Kinetics and Catalysis最新文献_第10页

Regularities of Combustion of Stoichiometric Mixtures of Hydrogen and C2 Hydrocarbons with Air 氢和C2烃的化学计量混合物与空气的燃烧规律

IF 1.4 4区化学

Kinetics and Catalysis Pub Date : 2025-06-03 DOI: 10.1134/S0023158425600130

V. M. Shvartsberg, A. G. Shmakov

{"title":"Regularities of Combustion of Stoichiometric Mixtures of Hydrogen and C2 Hydrocarbons with Air","authors":"V. M. Shvartsberg, A. G. Shmakov","doi":"10.1134/S0023158425600130","DOIUrl":"10.1134/S0023158425600130","url":null,"abstract":"This work is dedicated to a numerical study of the chemistry and mechanism of combustion for binary fuels consisting of hydrogen and C2 hydrocarbons. These fuels are considered very promising because they allow effective control over combustion characteristics by adjusting the ratio of the fuel components. It was found that replacing part of the hydrogen with acetylene in a stoichiometric premixed H2/air flame at a constant equivalence ratio results in a noticeable increase in the flame temperature, with a slight decrease in the flame speed. In the case of ethylene, the decrease in flame velocity is more significant. The flame temperature initially drops by 3 K and then slightly increases as the ethylene concentration rises. When part of the hydrogen is replaced by ethane, both the temperature and flame velocity decrease. According to the modeling results, partial replacement of hydrogen with acetylene, ethylene, or ethane in flames reduces the concentration of chain carriers (H, O, and OH), with the most significant effect on the concentration of the H atom. This indicates the determining influence of H on the speed of these flames, which is confirmed by the correlation between the normalized H concentrations and flame velocities. It was found that the higher concentration of H in the H2/C2H2/air flame is due to the significant contribution of the C2H2 + O ( rightleftarrows ) HCCO + H step to H atom formation. The rate of this step in flames with added ethylene and ethane is significantly lower due to the much lower concentration of C2H2. On the one hand, the consumption of chain carriers during interactions with carbon-containing compounds negatively affects the H2/C2H2/air flame speed, while on the other hand, the increase in flame temperature has a positive effect due to the high endothermicity of acetylene.","PeriodicalId":682,"journal":{"name":"Kinetics and Catalysis","volume":"66 1","pages":"15 - 27"},"PeriodicalIF":1.4,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145141831","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}

引用次数: 0

Selective Dehydration of Glycerol to Hydroxyacetone over Cu-, Ag-, and AgFe-Mordenites 在Cu-， Ag-和agfe -丝光沸石上甘油选择性脱水制羟基丙酮

IF 1.4 4区化学

Kinetics and Catalysis Pub Date : 2025-04-29 DOI: 10.1134/S0023158425600038

M. G. Shelyapina, I. A. Zvereva, T. A. Kryuchkova, T. F. Sheshko, P. V. Akhmina, L. V. Yafarova, J. Antunez-Garcia, V. Petranovskii

{"title":"Selective Dehydration of Glycerol to Hydroxyacetone over Cu-, Ag-, and AgFe-Mordenites","authors":"M. G. Shelyapina, I. A. Zvereva, T. A. Kryuchkova, T. F. Sheshko, P. V. Akhmina, L. V. Yafarova, J. Antunez-Garcia, V. Petranovskii","doi":"10.1134/S0023158425600038","DOIUrl":"10.1134/S0023158425600038","url":null,"abstract":"The increasing demands of the hydroxyacetone (also known as acetol) market require more efficient acetol production technologies. The development of new effective catalysts for glycerol dehydration to acetol at mild condition is an important task. In this study, dehydration of glycerol to acetol on microporous sodium mordenite (MOR) modified by conventional ion exchange with Cu2+, Ag+ and Ag+Fe2+ was investigated within a temperature range from 100 to 250°C. The transition metal content after ion exchange procedure was determined by EDX: 4.6 wt % of Cu for CuMOR, 2.8 wt % of Ag for AgMOR, 2.3 and 0.2 wt % of Ag and Fe, respectively, for AgFeMOR. H2-TPR indicates the presence of different types of active sites (Cu2+, Ag+, ({text{Ag}}_{m}^{{n + }}), Fe+2). The glycerol conversion and the acetol yield over the zeolite samples increase in the CuMOR < AgFeMOR < AgMOR series. For AgMOR, glycerol conversion achieves ~90% at 175°C (with an acetol yield of about 76%), the presence of Fe2+ reduces the catalytic performance of the catalyst. The copper-exchanged catalyst exhibits the poorest catalytic performance. The proposed reaction mechanism of glycerol dehydration over mordenite involves a preparative step (glycerol as reducing media, forms a catalyst by interacting with cations introduced into the zeolite), and then on these formed neutral metallic sites the conversion of glycerol to the final product occurs; the selectivity of the reaction is mainly determined by steric constraints.","PeriodicalId":682,"journal":{"name":"Kinetics and Catalysis","volume":"66 1","pages":"43 - 53"},"PeriodicalIF":1.4,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145144869","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}

引用次数: 0

FTIR Study of CO Adsorbed on Ag-Mordenite 银丝光石吸附CO的FTIR研究

IF 1.4 4区化学

Kinetics and Catalysis Pub Date : 2025-04-29 DOI: 10.1134/S0023158425600142

A. Tsyganenko, Y. Shergin, M. Shelyapina, E. Satikova, V. Petranovskii

{"title":"FTIR Study of CO Adsorbed on Ag-Mordenite","authors":"A. Tsyganenko, Y. Shergin, M. Shelyapina, E. Satikova, V. Petranovskii","doi":"10.1134/S0023158425600142","DOIUrl":"10.1134/S0023158425600142","url":null,"abstract":"Ag-mordenite with atomic Si/Al ratio 6.5 was characterized by FTIR spectra of adsorbed CO. Besides H-bonding with surface OH groups and side-on interaction with oxygen atoms of siloxane bridges, adsorption on Ag+ ions occurs, which accounts for the band at 2193–2178 cm–1. The exact position of this band depends on the coverage, it shifts to higher wavenumbers upon desorption, until disappearance after heating in vacuum at 300°C. Frequency growth is accompanied by increase in the integrated absorption coefficient up to 8.0 cm/μmol, which is much higher than that of a free CO molecule. We assume that the changes in band position and absorbance are due to the transition from di- to monocarbonyl, whose bands are not resolved in the fundamental vibration region, but the splitting of overtone band confirms such supposition. The position of the high-frequency component of overtone band is even higher than the double frequency of the fundamental vibration, indicating that the anharmonicity of adsorbed CO is vanished or becomes negative. High intensity of overtone bands infers on nonlinear dependence of molecular dipole on the vibrational coordinate. Spectra registered at elevated temperature do not show bands that could be assigned to O-bonded CO species. Quantum chemical calculation confirms the absence of linkage isomerism for CO bound to Ag+ cations.","PeriodicalId":682,"journal":{"name":"Kinetics and Catalysis","volume":"66 1","pages":"119 - 127"},"PeriodicalIF":1.4,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145145338","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}

引用次数: 0

Structural, Electronic and Zinc Doping Effect on the Catalytic and Optical Properties of Lanthanum Orthochromite Perovskite: Experimental and Theoretical Study 结构、电子和锌掺杂对镧钙钛矿催化和光学性能的影响：实验和理论研究

IF 1.4 4区化学

Kinetics and Catalysis Pub Date : 2025-04-29 DOI: 10.1134/S0023158424602018

Abdelhakim Chadli, Ilham Chadli, Ayman Hammoudeh, Abderrahmane Cheriet, Gabriele Manca

{"title":"Structural, Electronic and Zinc Doping Effect on the Catalytic and Optical Properties of Lanthanum Orthochromite Perovskite: Experimental and Theoretical Study","authors":"Abdelhakim Chadli, Ilham Chadli, Ayman Hammoudeh, Abderrahmane Cheriet, Gabriele Manca","doi":"10.1134/S0023158424602018","DOIUrl":"10.1134/S0023158424602018","url":null,"abstract":"In this work, lanthanum orthochromite (LaCrO3; LCO) and lanthanum orthochromite doped with zinc in the B site ((LaCr1–xZnxO3: x = 0.1, 0.2, 0.3; LCZO) were synthesized by the sol–gel citrate route and investigated with respect to their crystal structure, surface morphology and optical band gap energy by means of X-ray diffraction, scanning electron microscopy and UV–Vis spectrophotometry. Moreover, the band structure, density of states (DOS) and electronic density were calculated for LCO using the DFT–FP–LAPW method. The XRD analysis showed that LCO sintered at 1000°C and LCZO sintered at 1100°C crystallize in a perovskite-type orthorhombic structure. The computed band gap energy was about 2.93 eV for pure LCO oxide. On the other hand, the experimental results showed a remarkable decrease in the LCO optical band gap from 3.0 to 2.7 eV with increased Zn content. The prepared systems were also tested with respect to their catalytic activity in the oxidative dehydrogenation of 1-butene, where doping with Zn was found to improve the catalytic performance of LCZO catalysts, leading to a maximum selectivity to 1,3-butadiene of 35% at a zinc doping level of x = 0.2.","PeriodicalId":682,"journal":{"name":"Kinetics and Catalysis","volume":"66 1","pages":"54 - 64"},"PeriodicalIF":1.4,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145145336","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}

引用次数: 0

Aspects of Photoelectrocatalytic Reduction of CO2 on Titanium Oxide Catalysts Modified with Ag, Au, and Pt Ag、Au、Pt改性氧化钛催化剂上光电催化还原CO2的研究

IF 1.3 4区化学

Kinetics and Catalysis Pub Date : 2025-02-25 DOI: 10.1134/S0023158424602365

D. A. Polskikh, D. S. Selishchev, M. N. Lyulyukin, D. V. Kozlov

{"title":"Aspects of Photoelectrocatalytic Reduction of CO2 on Titanium Oxide Catalysts Modified with Ag, Au, and Pt","authors":"D. A. Polskikh, D. S. Selishchev, M. N. Lyulyukin, D. V. Kozlov","doi":"10.1134/S0023158424602365","DOIUrl":"10.1134/S0023158424602365","url":null,"abstract":"The work investigated the influence of the nature and amount of the applied noble metal, as well as the physicochemical properties of the initial TiO2 on the process of photoelectrocatalytic reduction of CO2. Catalysts of the compositions x% Me/TiO2 (where Me = Ag, Au, Pt; and x = 0.1–2 wt %) were synthesized on the basis of titanium dioxide of the brands Evonik P25 (anatase : rutile ratio = 75 : 25) and EuroSupport (anatase >99%) by chemical reduction from metal salts using NaBH4. The samples were characterized by X‑ray powder diffraction analysis, X-ray photoelectron spectroscopy, and UV–Vis diffuse reflectance spectroscopy. The catalytic properties of the obtained samples were studied in the photoelectrocatalytic reduction of carbon dioxide in 0.1 M KHCO3 electrolyte at a potential of –700 mV versus Ag/AgCl/KCl(sat) under irradiation at a wavelength of 371 nm. Data on the accumulation of total organic carbon in the solution showed that, for each supported metal, the activity of the samples based on EuroSupport anatase-rich TiO2 is 20% higher than the activity of the samples based on Evonik P25 rutile-containing TiO2 at identical values of current efficiency. A conclusion was made about the observed decrease in electron energy and the reducing capacity of the catalyst by the rutile phase in Evonik P25 TiO2. Based on the relationship between the activity and utilization efficiency of metals in the CO2 reduction process, Au was selected as the preferred metal for photoelectrocatalytic CO2 reduction.","PeriodicalId":682,"journal":{"name":"Kinetics and Catalysis","volume":"65 6","pages":"663 - 671"},"PeriodicalIF":1.3,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143481021","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}

引用次数: 0

Hydrogen Production from Aqueous Glucose Solutions over g-C3N4/Pt/TiO2 Photocatalysts g-C3N4/Pt/TiO2光催化剂催化葡萄糖水溶液制氢研究

IF 1.3 4区化学

Kinetics and Catalysis Pub Date : 2025-02-25 DOI: 10.1134/S0023158424602353

A. Yu. Kurenkova, S. N. Kharina, E. E. Aydakov, E. A. Kozlova

{"title":"Hydrogen Production from Aqueous Glucose Solutions over g-C3N4/Pt/TiO2 Photocatalysts","authors":"A. Yu. Kurenkova, S. N. Kharina, E. E. Aydakov, E. A. Kozlova","doi":"10.1134/S0023158424602353","DOIUrl":"10.1134/S0023158424602353","url":null,"abstract":"In this work, a series of composite photocatalysts based on graphitic carbon nitride and platinized titanium dioxide was synthesized and the reaction kinetics of photocatalytic hydrogen evolution from aqueous solutions of glucose under the visible light irradiation (440 nm) was studied. The graphitic carbon nitride was prepared by the thermal polycondensation of melamine at 600°C with the subsequent thermal exfoliation. The g-C3N4/Pt/TiO2 composite photocatalysts were produced by the self-assembly of g-C3N4 and Pt/TiO2. Varying the g-C3N4 content showed that the sample containing 10 wt % g-C3N4 had the highest activity. The dependence of the rate of hydrogen evolution on the initial glucose concentration obeyed the Langmuir–Hinshelwood equation; the adsorption constant was Kads = 76 ± 14 M–1, and the apparent rate constant was kr = 0.69 ± 0.02 μmol/min. The photocatalyst 10% g-C3N4/1% Pt/TiO2 was studied using X-ray photoelectron spectroscopy both before and after the reaction of hydrogen evolution. It was found that a portion of platinum in the initial photocatalyst was present in the oxidized state (+2), and platinum was completely reduced to a metallic state during the photocatalytic reaction. The activity of the photocatalyst 10% g-C3N4/1% Pt/TiO2 under the solar simulator light irradiation (AM1.5G) was 560 μmol h–1 g–1.","PeriodicalId":682,"journal":{"name":"Kinetics and Catalysis","volume":"65 6","pages":"703 - 709"},"PeriodicalIF":1.3,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143481046","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}

引用次数: 0

Butynes Hydrogenation with Parahydrogen over Immobilized Iridium Catalyst 固定化铱催化剂上对氢丁烯加氢反应

IF 1.3 4区化学

Kinetics and Catalysis Pub Date : 2025-02-25 DOI: 10.1134/S0023158424602705

D. B. Burueva, I. V. Skovpin, L. M. Kovtunova, E. S. Kononenko, V. I. Bukhtiyarov, I. V. Koptyug

引用次数: 0

Application of a Convolutional Neural Network for Automated Analysis of X-ray Photoelectron Spectra of Heterogeneous Catalysts 卷积神经网络在非均相催化剂x射线光电子能谱自动分析中的应用

IF 1.3 4区化学

Kinetics and Catalysis Pub Date : 2025-02-25 DOI: 10.1134/S0023158424602687

A. A. Vakhrushev, A. V. Matveev, A. V. Nartova

引用次数: 0

Comparison of the Reactivity of O2 and NO2 Relative to Palladium Supported on HOPG HOPG载体上O2和NO2相对于钯的反应性比较

IF 1.3 4区化学

Kinetics and Catalysis Pub Date : 2025-02-25 DOI: 10.1134/S0023158424601992

M. Yu. Smirnov, A. V. Kalinkin, A. N. Salanov, V. I. Bukhtiyarov

{"title":"Comparison of the Reactivity of O2 and NO2 Relative to Palladium Supported on HOPG","authors":"M. Yu. Smirnov, A. V. Kalinkin, A. N. Salanov, V. I. Bukhtiyarov","doi":"10.1134/S0023158424601992","DOIUrl":"10.1134/S0023158424601992","url":null,"abstract":"A comparative study of the interaction of palladium supported on the surface of highly oriented pyrolytic graphite (Pd/HOPG) with oxygen and nitrogen dioxide was carried out using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The samples were prepared by vacuum deposition of metallic Pd onto HOPG; the size of the resulting particles was ≤5 nm. The samples were treated in oxygen at room temperature or 150°C and a pressure of 20 mbar. The interaction with NO2 was carried out at room temperature and a pressure of 10–6 mbar. For the two oxidants used, O2 and NO2, fundamental differences in their effects on Pd/HOPG were found. At room temperature, the treatment in O2 was limited by the formation of some amount of oxygen-containing compounds CxOy on the surface of the carbon support. After increasing the temperature to 150°C, a portion of palladium was converted into a PdO oxide. When NO2 was used as an oxidizing reagent, intense oxidative destruction of graphite occurred to a depth of 10–15 graphene layers. Palladium remained in a metallic state, but its particles penetrated deep into the carbon support, which led to significant screening of its lines in the X-ray photoelectron spectrum and the disappearance of particles in SEM images. A possible mechanism for the interaction of Pd/HOPG with O2 and NO2 has been proposed, which allowed us to explain the different behaviors of these oxidizing molecules.","PeriodicalId":682,"journal":{"name":"Kinetics and Catalysis","volume":"65 6","pages":"763 - 774"},"PeriodicalIF":1.3,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480945","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}

引用次数: 0

Influence of the Nature of Medium Modifiers on the Properties of Palladium–Phosphorus Catalysts in Direct Synthesis of Hydrogen Peroxide 介质改性剂性质对直接合成过氧化氢钯磷催化剂性能的影响

IF 1.3 4区化学

Kinetics and Catalysis Pub Date : 2025-02-25 DOI: 10.1134/S0023158424601554

L. B. Belykh, E. A. Milenkaya, N. I. Skripov, T. A. Kornaukhova, F. K. Schmidt

引用次数: 0