APPLIED CATALYSIS A-GENERAL
·
2024
·
IF 4.7
Lihong Ding,Xiuliang Sun,Chongpin Huang,Jianwei Li,Biaohua Chen
Cumyl hydroperoxide (CHP) is an important intermediate in phenol/acetone production; however, its long reaction time and low yield remain industrial challenges. In this study, an active and promising catalyst combination—NHPI + BmimBr ionic liquid (IL)—was developed for cumene oxidation under solvent-, transition-metal-salt-, and CHP-initiator-free conditions, which exhibited a synergistic catalytic effect and excellent catalytic performance. The cumene oxidation rate was accelerated by 33.3 %, leading to the rapid synthesis of a significant amount of the target product, CHP. DFT calculations demonstrated that NHPI undergoes hydrogen atom abstraction reaction through its interaction with BmimBr, forming PINO and carbene-Br radicals that can extract hydrogen. Additionally, EPR analysis demonstrated that both radicals are involved in the reaction. The nature of the synergistic effect was confirmed using theoretical and experimental approaches. The proposed catalyst eliminates the requirement of an initiator for IL and NHPI application, paving the way for the efficient production of CHP without solvents or initiators.
研究领域:
化学工程
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2024
·Vol. 14
·期 5
·288
·
IF 3.8
Tianyun Wang,Yingjie Guan,Haidan Wu,Zhaojie Su,Jianguo Zhuang,Siyan Yan,Xuedong Zhu,Fan Yang
Utilizing carbon dioxide as a carbon source for the synthesis of olefins and aromatics has emerged as one of the most practical methods for CO2reduction. In this study, an improved selectivity of 85% for targeting products (ethylbenzene and propylbenzene) is achieved with a benzene conversion of 16.8% by coupling the hydrogenation of carbon dioxide to olefins over the bifunctional catalyst “Oxide-Zeolite” (OX-ZEO) and the alkylation of benzene with olefins over ZSM-5. In addition to investigating the influence of SAPO-34 and ZSM-5 zeolite acidity on product distribution, catalyst deactivation due to coke formation is addressed by modifying both molecular sieves to be hierarchical to extend the catalyst lifespan. Even after 100 h of operation at 400 °C, the catalysts maintained over 80% selectivity towards the target products, with benzene conversion over 14.2%. Furthermore, the pathway of propylbenzene formation is demonstrated through simple experimental design, revealing that the surface Brønsted acid sites of SAPO-34 serve as its primary formation sites. This provides a novel perspective for further investigation of the reaction network.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
COMBUSTION AND FLAME
·
2019
·
IF 4.12
Dong-Xu Tian,Yue-Xi Liu,Bing-Yin Wang,Chuang-Chuang Cao,Zhong-Kai Liu,Yi-Tong Zhai,Yan Zhang,Jiu-Zhong Yang,Zhen-Yu Tian
Pyrolysis study of iso-propylbenzene (IPB) at 30 and 760 torr was carried out by using synchrotron photoionization and molecular beam mass spectrometry techniques. 0.5%IPB was diluted by helium and heated to 798–1148 K in a flow tube. Styrene was the most abundant aromatic intermediate at both pressures. Several polycyclic aromatics were only observed at 760 torr, such as 2-ethenyl-1, 4-dimethyl-benzene, fluorene, anthracene , phenanthrene, 2-methyl-anthracene and pyrene, while fulvene, 1, 3-cyclohexadiene, and 5-ethenylidene-1, 3-cyclopentadiene were only detected at 30 torr. A detail mechanism involving 306 species and 1990 reactions was developed by updating ipso-addition and unimolecular dissociation reactions of IPB as well as reactions related to styrene, indene and naphthalene . The mechanism could predict the pyrolysis of IPB and production of other intermediates well. Rate-of-production analysis shows that the formations of 2-phenethyl, 1-iso-phenylpropyl and 2-iso-phenylpropyl radicals are the main consumption reactions of IPB independent of pressure. Sensitivity analysis indicates that the unimolecular dissociation of IPB forming 2-phenethyl radical is the most significant promoting reaction at both pressures. H-abstraction reaction forming 1-iso-phenylpropyl radical tends to play a significant inhibiting effect on IPB consumption at 30 torr, while the most inhibiting reaction is self-combination of methyl radicals at 760 torr. Compared to n-propylbenzene experiments reported by Liu et al. (Combustion and Flame, 191 (2018) 53–65) and Yuan et al. (Combustion and Flame,186 (2017) 178–192.), IPB tends to produce larger quantities of benzene, styrene and indene under pyrolysis and oxidation conditions. These results will improve the understanding of the combustion and soot formation of IPB as a potential aviation surrogate fuel.
研究领域:
化学动力学
·
燃烧科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2015
·
IF 2.679
Hao Li,Shuqian Xia,Meng Wu,Peisheng Ma
Developing value-added chemicals from pyrolysis oil has been gaining increasing attention. Thus effective separation and purification of the pyrolysis oil are important and the phase equilibrium data are essential for the design and simulation of the processes. In this study, isobaric vapour–liquid equilibrium (VLE) for the two binary mixtures (butyl acetate + anisole) and (butyl acetate + guaiacol) have been determined at 101.33 kPa, a knowledge of which is essential for the separation of methoxy aromatic compounds (anisole and guaiacol) from biomass fast pyrolysis oil using butyl acetate as a solvent. All the experimental values were confirmed to be thermodynamically consistent using the van Ness method. The NRTL, UNIQUAC, and Wilson activity coefficient models were applied to regress the experimental values. The calculated results agreed well with the measured values. Furthermore, the results were calculated by the UNIFAC (Do) method (modified UNIFAC model) in which aromatic methoxyl is treated as a group (ACOCH 3 ). The new interaction parameter (ACOCH 3 –CH 3 COO) was obtained and proved to be reliable. Based on the preceding results, a feasible separation process for the ternary mixture (butyl acetate + anisole + guaiacol) has been designed to obtain the required products.
研究领域:
化学工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Fang-Yu Zhan,Jian-Gang Guo,Xin-Ran Zhang,Xin-Liang Li
Measuring and understanding interaction forces between hydroxylated graphene (G-OH) and aromatic compounds is significant for the applications of composites based on G-OH, such as 3D graphene derivatives preparation and wastewater treatment. In this research, the adsorption/separation mechanical behavior of anisole on graphene and G-OH surfaces was investigated by atomic force microscopy (AFM) experiments and molecular dynamics (MD) simulations. The adsorption and separation curves of anisole on graphene and G-OH surfaces were obtained by experiments, and the adhesive forces of a single anisole were achieved by the Poisson statistics method. It is found that there are two types of adhesive forces between anisole and G-OH. For graphene and anisole, two extreme values are got by the adsorption and separation processes, and the adhesive force obtained by the separation process is approximately equal to one type of adhesive force between anisole and G-OH. Furthermore, MD simulation results reveal that the maximum adhesive force of anisole on the G-OH surface depends on its position relative to the hydroxyl group, and anisole has a greater affinity near the hydroxyl group. The position and planar angle of the anisole conformations cause the difference in adhesive forces.
研究领域:
材料科学
·
表面化学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2016
·
IF 2.567
Yong Chen,Hong-yan Song,Ying-zhou Lu,Hong Meng,Chun-xi Li,Zhi-gang Lei,Biao-hua Chen
For the deep desulfurization of fuel oil, adsorptive desulfurization (ADS) and oxidative desulfurization (ODS) may be the most viable alternatives to the conventional HDS process. In this work, a highly cross-linked vanadate based polyionic liquid (V-PIL) was synthesized by reacting poly(vinylimidazole) (PVIM) with peroxy-vanadic acid. The as-prepared V-PIL is mesoporous with specific area of 163 m2·g–1 and good adsorptivity for the oxidized sulfur compounds. Further, it can efficiently catalyze the oxidation of dibenzothiophene and benzothiophene with cumene hydroperoxide (CHP), achieving a unified desulfurization processes of ODS and ADS. Its catalytic activity and reusability is superior to the supported vanadate catalysts, e.g. V2O5@active carbon and V2O5@zeolite. The desulfurization capacity of V-PIL is 99% in the first run under specified conditions, i.e. stirring 4 h at 323 K for 500 ppmS DBT oil, with CHP/S being 4 in mole ratio and 3 wt % V-PIL with respect to oil. And over 80% of its desulfurization capacity can be retained after five successive uses without regeneration under the above conditions. The V-PIL may represent a new type of bulk catalyst with potential application considering its rich porosity, good dispersion, accessible catalytic sites, and no soluble loss of the bonded vanadates in the recycling uses.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Chemistry
·
2020
·
IF 1.79
Xiaojuan Wu,Liping Chen,Guoning Rao,Wanghua Chen,Ruili Yin
To reduce the fire and explosion accident of dicumyl peroxide (DCP) in experiment and production, the thermal hazards of DCP and 40% mass content DCP in ethyl benzene (40% DCP) have been studied by the differential scanning calorimeter (DSC) and the accelerating rate calorimeter (ARC) in this paper. DSC experiment showed that ethyl benzene has no effect on the characteristic parameters of thermal decomposition of DCP, such as the temperature of the exothermic peak (Tpeak) and the decomposition energy (Ea), and the thermal decomposition reaction of 40% DCP followed the one-step reaction principle. ARC experiment showed that with the increase of inertia factor (Φ), the measured initial decomposition temperature (Ton) would be higher and the caculated Ea and pre-exponential factor (A) would be greater. It was also proved that after modification of Φ, TD24 was relatively consistent near Ton, but different at higher temperatures. Fisher's correction method was used to verify the necessity of consistency between experimental conditions and prediction conditions.
研究领域:
化学工程
·
安全科学
✓ 已验证
DOI
高影响因子
Polymers
·
2024
·Vol. 16
·期 5
·676
·
IF 4.7
Linting Di,Chenyuan Qin,Wenying Wang,Anping Huang,Fuqing Wei,Huifang Xu,Shiyuan Yang
To investigate the influence of the crosslinked polyethylene (XLPE) structure on electrical performance, various analytical methods were employed to study polyethylene structures with different degrees of crosslinking. Dynamic rheological analysis was conducted to determine material shear viscosity, dynamic viscosity, storage modulus (G′), loss modulus (G″), and other rheological parameters. Additionally, the electrical performance of the material was analyzed by studying the phenomenon of space charge accumulation under direct current voltage. The results indicate that with an increasing mass fraction of the crosslinking agent, the crosslink density of crosslinked polyethylene initially increases and then decreases. When the dicumyl peroxide (DCP) content exceeds 1.0 wt.%, there is an accumulation of like-polarity space charges. The best rheological processing performance of crosslinked polyethylene is observed when the DCP content is in the range of 1.0–1.5 wt.%.
研究领域:
材料科学
·
电气工程
✓ 已验证
DOI
PubMed
高影响因子
THERMOCHIMICA ACTA
·
2018
·
IF 2.189
Shunyao Wang,Xu Peng,Huabo Li,Zichao Guo,Liping Chen,Wanghua Chen
Cumene hydroperoxide (CHP) is prone to thermal decomposition in chemical industry, but there are few reports on the related phenomena in the reactor when decomposition occurs. In order to reveal the complex phenomena of fluid-solid coupled heat transfer, two-phase flow and multi-phase chemical reaction in the CHP decomposition, computational fluid dynamics (CFD) approach was applied to simulate the decomposition of CHP with different mass in a closed pressure vessel. Based on a known reaction scheme and the kinetics evaluated from differential scanning calorimeter (DSC) results, a comprehensive CFD model of CHP decomposition was created. As a result, detailed information on the reaction course was obtained, and distribution of temperature, pressure, reaction rate, and flow velocity in the vessel were also investigated. Finally, closed pressure vessel tests (CPVT) were conducted to verify the validity of the CFD model. This work is conducive to deeply understand the thermal decomposition and reactive hazards assessment of CHP.
研究领域:
化学工程
·
安全科学
✓ 已验证
DOI
高影响因子
KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2022
·Vol. 39
·期 1
·96-108
·
IF 3.146
Zeng Xingye,Adesina Adeyemo,Li Ping,Wang Hanlu,Zhou Rujin
Ti-containing Mobil composition of matter-twenty-two (Ti-MWW) zeolite was prepared via a two-step post-synthesis process and then characterized by X-ray fluorescence, nitrogen adsorption-desorption isotherms, Fourier transform infrared absorption spectra, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectra. These results indicate that the textural properties of MWW were well preserved after acid treatment and incorporation of titanium. An adsorptive-oxidative desulfurization (AODS) system was successfully developed on the basis of a model oil containing dibenzothiophene (DBT) with the as-prepared Ti-MWW being the catalyst and adsorbent and cumene hydroperoxide (CHP) being the oxidant. The parameters influencing the desulfurization performance were systematically investigated. These parameters include the Ti-MWW dosage, the reaction temperature, the stirring speed, the molar ratio of CHP to DBT and the additions of olefins and aromatics to the system. The conversion rate of DBT reached 99.6% via the catalytic oxidation process and the turnover frequency was 40.1 h −1 . Meanwhile, the oxidation products of DBT were removed by Ti-MWW adsorption. The recycling and regeneration performance of Ti-MWW were also investigated, and the DBT conversion reached 99.5% using the regenerated Ti-MWW. This work provides useful information for the construction of solvent-free oxidative desulfurization systems using a zeolite.
研究领域:
化学工程
·
环境科学
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 136
·期 34
·47896
·
IF 2.188
Changjie Yin,Qiuyu Zhang,Zhuorui Zhang,Chengyuan Zhu,Jianxun Liu
The emulsion free-radical copolymerization of vinyl triethoxysilane (VTES) with styrene (St) and butadiene (Bd) was initiated by cumene hydroperoxide and ferrous sulfate at 0 °C. The effects of VTES on the copolymerization conversion, reaction time, gel content, latex particle size, thermal stability, and mechanical properties were thoroughly investigated. The success of this reaction was confirmed by the peaks attributed to both Si─O─Si groups at 1065 cm −1 and the Si─O─C bond at 1046 cm −1 . A kinetics analysis showed that the conversion decreased with increasing VTES mass in the monomer feed. Compared with that in the St–Bd copolymer, the latex particle size increased slightly with increasing VTES mass. The Mooney viscosity and gel content results show that a large fraction of precrosslinking molecular chains was formed in the rubber particles. The thermogravimetric analysis results indicate that the thermal stability of the copolymers increased with increasing VTES concentration. The 300% modulus and tensile strength of the St–Bd–VTES copolymer increased with the mass of VTES at first and then decreased after 3 phr VTES, whereas the elongation at break decreased with increasing VTES mass. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47896.
研究领域:
高分子化学
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
POLYMER
·
2018
·
IF 3.483
Yue Liu,Qinglong Zhang,Jiachun Feng
Poly(vinyl alcohol) (PVA) based dual-stimuli responsive shape memory composites were fabricated via a feasible reactive melt mixing with certain content of polyethylene (PE) and crosslinker dicumyl peroxide (DCP). It is found that PE plays many important roles in this method. Firstly, the melting processability of PVA can be improved markedly by skillfully utilizing the excellent flowability and crosslinking heat of PE. Secondly, the PVA composites achieve excellent water/heat dual-induced shape memory property by utilizing PE as fixing domain and heat responsive switching domain and utilizing PVA as water responsive switching domain meanwhile. The fixing ratio is nearly 100% and recovery ratio can reach 90% for both water and heat responsive shape memory. This artful fabricating method achieved the aim of improving the melting processability of PVA and endowing the composites dual-responsive shape memory property simultaneously only by utilizing PE, which is interesting and promising for the development of PVA in the industry application. It shows considerable prospect for PVA composites and their industry application.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）