in the catalytic decomposition of formic acid
Abstract
The catalytic activity of carbon nanofibers modified by alkali metals in the reaction of formic acid decomposition has been studied. It was found that the catalytic activity increases in the sequence: 4% LiOH/CNF, 4% NaOH/CNF, 4% KOH/CNF, that is, the higher the basicity of the alkali metal, the higher the catalyst activity. The nature of the alkali metal has little effect on the selectivity in the reaction of formic acid decomposition on CNF. It is mainly the dehydrogenation reaction of formic acid with the formation of H2 and CO2. In the case of KOH/CNF catalysts it is shown by a number of physical methods of investigation that alkaline treatment leads to modification of the CNF surface by potassium ions, which are uniformly distributed on the carbon surface in the form of functional groups; in addition, nanoparticles of potassium hydrogen carbonate are present at an increased content of applied potassium hydroxide.
Kinetics and Catalysis. 2025;66(3):177-188
177-188
XPS STUDY OF DIFFERENCES IN STABILITY OF MWCNTS AND N-MWCNTS AS A SUPPORT FOR MODEL SILVER CATALYST FOR ETHYLENE EPOXIDATION
Abstract
The effect of preparation conditions on the stability of N-MWCNT samples prepared under oxygen-free conditions by the method of catalytic gas-phase decomposition of ethylene at 680°C on the Fe2Co/Al2O3 catalyst in the presence of NH3, with respect to atmospheric oxygen was studied by the XPS method. The analysis of the oxygen and nitrogen contents in the N-MWCNT composition, as well as the shape of the C1s XPS line after sample removal from the reactor in the air depending on the volume fraction of ammonia in the reaction mixture, as well as after treatment in nitric acid indicates that at low NH3 contents (2–4 vol. %) the incorporation of nitrogen into the structure of nanotubes leads to an increase in the structure ordering / a decrease in disorder, as a result, the oxygen content in these samples is minimal. Comparison of the supported catalysts Ag/MWCNT-0n and Ag/N-MWCNT-4n shows that the introduction of nitrogen during the support synthesis allows not only to decrease the oxygen content in carbon nanotubes, but also to increase the oxidation stability of both the support itself and the silver catalyst based on it.
Kinetics and Catalysis. 2025;66(3):189-203
189-203
Low-temperature O3-catalytic oxidation of VOC’s on a bifunctional Cо–W/Al2O3 catalyst
Abstract
The characteristics of the bifunctional Co–W catalyst based on Al2O3 in the processes of ozone decomposition and ozone-catalytic oxidation (OZCO) of n-butane were studied. The data obtained allow us to conclude that the loading of 1 wt.% Co on 8% W/Al2O3 leads to a significant improvement of n-C4H10 conversion as compared to the reference samples 8% W/Al2O3 and 1% Co/Al2O3. The increase in activity is achieved due to the synergistic interaction between of Co (ozone decomposition sites), and W (hydrocarbon activation sites).
Kinetics and Catalysis. 2025;66(3):204-208
204-208
Effect of migration of nickel of carbon nanofiber support into active phase of molibdenum disulfide based catalyst of alcohol synthesis
Abstract
Fibrous carbon produced by catalitic decomposition of methane and containing minor amount of Ni was tested as a support for molybdenum disulfide-based catalysts for reductive conversion of CO into alcohols. It was established for the first time using method of X-ray difraction, transmission and scanning microscopy that during sulfidation of catalyst precursor nickel, incapsulated in carbon, intgrates into layered molybdenum disulfide cristallites, becoming part of the catalytically active Ni–(Co)–Mo–S phase.
Kinetics and Catalysis. 2025;66(3):209-224
209-224
Interaction of ethanol with the surface of nickel supported catalysts as determined by in situ IR-spectroscopy
Abstract
The application of IR spectroscopy in situ enabled the identification of ethoxy groups, acetate complexes, and complex products on the surface of nickel supported catalysts during the ethanol decomposition reaction in the range of 250–325°C. Ethoxy groups are formed according to the classical scheme with the participation of hydroxyl groups of the surface and are localized along the boundaries of metal clusters. The source of formation of acetate complexes are ethoxy groups. Complex surface compounds formed due to the condensation reaction of CH2 groups prevent surface carbonization. Surface complexes activated by adsorption diffuse onto metal clusters, where they undergo further transformations. The dependence of the concentration of ethoxy groups on time under ethanol conversion conditions is not processed in either first- or second-order coordinates. Apparently, ethoxy groups are involved in several surface reactions. The intensity dependence of the absorption band of acetates is processed in the coordinates of the first-order equation.
Kinetics and Catalysis. 2025;66(3):225-234
225-234
NI-CONTAINING GLASS-FIBER CATALYST FOR HYDROGENOLYSIS OF LIGHT PARAFFINS: RELATIONSHIP BETWEEN ACTIVITY AND CATALYST PREPARATION CONDITIONS
Abstract
This study evaluates the efficiency of nickel-containing structured glass-fiber catalysts prepared by two different methods for the hydrogenolysis of saturated hydrocarbons, including propane, butane, and pentane. he dependence of the crystallite size and dispersion of the catalyst’s active component (AC) on the preparation method and reduction temperature conditions was established. Impulse surface thermosynthesis (ISTS) facilitates the most uniform distribution of the AC over the support surface and its higher dispersion. The crystallite size is primarily determined by the reduction temperature of the AC. The GFC containing ~10 wt % nickel, prepared by the ISTS method and reduced at the minimum temperature of 300°C, demonstrated the highest catalytic activity. Compared to a commercial nickel catalyst, the Ni/GFC samples exhibited tens of times higher specific catalytic activity per unit mass of nickel. Nickel-containing GFCs synthesized by the ISTS method are highly promising for use in advanced catalytic technologies for paraffin hydrogenolysis, particularly for processing gas condensate into methane.
Kinetics and Catalysis. 2025;66(3):235-248
235-248