International Journal of Chemical Kinetics最新文献

{"title":"A theoretical study on the mechanism and kinetics of the reactions between diazine isomers and OH radicals","authors":"Seyyed Rasoul Hashemi,&nbsp;Jeffrey Koopman,&nbsp;Gunnar Nyman","doi":"10.1002/kin.21711","DOIUrl":"10.1002/kin.21711","url":null,"abstract":"<p>The reactions of pyrazine, pyridazine, and pyrimidine with hydroxyl radicals are theoretically studied. The barrier heights obtained with different electronic structure methods indicate that the reactions can competitively proceed via either abstraction of a hydrogen atom by an OH radical or OH addition to carbon sites. However, the rate constants computed within the temperature range 200 to 1500 K suggest that tunneling play a role resulting in large branching ratios in favor of hydrogen abstraction channels at lower temperatures.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"56 6","pages":"347-355"},"PeriodicalIF":1.5,"publicationDate":"2024-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/kin.21711","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139987606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Degradation of indigo carmine dye with peroxydisulphate ion in aqueous sulphuric acid phase: Kinetic study","authors":"Patricia Ese Umoru,&nbsp;Ikechukwu Ugbaga Nkole,&nbsp;Titus Tobechukwu Ezeh","doi":"10.1002/kin.21710","DOIUrl":"10.1002/kin.21710","url":null,"abstract":"<p>The quest for cleaner environments is a global concern. Hence, the investigation of degradation of the indigo carmine dye (IC) with peroxydisulphate ion in an aqueous sulphuric acid system with a view to understanding its kinetic degradation and mechanism. The degradation depicts first-order kinetics in [S₂O₈²⁻] and [IC], and the degradation mole ratio of IC: S₂O₈²⁻ is 1:1. The degradation rate is dependent on the change in ionic strength and medium permittivity of the system. Also, added ions (NH₄⁺ and NO₃⁻) influence the degradation rate of the dye which further supported the outcome of the change in ionic strength. Free radical participation is ruled out. The experimental rate law is given as (Kk₃[H⁺])[IC][S₂O₈²⁻]. Owing to the absence of detectable intermediates in the degradation process, an outer-sphere mechanism is proposed. The study is significant in textile industries and medical settings for making environments less toxic with a well-understood degradation rate pathway.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"56 6","pages":"339-346"},"PeriodicalIF":1.5,"publicationDate":"2024-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139948535","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":"Ab initio kinetic study on the abstraction reactions of methylcyclohexane and implications for high-temperature ignition simulations from shock tube experiment","authors":"Jinhu Liang,&nbsp;Ming-Xu Jia,&nbsp;Qian Yao,&nbsp;Guo-Jun Kang,&nbsp;Yang Zhang,&nbsp;Fengqi Zhao,&nbsp;Quan-De Wang","doi":"10.1002/kin.21709","DOIUrl":"10.1002/kin.21709","url":null,"abstract":"<p>Methylcyclohexane (MCH) is the simplest alkylated cyclohexane, and has been widely employed in surrogate models to represent the cycloalkanes in real fuels. Thus, extensive experimental and kinetic modeling studies have been performed to understanding the combustion chemistry of MCH. However, through a detailed literature analysis, there still lack a systematic theoretical study on the abstraction reactions of MCH, which are the main initial oxidation pathway of MCH. Herein, this work reports a systematic ab initio chemical kinetic study on the abstraction reactions of MCH with different radicals/species. Specifically, reaction rate constants of 30 abstraction reactions of MCH with H/O/OH/O₂/HO₂/CH₃ at different sites are computed using transition state theory (TST) by using quantum chemistry calculation results at DLPNO-CCSD(T)/CBS//M06-2X/cc-pVTZ level. The computed results are incorporated into a detailed mechanism to simulate newly measured ignition delay times (IDTs) of MCH in this work at equivalence ratios of 0.5, 1.0, and 2.0, pressures of 2 and 5 bar, temperatures ranging from 1140 to 1640 K. The updated detailed mechanism demonstrates improvement in the prediction of IDTs, especially at fuel-rich conditions. The fuel concentration and dilution effect on the IDTs are discussed, and a general Arrhenius expression is adopted to fit the IDTs from both this work and literature work. This work should be valuable for further optimization of detailed kinetic mechanisms and also for gaining insight into the combustion chemistry of MCH.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"56 6","pages":"325-338"},"PeriodicalIF":1.5,"publicationDate":"2024-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139582468","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":"Thermodynamic properties calculations of Cu-based species","authors":"Muhammad Yousuf,&nbsp;Muhammad Fahad Arshad,&nbsp;Zhen-Yu Tian","doi":"10.1002/kin.21708","DOIUrl":"10.1002/kin.21708","url":null,"abstract":"<p>This work focuses on the thermodynamic property calculations of seven copper-based species, namely copper, copper oxide, copper hydroxide, copper nitrate, and copper hydroxide nitrate. The structures of these species were optimized to achieve stable geometries. The density functional theory (DFT) calculations were employed to obtain various thermodynamic properties such as entropy, enthalpy, Gibbs free energy, and heat capacity at constant pressure. A comparative investigation was performed on the temperature-dependent behavior of key thermodynamic parameters. Species characterized by a higher quantity of atoms tend to demonstrate elevated thermodynamic properties. Copper and copper hydroxide nitrate had higher thermodynamic values than their oxides and other counterparts. It should be noted that the thermodynamic properties of copper hydroxide nitrate were newly computed, and the results showed that the thermodynamic values of the compound structure were higher than their crystalline counterparts. Moreover, due to the large structure size and solid phase, these thermodynamic values exhibited discrepancies with previously calculated computational and experimental values. The thermodynamic property values that depended on temperature were transformed into NASA 7-Coefficient polynomials parameterization. The newly determined thermodynamic data and polynomials provide valuable insights into the thermodynamic behavior of copper-based species. It will help better understand their surface sites and different crystalline structures. Such data can be used to better understand a variety of industrial processes, including combustion, gasification, chemical synthesis, and further to enhance efficiency, reduce costs, and minimize hazardous environmental emissions.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"56 5","pages":"310-322"},"PeriodicalIF":1.5,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139561243","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":"Synthesis of isobutyl cinnamate based on DESs catalyst: Optimization and kinetics","authors":"Jumei Xu,&nbsp;Ningrui Zhao,&nbsp;Zuoxiang Zeng,&nbsp;Weilan Xue","doi":"10.1002/kin.21707","DOIUrl":"10.1002/kin.21707","url":null,"abstract":"<p>In this work, the optimum process conditions and kinetics of the green synthesis of isobutyl cinnamate using deep eutectic solvents (DESs) as catalysts were investigated. Isobutyl cinnamate is a spice with low toxicity and is widely used in the food industry. However, there is a lack of reports on its green synthesis. Three DESs were prepared by adjusting the mixing ratio of choline chloride (ChCl) and p-toluenesulfonic acid (PTSA). Response surface methodology with Box-Behnken design (RSM-BBD) was used to optimize the process parameters of the esterification of cinnamic acid with isobutanol. The effects of catalyst loading, stirring speed, cinnamic acid/isobutanol molar ratio, and temperature on the conversion of cinnamic acid over time were evaluated. Using ChCl-PTSA as a catalyst, the kinetics data and chemical equilibrium constants of the esterification were determined at a temperature range of 353.15–383.15 K. The pseudo-homogeneous (PH) model based on activity was then adopted to describe the kinetics of the reaction, and the relative deviations between the experimental values and the calculated ones by PH model are less than 5.5%. Thermodynamic data (Δ<i>_rH</i>⁰, Δ<i>_rS</i>⁰, Δ<i>_rG</i>⁰) for the esterification reaction was calculated as well. In addition, the results of six consecutive cycles of the catalyst showed that ChCl-PTSA has good stability and recyclability.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"56 5","pages":"296-309"},"PeriodicalIF":1.5,"publicationDate":"2024-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139483487","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":"Theoretical study on iso-pentanol oxidation chemistry: Fuel radical isomerization and decomposition kinetics and mechanism development","authors":"Chao Zhou,&nbsp;Yaozong Duan,&nbsp;Zhen Huang,&nbsp;Dong Han","doi":"10.1002/kin.21706","DOIUrl":"10.1002/kin.21706","url":null,"abstract":"<p>This study undertakes a detailed theoretical investigation into the iso-pentanol radical isomerization and decomposition kinetics and the mechanism development of the iso-pentanol oxidation. The CCSD(T)/CBS//M08-HX/6-311+G(2df,2p) method was adopted to calculate the reaction potential energy surface. The reaction rate coefficients were calculated by variational transition state theory (VTST) with multistructural torsional (MS-T) partition function and small curvature tunneling (SCT) correction. Moreover, the pressure-dependent rate coefficients were determined using the system-specific quantum Rice-Ramsperger-Kassel theory (SS-QRRK). The variational and tunneling effects were discussed, and the dominant reaction channels were identified. It reveals that the isomerization reactions play a significant role at low temperatures, while the decomposition reactions dominate the high-temperature regime. Notably, the quantitative rate expressions for iso-pentanol radical decomposition reactions were also obtained. Furthermore, a new kinetic model incorporating the calculated rate coefficients was constructed, exhibiting satisfactory prediction performance on ignition delay times and improved predictive accuracy of species mole fractions. This work provides accurate rate data of isomerization and decomposition kinetics and contributes to a more comprehensive understanding of the iso-pentanol oxidation mechanism.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"56 5","pages":"279-295"},"PeriodicalIF":1.5,"publicationDate":"2024-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139412497","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":"Aqueous-phase reforming of model compounds of wet biomass to hydrogen on alumina-supported metal catalysts","authors":"Rohini S. Zambare,&nbsp;Prakash D. Vaidya","doi":"10.1002/kin.21704","DOIUrl":"10.1002/kin.21704","url":null,"abstract":"<p>Catalytic aqueous-phase reforming (APR) of wet biomass such as microalgae and activated sludge is a potential technique for the production of H₂-rich gaseous products. In the present work, model compounds such as ethylene glycol, xylose and alanine were selected as representatives of the polyols, carbohydrates and proteins in wet biomass. APR trials were performed in a stirred batch reactor using commercial Pt/Al₂O₃ and Ru/Al₂O₃ catalysts. The reforming reactions were investigated at different conditions: temperature (T), 498 to 518 K, feed concentration, 1 to 5 wt. %, catalyst loading (ω), 2 to 6 kg/m³, and reaction time (t), 1 to 6 h. The commercial Pt/Al₂O₃ catalyst exhibited higher reforming activity. The influence of reaction parameters on turnover frequency (TOF_H₂), hydrogen yield (Y-H₂) and carbon-to-gas conversion (C to G conversion) was studied. The values of TOF_H₂ for Pt/Al₂O₃ were measured at T = 518 K, ω = 2 kg/m³ and t = 3 h using 1 wt% feed and these values were 19.2, 4 and 6 1/min for ethylene glycol, xylose and alanine. The values of TOF_H₂ over Ru/Al₂O₃ under identical conditions were: ethylene glycol–12.4, xylose–1.4 and alanine–5.4 1/min. The activation energies for H₂ production from ethylene glycol, xylose and alanine over Pt/Al₂O₃ and Ru/Al₂O₃ catalysts were determined. APR of the mixture of model compounds was also studied over laboratory-made Pt/Al₂O₃ and Ru/Al₂O₃ catalysts at the optimum reaction conditions. Thus, this work has provided crucial insights into the production of H₂ from model compounds of wet biomass using Al₂O₃-supported catalysts.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"56 5","pages":"265-278"},"PeriodicalIF":1.5,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138957937","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":"Automatic mechanism generation for the combustion of advanced biofuels: A case study for diethyl ether","authors":"Christian A. Michelbach,&nbsp;Alison S. Tomlin","doi":"10.1002/kin.21705","DOIUrl":"10.1002/kin.21705","url":null,"abstract":"<p>Advanced biofuels have the potential to supplant significant fractions of conventional liquid fossil fuels. However, the range of potential compounds could be wide depending on selected feedstocks and production processes. Not enough is known about the engine relevant behavior of many of these fuels, particularly when used within complex blends. Simulation tools may help to explore the combustion behavior of such blends but rely on robust chemical mechanisms providing accurate predictions of performance targets over large regions of thermochemical space. Tools such as automatic mechanism generation (AMG) may facilitate the generation of suitable mechanisms. Such tools have been commonly applied for the generation of mechanisms describing the oxidation of non-oxygenated, non-aromatic hydrocarbons, but the emergence of biofuels adds new challenges due to the presence of functional groups containing oxygen. This study investigates the capabilities of the AMG tool Reaction Mechanism Generator for such a task, using diethyl ether (DEE) as a case study. A methodology for the generation of advanced biofuel mechanisms is proposed and the resultant mechanism is evaluated against literature sourced experimental measurements for ignition delay times, jet-stirred reactor species concentrations, and flame speeds, over conditions covering <i>φ</i> = 0.5–2.0, <i>P</i> = 1–100 bar, and <i>T</i> = 298–1850 K. The results suggest that AMG tools are capable of rapidly producing accurate models for advanced biofuel components, although considerable upfront input was required. High-quality fuel specific reaction rates and thermochemistry for oxygenated species were required, as well as a seed mechanism, a thermochemistry library, and an expansion of the reaction family database to include training data for oxygenated compounds. The final DEE mechanism contains 146 species and 4392 reactions and in general, provides more accurate or comparable predictions when compared to literature sourced mechanisms across the investigated target data. The generation of combustion mechanisms for other potential advanced biofuel components could easily capitalize on these database updates reducing the need for future user interventions.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"56 4","pages":"233-262"},"PeriodicalIF":1.5,"publicationDate":"2023-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/kin.21705","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138965915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oxidation of the 1-naphthyl radical C10H7• with oxygen: Thermochemistry, kinetics, and possible reaction pathways","authors":"Nadia Sebbar,&nbsp;Henning Bockhorn,&nbsp;Dimosthenis Trimis","doi":"10.1002/kin.21702","DOIUrl":"10.1002/kin.21702","url":null,"abstract":"<p>The reaction of the 1-naphthyl radical C₁₀H₇• (A2•) with molecular (³O₂) and atomic oxygen, as part of the oxidation reactions of naphthalene, is examined using ab-initio and DFT quantum chemistry calculations. The study focuses on pathways that produce the intermediate final products CO, phenyl and C₂H₂, which may constitute a repetitive reaction sequence for the successive diminution of six-membered rings also in larger polycyclic aromatic hydrocarbons. The primary attack of ³O₂ on the 1-naphthyl radical leads to a peroxy radical C₁₀H₇OO• (A2OO•), which undergoes further propagation and/or chain branching reactions. The thermochemistry of intermediates and transition state structures is investigated as well as the identification of all plausible reaction pathways for the A2• + O₂ / A2• + O systems. Structures and enthalpies of formation for the involved species are reported along with transition state barriers and reaction pathways. Standard enthalpies of formation are calculated using ab initio (CBS-QB3) and DFT calculations (B3LYP, M06, APFD). The reaction of A2• with ³O₂ opens six main consecutive reaction channels with new ones not currently considered in oxidation mechanisms. The reaction paths comprise important exothermic chain branching reactions and the formation of unsaturated oxygenated hydrocarbon intermediates. The primary attack of ³O₂ at the A2• radical has a well depth of some 50 kcal mol⁻¹ while the six consecutive channels exhibit energy barriers below the energy of the A2• radical. The kinetic parameters of each path are determined using chemical activation analysis based on the canonical transition state theory calculations. The investigated reactions could serve as part of a comprehensive mechanism for the oxidation of naphthalene. The principal result from this study is that the consecutive reactions of the A2• radical, viz. the channels conducting to a phenyl radical C₆H₅•, CO₂, CO (which oxidized to CO₂) and C₂H₂ are by orders of magnitude faster than the activation of naphthalene by oxygen (A2 + O₂ → A2• + HO₂).</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"56 4","pages":"210-232"},"PeriodicalIF":1.5,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/kin.21702","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138574597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative study of the high-temperature auto-ignition of cyclopentane and tetrahydrofuran","authors":"Hong-Quan Do,&nbsp;Benoîte Lefort,&nbsp;Zeynep Serinyel,&nbsp;Luis LeMoyne,&nbsp;Guillaume Dayma","doi":"10.1002/kin.21703","DOIUrl":"10.1002/kin.21703","url":null,"abstract":"<p>Cyclopentane (C₅H₁₀) and tetrahydrofuran (C₄H₈O) are both five-membered ring compounds. The present study compares the auto-ignition of cyclopentane and tetrahydrofuran in a high-pressure shock-tube (20 atm). Twelve different mixtures were investigated at two different fuel initial mole fractions (1% and 2%): at X_fuel = 1%, three equivalence ratios, kept constant between cyclopentane and tetrahydrofuran, were studied (0.5, 1, and 2), whereas three X_fuel/X_O2 were investigated when X_fuel = 2%. A detailed kinetic mechanism was developed to reproduce cyclopentane and tetrahydrofuran auto-ignition. The agreement between our experimental results and the modeling is very good. This mechanism was used to explain the similarities and differences observed between cyclopentane and tetrahydrofuran auto-ignition.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"56 4","pages":"199-209"},"PeriodicalIF":1.5,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138568463","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}