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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 Q3 CHEMISTRY, PHYSICAL Pub Date : 2020-05-01 DOI: 10.1177/1468678319825713
Eva Vrbková, T. Kovářová, Eliška Vyskočilová, L. Červený
A large number of heterogeneous catalysts were tested in the aldol condensation of heptanal with cyclopentanone. There are many possible products from this aldol condensation, among which the most desired is 2-heptylidenecyclopentanone. As heterogeneous catalysts, the following were tested: caesium modified zeolites, functionalized MCM-41, and single (MgO, CaO, ZnO) and double (Mo–Si, Mg–Al, Zn–Al) metal oxides. The activity of modified zeolites and functionalized zeolites in this aldol condensation was low, whereas single and double metal oxides possessed high activity. The highest selectivity to the desired 2-heptylidenecyclopentanone (52%) was obtained using magnesium oxide as catalyst.
在庚醛与环戊酮醛缩合反应中,测试了大量的非均相催化剂。这种醛缩反应有许多可能的产物,其中最理想的是2-庚基环戊酮。作为非均相催化剂,测试了以下催化剂:铯改性沸石,功能化MCM-41,单(MgO, CaO, ZnO)和双(Mo-Si, Mg-Al, Zn-Al)金属氧化物。改性沸石和功能化沸石在醛醇缩合反应中的活性较低,而单金属氧化物和双金属氧化物具有较高的活性。以氧化镁为催化剂,对2-庚基环戊酮的选择性最高(52%)。
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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 Q3 CHEMISTRY, PHYSICAL Pub Date : 2020-05-01 DOI: 10.1177/1468678319891416
B. Abolpour, R. Shamsoddini
The reaction kinetics of carbon reduction of silica were investigated using thermodynamic concepts and by fitting to relevant models the experimental data obtained for this reduction using a thermogravimetric unit in the temperature range of 1566 to 1933 K. The results show that the only way to produce SiC in this reduction is the reaction of Si, SiO, or SiO2 at the surface or by diffusion of SiO inside the carbon particles while CO and CO2 have no direct effect on the process. The controlling step of this reduction at temperatures lower than 1750 K is the chemical gas–solid or solid–solid reaction at the surface of the carbon particles, while at higher temperatures, the rate of SiO diffusing inside the carbon particles controls the rate of this reduction.
用热力学概念研究了二氧化硅的碳还原反应动力学,并用热重仪在1566 ~ 1933 K的温度范围内对该还原反应的实验数据进行了拟合。结果表明,在此还原过程中,生成SiC的唯一途径是Si、SiO或SiO2在碳颗粒表面的反应或SiO在碳颗粒内部的扩散,而CO和CO2对该过程没有直接影响。在低于1750 K的温度下,碳颗粒表面的化学气固或固固反应是这一还原的控制步骤,而在较高温度下,碳颗粒内部SiO的扩散速度控制着这一还原的速度。
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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 Q3 CHEMISTRY, PHYSICAL Pub Date : 2020-05-01 DOI: 10.1177/1468678319888629
Korichi Smain, Aoudia Nacera, Benelmaddjat Hanane, Kaci Smina, Ousmaal Nafissa
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.
碳酸铀酰铵(NH4)4UO2(CO3)3是生产核燃料用UO2和U3O8陶瓷的重要原料。采用马弗炉、紫外可见分光光度计、气体吸附、汞孔隙度法、激光粒度法和光谱学等方法,研究了等温条件下碳酸铀酰铵在空气气氛下转化得到三氧化铀(U3O8)的热力学研究和动力学分析。制备样品的结构性质(比表面积、形貌、孔径、晶粒尺寸、种间孔隙度和种内孔隙度)和特征(铀含量和化学计量学)由物理化学表征估计。通过对实验数据的拟合估计了动力学参数。根据常规和等转化动力学模型计算活化能Ea、频率因子A和反应速率常数k,均在文献值范围内。常规模型和等转换模型的平均活化能分别为36.69和30.36 kJ mol−1。
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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 Q3 CHEMISTRY, PHYSICAL Pub Date : 2020-05-01 DOI: 10.1177/1468678320901622
Wei Ke, Guangjin Chen, Daoyi Chen
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.
尽管几十年来人们对天然气水合物和水合物勘探进行了广泛的研究,但水合物形成的反应动力学和成核机理仍未完全了解。在天然气水合物形成的早期阶段,可以认为是一个具有成核和初始生长的自催化动力学反应。本文建立了甲烷-丙烷水合物在等共压反应器中形成II型结构的反应动力学模型。该计算模型包括6个准元素反应的3个动态过程:(1)气体溶解到散装液体中;(2)开始成核的水合物前体的缓慢积累;(3)开始后水合物的快速自催化生长。模型采用FORTRAN编程,初始参数和速率常数由实验数据拟合得到。模拟表明,成核诱导的长度在很大程度上取决于低聚水合物前体的积累达到一个阈值。前驱体的缓慢积累是整个水合物形成的限速步骤,其转化为水合物颗粒对于快速的自催化反应至关重要。应用该模型,通过在模拟中指定不同初始量的前驱体或水合物种类,研究了水合物成核的记忆效应。预先存在的前驱体或水合物颗粒的存在可以促进成核阶段,缩短诱导时间,而不影响水合物的生长。计算模型与所进行的模拟提供了深入了解反应动力学和水合物形成的成核机理。
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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 Q3 CHEMISTRY, PHYSICAL Pub Date : 2020-05-01 DOI: 10.1177/1468678319887931
Niloofar Atashi, M. H. Peyrovi, N. Parsafard
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.
采用湿浸渍法制备了铂碳系催化剂,并对挥发性有机物甲苯进行了催化氧化试验。通过x射线衍射、x射线荧光、电感耦合等离子体-发射光谱、傅里叶变换红外、扫描电镜和N2吸附-脱附分析对所构建催化剂的结构进行了表征。结果表明,铂负载碳纳米管的催化活性最高(>99%),对CO2的选择性和稳定性最高(>99%)。转化率和选择性曲线表明,催化剂对挥发性有机化合物的去除率和转化为CO2的性能依次为:铂负载碳纳米管>铂负载石墨烯>铂负载活性炭>铂负载碳纳米纤维。在不同温度下,甲苯氧化动力学作为甲苯和氧分压的函数进行了评价。采用幂定律和Mars-van Krevelen两种动力学模型对反应进行了分析,并与实验数据进行了比较。Mars-van Krevelen模型比幂定律模型更适合于该反应,因为Mars-van Krevelen模型能更好地预测反应的行为。
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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 Q3 CHEMISTRY, PHYSICAL Pub Date : 2020-05-01 DOI: 10.1177/1468678319877643
Yunwu Yu, Lianjie Liang, Yunxue Liu, Chang-Wei Xu, Qing Wang, W. Niu, Changwei Liu
A novel method for preparing Ni2P/Al2O3(L) catalysts in an N2 atmosphere by decomposition of hypophosphites was proposed, and Ni2P/Al2O3(T) catalyst was synthesized by the temperature programmed reduction method in a H2 atmosphere for comparison. These prepared catalysts were washed with deionized water to remove impurities. The X-ray diffraction, N2-adsorption specific surface area measurements, CO uptake, and X-ray photoelectron spectroscopy were applied to characterize these catalysts. The activities of the Ni2P/Al2O3 catalysts prepared with the two different methods were tested in the dibenzothiophene hydrodesulfurization reaction.
提出了在N2气氛中分解次亚磷酸酯制备Ni2P/Al2O3(L)催化剂的新方法,并与在H2气氛中采用程序升温还原法制备Ni2P/Al2O3(T)催化剂进行了比较。用去离子水洗涤这些制备的催化剂以去除杂质。采用x射线衍射、n2吸附比表面积、CO吸收量和x射线光电子能谱对催化剂进行了表征。考察了两种方法制备的Ni2P/Al2O3催化剂在二苯并噻吩加氢脱硫反应中的活性。
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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 Q3 CHEMISTRY, PHYSICAL Pub Date : 2020-05-01 DOI: 10.1177/1468678319870327
Zhang Jiaying
A series of Ni–Fe/MCM-41 bimetallic catalysts and also Ni/MCM-41 and Fe/MCM-41 catalysts were prepared by the incipient-wetness impregnation method and tested for their activity for CO methanation in a continuous-flow microreactor. The results showed that the catalytic activities of the Ni–Fe/MCM-41 bimetallic catalysts were much higher than those of the Ni/MCM-41 and Fe/MCM-41 catalysts at low temperatures (200°C–325°C). The 10%Ni–5%Fe/MCM-41 catalyst showed the best activity with a CO conversion of almost 100% and a CH4 selectivity of 98% at 350°C under a pressure of 1.5 MPa with a 3:1 molar ratio of H2 to CO and a weight hourly space velocity of 12,000 mL h−1 g−1. The catalysts were characterized by N2 physisorption measurements, X-ray diffraction, and H2-temperature-programmed reduction. The results showed that the addition of Fe will lead to the formation of finer Ni particles and Ni–Fe alloy, which were the main reasons for the activity increase in the Ni–Fe/MCM-41 catalysts.
采用初湿浸渍法制备了一系列Ni - Fe/MCM-41双金属催化剂以及Ni/MCM-41和Fe/MCM-41双金属催化剂,并在连续流微反应器上对其CO甲烷化活性进行了测试。结果表明,Ni - Fe/MCM-41双金属催化剂在低温(200℃~ 325℃)下的催化活性远高于Ni/MCM-41和Fe/MCM-41催化剂。10%Ni-5%Fe /MCM-41催化剂在压力为1.5 MPa、H2与CO摩尔比为3:1、质量时空速为12,000 mL h−1 g−1、温度为350℃条件下,CO转化率接近100%,CH4选择性为98%。通过N2物理吸附、x射线衍射和h2程序升温还原对催化剂进行了表征。结果表明,Fe的加入使Ni - Fe/MCM-41催化剂的活性提高的主要原因是Ni - Fe/MCM-41催化剂的Ni颗粒和Ni - Fe合金的形成更细。
{"title":"Preparation of bimetallic Ni–Fe/MCM-41 catalysts and their catalytic activity for CO methanation","authors":"Zhang Jiaying","doi":"10.1177/1468678319870327","DOIUrl":"https://doi.org/10.1177/1468678319870327","url":null,"abstract":"A series of Ni–Fe/MCM-41 bimetallic catalysts and also Ni/MCM-41 and Fe/MCM-41 catalysts were prepared by the incipient-wetness impregnation method and tested for their activity for CO methanation in a continuous-flow microreactor. The results showed that the catalytic activities of the Ni–Fe/MCM-41 bimetallic catalysts were much higher than those of the Ni/MCM-41 and Fe/MCM-41 catalysts at low temperatures (200°C–325°C). The 10%Ni–5%Fe/MCM-41 catalyst showed the best activity with a CO conversion of almost 100% and a CH4 selectivity of 98% at 350°C under a pressure of 1.5 MPa with a 3:1 molar ratio of H2 to CO and a weight hourly space velocity of 12,000 mL h−1 g−1. The catalysts were characterized by N2 physisorption measurements, X-ray diffraction, and H2-temperature-programmed reduction. The results showed that the addition of Fe will lead to the formation of finer Ni particles and Ni–Fe alloy, which were the main reasons for the activity increase in the Ni–Fe/MCM-41 catalysts.","PeriodicalId":20859,"journal":{"name":"Progress in Reaction Kinetics and Mechanism","volume":"16 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87874205","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
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 Q3 CHEMISTRY, PHYSICAL Pub Date : 2020-02-01 DOI: 10.1177/1468678319899252
V. Saheb, Aidin Bahadori
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.
对1,3,5-三氧环醚和1,4-二氧环醚在OH自由基作用下的双分子吸氢反应动力学进行了理论研究。考虑了1,3,5-三氧环和1,4-二氧环的轴位和平位吸氢。利用M06-2X水平的密度泛函理论,结合MG3S基集,对结构进行了优化,计算了包括反应物、氢键配合物、过渡态和产物在内的各驻点的能量、振动频率和转动惯量。在CBS-QB3水平上对优化点进行单点能量计算。计算表明,由于羟基自由基与环醚氧原子之间的氢键作用,标题反应通过较强的氢键配合物进行。采用双过渡态模型(内紧过渡态和外松过渡态)计算抽氢速率系数。为了便于比较,采用传统的过渡态理论计算了速率系数,并考虑了紧过渡态。研究发现,当反应通过相对能量高于反应物的内过渡态进行时,传统的过渡态理论低估了反应速率系数。
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引用次数: 1
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 Q3 CHEMISTRY, PHYSICAL Pub Date : 2020-01-01 DOI: 10.1177/1468678319825732
Hongyi Li, Yubo Ma
A series of magnetically separable catalysts based on Ru–Ni bimetallic compounds supported on Fe3O4 nanoparticles was prepared by the co-precipitation method. These catalysts were evaluated for diformyltricyclodecanes hydrogenation reactions, achieving 97% tricyclodecanedimethylol selectivity at 98% diformyltricyclodecanes conversion under mild conditions. The catalyst could be easily recovered by using the magnetic property of the iron oxide support. The catalysts were characterized with X-ray photoelectron spectroscopy, X-ray diffraction, and temperature-programmed reduction. These complementary characterization results suggested that the superior catalytic activity may be derived from the delicate synergy between Ru and Ni species.
采用共沉淀法制备了一系列以Fe3O4纳米颗粒为载体的Ru-Ni双金属化合物磁性可分离催化剂。对这些催化剂进行了二甲酰基三环癸烷加氢反应的评价,在温和条件下,二甲酰基三环癸烷的转化率为98%,三环癸烷的选择性为97%。利用氧化铁载体的磁性可以很容易地回收催化剂。用x射线光电子能谱、x射线衍射和程序升温还原对催化剂进行了表征。这些互补的表征结果表明,优越的催化活性可能源于Ru和Ni之间的微妙协同作用。
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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 Q3 CHEMISTRY, PHYSICAL Pub Date : 2020-01-01 DOI: 10.1177/1468678319897724
Haiqiang Zhao, Hua Song, Lele Zhao, Feng Li
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.
采用两种不同的硫酸盐浸渍方法成功制备了La-Ni-S2O82 - / ZrO2-Al2O3催化剂,并通过x射线衍射、Brunauer-Emmett-Teller分析、傅立叶变换红外光谱、吡啶吸附红外光谱和x射线光电子能谱技术对催化剂的理化性质进行了表征。以正戊烷异构化为探针反应,在固定床流动反应器中评价了催化活性。与传统浸渍法制备的La-Ni-S2O82 - / ZrO2-Al2O3-I催化剂相比,初湿浸渍法制备的La-Ni-S2O82 - / ZrO2-Al2O3-W催化剂具有更高的孔容、孔径、硫含量和更强的Brønsted酸位。在3000 min内,La-Ni-S2O82 - / ZrO2-Al2O3-W的催化活性保持在56%左右,异戊烷选择性为88%,稳定性远高于La-Ni-S2O82 - / ZrO2-Al2O3-I。这可以归结为:(1)La-Ni-S2O82 - / ZrO2-Al2O3-W具有较大的孔径和孔体积,可以在很大程度上抑制碳沉积;(2)La-Ni-S2O82 - / ZrO2-Al2O3-W具有更多且更强的Brønsted酸位,保证了在反应过程中为异构化提供足够的酸位。
{"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":"1 1","pages":""},"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
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Progress in Reaction Kinetics and Mechanism
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