Kinetics and Catalysis最新文献

{"title":"Structural Features of Aluminates Ln(Ca)AlO3 (Ln = La, Ce, Pr) and Their Catalytic Properties in Methane Oxidation","authors":"P. R. Vasyutin,&nbsp;M. Yu. Sinev,&nbsp;E. Yu. Lyubimov,&nbsp;Yu. A. Gordienko,&nbsp;M. A. Panafidin,&nbsp;A. V. Bukhtiyarov,&nbsp;I. P. Prosvirin","doi":"10.1134/S0023158425601172","DOIUrl":"10.1134/S0023158425601172","url":null,"abstract":"<p>The structural features and some properties of aluminates of the composition LnAlO₃ (Ln = La, Ce, Pr) are studied. All three aluminates obtained at the final calcination temperature of 900°C have a cubic perovskite structure. In Ce-containing systems, along with it, a highly dispersed CeO₂ phase with a cubic fluorite structure is observed. The cubic perovskite structure is retained upon modification of La and Pr aluminates by substituting 10 at % of Ln³⁺ ions with Ca²⁺ ions; in this case, the unit cell parameter decreases due to the smaller radius of the Ca²⁺ ion compared to Ln³⁺, which indicates isomorphic substitution of Ln³⁺ → Ca²⁺. The catalytic properties of the obtained systems in high-temperature oxidation of methane were studied. The analysis of the relationship between the surface properties studied by X-ray photoelectron spectroscopy and the catalytic properties of La and Pr aluminates allows us to conclude that point defects (presumably O^– oxygen radical ions) participate in the production of C₂ hydrocarbons, a process called oxidative coupling of methane (OCM). In the case of praseodymium aluminate, this mechanism is supplemented by a redox cycle occurring due to the oxidation-reduction of praseodymium ions (Pr³⁺ ⇌ Pr⁴⁺) on the surface of the samples. As a result, samples of similar composition (not modified and equally modified with calcium) based on praseodymium aluminate are significantly more effective as catalysts for the OCM process. Ce-containing samples are unstable under methane oxidation conditions; they decompose with the release of the CeO₂ phase and have very low selectivity for C₂ hydrocarbons. The conditions for a correct comparison of the efficiency of oxide catalysts for the OCM process are determined.</p>","PeriodicalId":682,"journal":{"name":"Kinetics and Catalysis","volume":"66 6","pages":"682 - 699"},"PeriodicalIF":1.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147579284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nature of Nickel(II) Compounds Formed upon Interaction of an Amine–Imine Ni(II) Complex with MAO and AlMe3 According to In Situ NMR Data","authors":"I. E. Soshnikov,&nbsp;E. P. Talsi","doi":"10.1134/S0023158425600701","DOIUrl":"10.1134/S0023158425600701","url":null,"abstract":"<p>The mechanism of catalytic action of α-diimine nickel complexes, one of the most widely used post-metallocene catalysts for ethylene polymerization, remains the subject of extensive discussion. It is generally recognized that so-called “cationic” Ni(II) complexes play a key role in the catalytic cycle, serving as the sites where chain initiation, branching, and chain growth occur. However, most of these highly unstable complexes have been detected in model systems, whereas very limited information is available on nickel(II) complexes present in real catalytic systems. In this work, the nature of intermediates formed during the activation of nickel(II) complexes bearing neutral N,N'-donor amine–imine ligands, related to classical α-diimine complexes, by commonly used cocatalysts was studied using in situ NMR spectroscopy. It was established that unstable “cationic” Ni(II) complexes are also formed in these systems and act as direct precursors of the active catalytic sites.</p>","PeriodicalId":682,"journal":{"name":"Kinetics and Catalysis","volume":"66 6","pages":"744 - 752"},"PeriodicalIF":1.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147579410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and Numerical Investigation of Ignition of Ammonia–Hydrocarbon Mixtures in Shock Tube Conditions","authors":"A. V. Drakon,&nbsp;A. V. Eremin","doi":"10.1134/S002315842560052X","DOIUrl":"10.1134/S002315842560052X","url":null,"abstract":"<p>The article is devoted to the experimental measurement of ignition delay times of ammonia with additives of CH₄, C₂H₂, C₂H₄, and C₂H₆ behind shock waves and their comparison with the results of numerical simulation using modern kinetic models. A significant discrepancy between the predictions of kinetic mechanisms and the experimental data is demonstrated. The analysis of the sensitivity of the ignition delay time to the rate constants of individual reactions indicates the key role of insufficiently studied reactions of interaction of HO₂ and NH₂ radicals, as well as reactions involving N₂H_<i>x</i> compounds, in the ignition of ammonia at elevated temperatures.</p>","PeriodicalId":682,"journal":{"name":"Kinetics and Catalysis","volume":"66 6","pages":"606 - 617"},"PeriodicalIF":1.4,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147579567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Role of Rh and Mg Oxides in the Etching of Industrial Pt–Pd–Rh–Ru Gauze in the Course of Catalytic Oxidation of Ammonia with Air at 1133 K","authors":"A. N. Salanov,&nbsp;A. N. Serkova,&nbsp;A. S. Zhirnova,&nbsp;L. A. Isupova,&nbsp;V. N. Parmon","doi":"10.1134/S0023158425600865","DOIUrl":"10.1134/S0023158425600865","url":null,"abstract":"<p>Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) at microscope probe electron energies (<i>E</i>₀) of 5 and 20 keV in a range of magnification factors from ×50 to ×100 k were used to characterize the morphology, microstructure and chemical compositions of surface and subsurface regions of etching structures in the industrial Pt−Pd−Rh−Ru gauze with concentrations of 81, 15, 3.5, and 0.5 wt %, respectively, which was used in the oxidation of NH₃ with air at a pressure of 3.6 bar and a temperature of 1133 K. After NH₃ oxidation on the Pt−Pd−Rh−Ru gauze, we observed the microgranular etching structure with grains about 10 µm in size, oxide particles with a diameter of ~80 nm on grain boundaries, and crystal facets 25−50 nm in height on the grain surfaces in the region of weak etching. The oxide particles consisted of 25−50 nm cores with the MgRh₂O₄ spinel composition and 25−50 nm thick SiO₂ shells. These particles were formed during the diffusion of Rh atoms along grain boundaries from the alloy bulk to the surface, the formation of Rh₂O₃ particles, and their reactions with MgO_<i>х</i> and SiO_<i>х</i> impurities from the gas flow of reagents. These processes led to the formation of etch pits, increased the intensity of NH₃ oxidation and temperature, and accelerated the evaporation of volatile oxides PtO₂(gas), RhO₂(gas), etc., into the gas phase, which resulted in the catalyst etching. In the region of strong etching, the etching layer of porous crystal cauliflower agglomerates with different shapes and a size of ~10 µm was observed. The agglomerates had a close phase composition and a low concentration of defects up to a depth of ~500 nm. During the NH₃ oxidation on Pt–Pd–Rh–Ru gauzes, etching structures were formed upon evaporation of volatile oxides PtO₂(gas), RhO₂(gas), etc., on hot regions of the surface and their subsequent condensation on cold fragments of the catalyst.</p>","PeriodicalId":682,"journal":{"name":"Kinetics and Catalysis","volume":"66 5","pages":"563 - 583"},"PeriodicalIF":1.4,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145730170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinetics of the Oxidation of Tetrahydrofuran in Aqueous Solution Initiated by 2,2'-Azobis(2-amidinopropane) Dihydrochloride","authors":"L. R. Yakupova,&nbsp;A. R. Migranov,&nbsp;R. L. Safiullin","doi":"10.1134/S0023158425600233","DOIUrl":"10.1134/S0023158425600233","url":null,"abstract":"<p>The kinetics of tetrahydrofuran oxidation in aqueous solution initiated by 2,2'-azobis(2-amidinopropane) dihydrochloride were studied. The reaction rate was monitored by oxygen uptake using the manometric method. The initiation rate constant of water-soluble 2,2'-azobis(2-amidinopropane) dihydrochloride was determined within the range 303–323 K: log <i>k</i>_i = (11.9 ± 0.6) – (104.8 ± 4.3)/θ [s^–1], θ = 2.303<i>RT</i> kJ/mol. The rate of tetrahydrofuran oxidation (w) was found to depend linearly on its concentration. A quadratic dependence of w on the initiator concentration was observed. The values of <i>k</i>₂(2<i>k</i>₆)^–0.5 (oxidation parameter) for tetrahydrofuran oxidation were obtained. In Arrhenius coordinates, this parameter is expressed as log (<i>k</i>₂(2<i>k</i>₆)^–0.5) = (2.8 ± 0.1) – (36.1 ± 0.7)/θ [L^0.5 mol^–0.5 s^–0.5], θ = 2.303<i>RT</i> kJ/mol. The rate constants for the reactions of tetrahydrofuran peroxyl radicals with α-tocopherol and with 2,2,5,7,8-pentamethyl-6-chromanol in aqueous medium were determined as (2.0 ± 0.3) × 10⁵ L mol^–1 s^–1 (303–318 K) and (2.8 ± 0.5) × 10⁵ L mol^–1 s^–1 (309 K), respectively.</p>","PeriodicalId":682,"journal":{"name":"Kinetics and Catalysis","volume":"66 5","pages":"489 - 495"},"PeriodicalIF":1.4,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145730175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Binuclear Cobalt(II) Complexes Formed by Bridging Arylphosphinic Acids in Tandem Catalytic Process of Ethylene Dimerization and Friedel–Crafts Alkylation of Toluene","authors":"A. A. Kagilev,&nbsp;Z. N. Gafurov,&nbsp;G. E. Bekmukhamedov,&nbsp;I. F. Sakhapov,&nbsp;A. O. Kantyukov,&nbsp;A. B. Dobrynin,&nbsp;V. M. Babaev,&nbsp;O. G. Sinyashin,&nbsp;D. G. Yakhvarov","doi":"10.1134/S0023158425600671","DOIUrl":"10.1134/S0023158425600671","url":null,"abstract":"<p>A novel catalytic system based on 2,2'-bipyridine binuclear cobalt(II) complexes containing bridging phosphinic acid ligands (Ph₂P(O)OH and MesP(H)(O)OH) is presented for tandem oligomerization of ethylene and subsequent Friedel–Crafts alkylation of toluene. It was found that incorporation of sterically less hindered {μ-O₂P(H)Mes}^– ligand significantly enhances the catalytic activity up to 1007 kg <span>({text{mol}}_{{{text{Co}}}}^{{ - 1}},,{{{text{h}}}^{{ - 1}}})</span>, doubling the value compared to the analogous complex with {μ-O₂PPh₂}^– ligand. The reaction products were characterized by GC–MS analysis and include butenes, mono- and dibutyltoluenes along with minor amounts of ethyltoluenes, consistent with the mechanism involving ethylene oligomerization followed by toluene alkylation.</p>","PeriodicalId":682,"journal":{"name":"Kinetics and Catalysis","volume":"66 5","pages":"544 - 551"},"PeriodicalIF":1.4,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145729716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low-Temperature Oxidation and Combustion of Stoichiometric NH3/C2H2/O2/Ar Mixtures at Atmospheric and Elevated Pressures","authors":"K. N. Osipova,&nbsp;V. V. Matyushkov,&nbsp;A. G. Shmakov","doi":"10.1134/S0023158425600841","DOIUrl":"10.1134/S0023158425600841","url":null,"abstract":"<p>Ammonia is a promising fuel, the implementation of which could reduce carbon emissions into the atmosphere. However, to ensure the appropriate combustion characteristics of ammonia, additional technologies are required, since pure ammonia has poor combustion properties. One of them is to use a pilot fuel with high reactivity, for example, acetylene. Successful implementation of NH₃/C₂H₂ mixtures requires a detailed understanding of the chemical processes taking place during their oxidation and combustion. At present, there are very few fundamental works focused on such systems. In this work, the experimental data on the oxidation of a stoichiometric NH₃/C₂H₂/O₂/Ar mixture in a jet-stirred reactor at atmospheric pressure, as well as on the chemical structure of stoichiometric NH₃/C₂H₂/O₂/Ar flames at 1–5 atm, are presented. The work also includes numerical modeling and analysis of NH₃ and C₂H₂ consumption pathways at high and low temperatures, as well as at atmospheric and high pressure. Analysis of the consumption pathways shows that the first steps of oxidation of the fuel mixture components include reactions with the main radicals (H, O, and OH), while the contribution of cross reactions becomes noticeable only at later stages of ammonia and acetylene conversion. The main mechanism of ammonia–acetylene interaction during their oxidation and combustion is the coupling of their individual conversion processes, which involve reactions with H, O, and OH radicals. These radicals are common for both ammonia and acetylene oxidation.</p>","PeriodicalId":682,"journal":{"name":"Kinetics and Catalysis","volume":"66 5","pages":"478 - 488"},"PeriodicalIF":1.4,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145730174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Approaches to the Interpretation of Machine Learning Models Trained with Big Experimental Kinetic Data: An Example of the Suzuki–Miyaura Reaction","authors":"A. F. Schmidt,&nbsp;A. A. Kurokhtina,&nbsp;E. V. Larina,&nbsp;N. A. Lagoda","doi":"10.1134/S0023158425600439","DOIUrl":"10.1134/S0023158425600439","url":null,"abstract":"<p>This paper presents the results of the development and interpretation of machine learning models using big experimental datasets where different ways are implemented to take into account information on the kinetics of reaction using the Suzuki–Miyaura reaction as an example. An original method for interpreting the resulting models was proposed, which consists in the multistep ablation of predictors used in the models, allowing for the identification of the most important reaction parameters required for the successful operation of catalytic systems. The obtained sets of the parameters determining the success of the reaction (rate, selectivity, and yield of the target product; E-factor and other environmental metrics of the reaction, energy efficiency, cost, etc.) as the minimal sets of the predictors of ML models that describe satisfactorily the differential and/or integral quantitative reaction parameters allowed us for the first time to identify the patterns of the functioning mechanism of catalytic systems in the Suzuki–Miyaura reaction, consistent with big experimental kinetic data obtained in a wide range of reaction conditions (nature and amounts of substrates, reagents, catalyst precursors, bases, additives, and solvents; temperature, stirring speed, and type of an atmosphere in the reactor).</p>","PeriodicalId":682,"journal":{"name":"Kinetics and Catalysis","volume":"66 5","pages":"584 - 597"},"PeriodicalIF":1.4,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145730173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Study of the Kinetics of the Mizoroki–Heck Reaction on the Pd/P. yeei Catalyst","authors":"V. N. Soromotin,&nbsp;P. V. Rybochkin,&nbsp;O. A. Kamanina","doi":"10.1134/S0023158425600440","DOIUrl":"10.1134/S0023158425600440","url":null,"abstract":"<p>The kinetics of the Mizoroki–Heck reaction was studied using a green catalyst consisting of Pd nanoparticles (Pd NPs) deposited on the bacterial cells of <i>Paracoccus yeei</i> (<i>P. yeei</i>) VKM B-3302. The study showed that the kinetics of the Mizoroki–Heck reaction catalyzed by Pd/<i>P. yeei</i> and the commercially available Pd/C, at first glance, did not differ significantly. However, more noticeable changes were found in the selectivity and specific productivity of the catalysts. Thus, the bacterial catalyst demonstrated an increase in selectivity for the target product with increasing process temperature. A probable reason for the concomitant increase in selectivity with temperature is the effect of Pd “release” from inside the bacterial cells as a result of their destruction under the action of the solvent and high temperature.</p>","PeriodicalId":682,"journal":{"name":"Kinetics and Catalysis","volume":"66 5","pages":"521 - 527"},"PeriodicalIF":1.4,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145730171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interaction of Hydrogen with Palladium Supported onto an Oxidized Graphite Surface","authors":"M. Yu. Smirnov,&nbsp;A. V. Kalinkin,&nbsp;V. I. Bukhtiyarov","doi":"10.1134/S0023158425600476","DOIUrl":"10.1134/S0023158425600476","url":null,"abstract":"<p>The interaction of palladium deposited by vacuum evaporation onto the surface of highly oriented pyrolytic graphite (HOPG) with hydrogen was studied using X-ray photoelectron spectroscopy (XPS). Graphite was preliminarily subjected to oxidative treatment including the stages of etching by Ar⁺ ions and exposure to air at room temperature. Before contact with hydrogen, the spectrum of the Pd/O-HOPG sample contained two O 1<i>s</i> lines with binding energies <i>E</i>_b ∼ 530.5 and ∼532.5 eV belonging to two types of oxygen atoms in the functional groups on the surface of the carbon support. After interaction with H₂ at a temperature of 150°C and a pressure of 20 mbar, the line with <i>E</i>_b ≈ 530.5 eV disappeared, probably, due to the reduction of the corresponding functional groups. Under these conditions, the surface oxygen was retained in the oxidized graphite sample without deposited palladium (O-HOPG), which indicated the participation of palladium particles in the reduction of oxygen-containing groups. Apparently, dissociation of hydrogen molecules occurred on the palladium surface, followed by spillover of the resulting H atoms onto the carbon support.</p>","PeriodicalId":682,"journal":{"name":"Kinetics and Catalysis","volume":"66 4","pages":"440 - 448"},"PeriodicalIF":1.4,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145479577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}