Progress in Reaction Kinetics and Mechanism最新文献_第3页

Heterogeneous catalysts in the aldol condensation of heptanal with cyclopentanone 庚醛与环戊酮醇缩合反应的多相催化剂

IF 0.7 4区化学

Progress in Reaction Kinetics and Mechanism Pub Date : 2020-05-01 DOI: 10.1177/1468678319825713

Eva Vrbková, T. Kovářová, Eliška Vyskočilová, L. Červený

引用次数: 6

Mechanism of reaction of silica and carbon for producing silicon carbide 二氧化硅与碳反应生成碳化硅的机理

IF 0.7 4区化学

Progress in Reaction Kinetics and Mechanism Pub Date : 2020-05-01 DOI: 10.1177/1468678319891416

B. Abolpour, R. Shamsoddini

引用次数: 14

Kinetic studies of isothermal decomposition of (NH4)4UO2(CO3)3 to uranium oxide (NH4)4UO2(CO3)3等温分解成氧化铀的动力学研究

IF 0.7 4区化学

Progress in Reaction Kinetics and Mechanism Pub Date : 2020-05-01 DOI: 10.1177/1468678319888629

Korichi Smain, Aoudia Nacera, Benelmaddjat Hanane, Kaci Smina, Ousmaal Nafissa

{"title":"Kinetic studies of isothermal decomposition of (NH4)4UO2(CO3)3 to uranium oxide","authors":"Korichi Smain, Aoudia Nacera, Benelmaddjat Hanane, Kaci Smina, Ousmaal Nafissa","doi":"10.1177/1468678319888629","DOIUrl":"https://doi.org/10.1177/1468678319888629","url":null,"abstract":"The ammonium uranyl carbonate, (NH4)4UO2(CO3)3, is an important material used in UO2 and U3O8 ceramics production for the nuclear fuel fabrication. Thermal study and kinetic analysis of ammonium uranyl carbonate conversion under isothermal conditions has been studied in air atmosphere to obtain the tri-uranium octoxide (U3O8), using muffle furnace equipment, UV–visible spectrophotometer, gas adsorption, Hg porosimetry, laser granulometry, and optic spectroscopy. The textural properties (specific surface area, morphology, pore size, grain size, inter-particular porosity, and intra-particular porosity) and characteristics (uranium content and stoichiometry) of the prepared samples were estimated from the physical–chemical characterization. The kinetic parameters were estimated by a fitting of the experimental data. The activation energy Ea , frequency factor A , and reaction rate constants k were calculated from the conventional and iso-conversion kinetic models and were within the range of literature values. The activation energy average values are 36.69 and 30.36 kJ mol−1 by conventional and iso-conversion models, respectively.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87854055","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

Methane–propane hydrate formation and memory effect study with a reaction kinetics model 用反应动力学模型研究甲烷-丙烷水合物的形成和记忆效应

IF 0.7 4区化学

Progress in Reaction Kinetics and Mechanism Pub Date : 2020-05-01 DOI: 10.1177/1468678320901622

Wei Ke, Guangjin Chen, Daoyi Chen

{"title":"Methane–propane hydrate formation and memory effect study with a reaction kinetics model","authors":"Wei Ke, Guangjin Chen, Daoyi Chen","doi":"10.1177/1468678320901622","DOIUrl":"https://doi.org/10.1177/1468678320901622","url":null,"abstract":"Although natural gas hydrates and hydrate exploration have been extensively studied for decades, the reaction kinetics and nucleation mechanism of hydrate formation is not fully understood. In its early stage, gas hydrate formation can be assumed to be an autocatalytic kinetic reaction with nucleation and initial growth. In this work, a reaction kinetics model has been established to form structure II methane–propane hydrate in an isochoric reactor. The computational model consists of six pseudo-elementary reactions for three dynamic processes: (1) gas dissolution into the bulk liquid, (2) a slow buildup of hydrate precursors for nucleation onset, and (3) rapid and autocatalytic hydrate growth after onset. The model was programmed using FORTRAN, with initiating parameters and rate constants that were derived or obtained from data fitted using experimental results. The simulations indicate that the length of nucleation induction is determined largely by an accumulation of oligomeric hydrate precursors up to a threshold value. The slow accumulation of precursors is the rate-limiting step for the overall hydrate formation, and its conversion into hydrate particles is critical for the rapid, autocatalytic reaction. By applying this model, the memory effect for hydrate nucleation was studied by assigning varied initial amounts of precursor or hydrate species in the simulations. The presence of pre-existing precursors or hydrate particles could facilitate the nucleation stage with a reduced induction time, and without affecting hydrate growth. The computational model with the performed simulations provides insight into the reaction kinetics and nucleation mechanism of hydrate formation.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83902972","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: 4

Preparation, characterization and catalytic performance of Pt supported on porous carbonaceous materials in the oxidation of toluene as a volatile organic compound 多孔碳质材料负载Pt在挥发性有机物甲苯氧化中的制备、表征及催化性能

IF 0.7 4区化学

Progress in Reaction Kinetics and Mechanism Pub Date : 2020-05-01 DOI: 10.1177/1468678319887931

Niloofar Atashi, M. H. Peyrovi, N. Parsafard

{"title":"Preparation, characterization and catalytic performance of Pt supported on porous carbonaceous materials in the oxidation of toluene as a volatile organic compound","authors":"Niloofar Atashi, M. H. Peyrovi, N. Parsafard","doi":"10.1177/1468678319887931","DOIUrl":"https://doi.org/10.1177/1468678319887931","url":null,"abstract":"Platinum-carbonaceous catalysts were prepared by the wet impregnation method and tested for catalytic oxidation of toluene as a volatile organic compound. The textural properties of the constructed catalysts were considered by X-ray diffraction, X-ray fluorescence, inductively coupled plasma – optical emission spectroscopy, Fourier transform infrared, scanning electron microscope and N2 adsorption–desorption analysis. The catalytic assessments showed that the best activity (>99%) and high stability and selectivity to CO2 (>99%) are related to platinum-supported carbon nanotube. The curves of the conversion and selectivity demonstrate that the performance of catalysts to eliminate the volatile organic compound and turn it into CO2 conforms to the following descending order: platinum-supported carbon nanotube >platinum-supported graphene >platinum-supported activated carbon >platinum-supported carbon nanofibre. The kinetic of toluene oxidation has been evaluated as a function of toluene and oxygen partial pressures in different temperatures. Two kinetic models (Power Law and Mars–van Krevelen mechanisms) were applied to the reaction and compared with the experimental data. Mars–van Krevelen model is more appropriate than the Power Law model for this reaction as Mars–van Krevelen model showed better prediction of the behaviour of the reaction.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87217307","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: 3

Ni2P/Al2O3 hydrodesulfurization catalysts prepared from hypophosphite under a nitrogen atmosphere 氮气氛下由次亚磷酸盐制备Ni2P/Al2O3加氢脱硫催化剂

IF 0.7 4区化学

Progress in Reaction Kinetics and Mechanism Pub Date : 2020-05-01 DOI: 10.1177/1468678319877643

Yunwu Yu, Lianjie Liang, Yunxue Liu, Chang-Wei Xu, Qing Wang, W. Niu, Changwei Liu

引用次数: 1

Preparation of bimetallic Ni–Fe/MCM-41 catalysts and their catalytic activity for CO methanation Ni-Fe /MCM-41双金属催化剂的制备及其CO甲烷化催化活性

IF 0.7 4区化学

Progress in Reaction Kinetics and Mechanism Pub Date : 2020-05-01 DOI: 10.1177/1468678319870327

Zhang Jiaying

引用次数: 4

Theoretical studies on the kinetics of the hydrogen-abstraction reactions from 1,3,5-trioxane and 1,4-dioxane by OH radicals 羟基自由基对1,3,5-三氧环和1,4-二氧环吸氢反应动力学的理论研究

IF 0.7 4区化学

Progress in Reaction Kinetics and Mechanism Pub Date : 2020-02-01 DOI: 10.1177/1468678319899252

V. Saheb, Aidin Bahadori

{"title":"Theoretical studies on the kinetics of the hydrogen-abstraction reactions from 1,3,5-trioxane and 1,4-dioxane by OH radicals","authors":"V. Saheb, Aidin Bahadori","doi":"10.1177/1468678319899252","DOIUrl":"https://doi.org/10.1177/1468678319899252","url":null,"abstract":"Theoretical investigations have been performed on the kinetics of bimolecular hydrogen-abstraction reactions of 1,3,5-trioxane and 1,4-dioxane cyclic ethers with OH radicals. Hydrogen abstraction from both axial and equatorial positions of 1,3,5-trioxane and 1,4-dioxane was considered. Optimization of the structures, and the calculation of energies, vibrational frequencies and moments of inertia for all the stationary points including reactants, hydrogen-bonded complexes, transition states and products were carried out using density functional theory at the M06-2X level together with the MG3S basis set. Single-point energy calculations on the optimized points were obtained at the CBS-QB3 level. The calculations show that the title reactions proceed through relatively strong hydrogen-bonded complexes due to the hydrogen bonding between the OH radicals and the oxygen atoms of the cyclic ethers. A two-transition state model (an inner tight transition state and an outer loose transition state) was employed to compute the hydrogen-abstraction rate coefficients. The rate coefficients were also computed using conventional transition state theory considering a tight transition state for the purpose of comparison. It was found that when the reactions proceed via inner transition states with relative energies higher than the reactants, the computed rate coefficients are underestimated by conventional transition state theory.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86412876","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: 1

Influence of sulfating method on La–Ni–S2O82–/ZrO2–Al2O3 solid superacid catalyst for n-pentane isomerization 硫酸盐酸化对La-Ni-S2O82 - / ZrO2-Al2O3固体超强酸催化剂正戊烷异构化的影响

IF 0.7 4区化学

Progress in Reaction Kinetics and Mechanism Pub Date : 2020-01-01 DOI: 10.1177/1468678319897724

Haiqiang Zhao, Hua Song, Lele Zhao, Feng Li

{"title":"Influence of sulfating method on La–Ni–S2O82–/ZrO2–Al2O3 solid superacid catalyst for n-pentane isomerization","authors":"Haiqiang Zhao, Hua Song, Lele Zhao, Feng Li","doi":"10.1177/1468678319897724","DOIUrl":"https://doi.org/10.1177/1468678319897724","url":null,"abstract":"La–Ni–S2O82–/ZrO2–Al2O3 catalysts were successfully prepared by two different methods of sulfate impregnation, and the physico-chemical properties of the catalysts were characterized by X-ray diffraction, Brunauer–Emmett–Teller analysis, Fourier transform infrared spectroscopy, pyridine adsorption–infrared spectroscopy, and X-ray photoelectron spectroscopy techniques. Catalytic activities were evaluated in a fixed-bed flow reactor using n-pentane isomerization as the probe reaction. Compared with catalyst La–Ni–S2O82–/ZrO2–Al2O3-I, prepared by the traditional impregnation method, the catalyst La–Ni–S2O82–/ZrO2–Al2O3-W, prepared by the incipient-wetness impregnation method, possessed higher pore volume, pore size, sulfur content, and stronger Brønsted acid sites. The catalytic activity for La–Ni–S2O82–/ZrO2–Al2O3-W was maintained at around 56% within 3000 min with an isopentane selectivity of 88% which showed much greater stability than that of La–Ni–S2O82–/ZrO2–Al2O3-I. This can be attributed to the fact that (1) the large pore size and pore volume of La–Ni–S2O82–/ZrO2–Al2O3-W can largely suppress carbon deposition and (2) the more numerous and stronger Brønsted acid sites for La–Ni–S2O82–/ZrO2–Al2O3-W guaranteed to provide enough acid sites for isomerization during the reaction process.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83128292","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

Magnetically separable Fe3O4-supported Ru–Ni bimetallic catalysts for diformyltricyclodecanes hydrogenation to value-added fine chemicals 磁性可分离fe3o4负载Ru-Ni双金属催化剂用于二甲酰三环癸烷加氢制备高附加值精细化学品

IF 0.7 4区化学

Progress in Reaction Kinetics and Mechanism Pub Date : 2020-01-01 DOI: 10.1177/1468678319825732

Hongyi Li, Yubo Ma

引用次数: 1