KOREAN JOURNAL OF CHEMICAL ENGINEERING
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2016
·Vol. 33
·期 7
·2097-2106
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IF 1.408
Bai Ting,Zhang Xin,Liu Xiling,Chen Tengfei,Fan Wentao
A series of HZSM-5 catalysts were synthesized by different methods. The physicochemical properties of the HZSM-5 catalysts were characterized by XRD, SEM, N2 isothermal adsorption-desorption, NH3-TPD, Py-IR and TGA, respectively. The results indicated that different preparation conditions lead to different morphologies, textures and the distribution of acid sites. The nanosized HZSM-5 catalysts exhibited better catalytic reactivity and coke capacity than the micro-sized HZSM-5 because nanosized HZSM-5 had larger specific surface area, higher pore volume, more exposed channels and more accessible acid sites. The large particles of NZ-3 in a reasonable range and the smooth surface were conducive to product diffusion; therefore, NZ-3 exhibited higher specific propylene yield and stability than the other nanosized catalysts. The moderate density and distribution of acid sites on NZ-3 also favored the formation of propylene.
研究领域:
化学工程
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催化科学
✓ 已验证
DOI
高影响因子
Catalysts
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2023
·Vol. 13
·期 3
·640
·
IF 3.9
Cong Wang,Gang Li,Hongchen Guo
MOFs have attracted widespread attention in the field of catalytic ethylene dimerization. Compared with post-synthetic modification, ion exchange and other methods to introduce external active centers, the direct use of MOF materials as catalysts is still the most convenient and prospective. Herein, the NiBTCs are synthesized using a one-pot method in two kinds of solvent and characterized by XRD, FT–IR, ICP–OES, XPS, TGA and N2physical adsorption. After treatment at 150 °C, the catalytic activities of both materials in ethylene dimerization are up to 470.9, and 647.0 gpro./(gcat.·h) and the selectivity of 1-butene in all products could reach 83.2% and 81.7%, respectively. Stability testing of the catalysts demonstrated that they do not decompose during the reaction, but their reuse performance is degraded. In addition, a probable Cossee–Arlman–type mechanism is proposed. The NiBTCs are shown to have superior catalytic performance in ethylene dimerization compared to employing Ni(pyz)2Cl2or α–Ni(im)2as catalysts.Keywords:ethylene dimerization;NiBTCs;MOFs;1-butene
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
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2014
·
IF 3.679
Yuming Cui,Na Liu,Yifen Xia,Jiangang Lv,Sujuan Zheng,Nianhua Xue,Luming Peng,Xuefeng Guo,Weiping Ding
1-Butene, abundant but inexpensive in industry, can be used to produce more valuable propene and ethene through the well-known metathesis reaction. In terms of catalyst system of molybdena, controlling the interaction between the molybdena and the support is quite crucial. A special support, i.e., well-shaped one-dimensional γ-Al 2 O 3 with uniform diameters of ∼10 nm and lengths of ∼100 nm, has been synthesized via oleylamine-assisted hydrothermal method. The molybdenum oxides are well controlled in sizes of moderate aggregation suitable for 1-butene metathesis with a fairly high rate of propene production (38.9 × 10 −9 mol m −2 s −1 , 30 mol% yield in a single pass) under mild conditions. The status of MoO x species in the catalyst has been investigated by solid state 29 Si MAS NMR, Raman, UV–vis, H 2 -TPR and NH 3 -TPD techniques. The catalyst, highly stable after twelve times of regeneration, is important for practical utilization for the metathesis reactions.
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Tingting Lu,Yufei Sun,Zhiwei Wang,Shuo Zhang,Yongsheng Yang,Hongdan Zhang,Peng Cheng,Zhen Zhao
A facile and effective post-treatment route has been systematically applied for the preparation of hierarchical zeolites SAPO-18 using oxalic acid or sodium citrate etching solution. The influence of acidic or alkaline post-treatment on the relative crystallinity, morphology, chemical composition, pore characteristics, and acidity of a series of zeolites SAPO-18 was investigated by X-ray diffraction, scanning and transmission electron microscopy, X-ray fluorescence spectroscopy, nitrogen adsorption–desorption, temperature-programmed desorption of ammonia, and solid-state magic angle spinning nuclear magnetic resonance spectroscopy experiments. Post-treatment led to an increase in mesoporosity by widening the micropores, but a decrease in the acid strength of zeolite SAPO-18 samples. The effects of mesoporosity and acidity on the catalytic cracking performance of zeolite SAPO-18 samples were studied. The hierarchical zeolite SAPO-18 sample post-treated by alkaline sodium citrate solution with suitable concentration exhibited better catalytic conversion and improved light olefin selectivity in cracking of 1-butene.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2019
·
IF 5.128
Lulu Yan,Tingting Duan,Tingting Huang,Bingbing Zhao,Yu Fan
This article proposes a novel strategy for producing highly dispersed H 3 PW 12 O 40 (HPW) on metal-organic frameworks (MOFs) via the anchoring action of amino groups originating from 2-amino terephthalic acid (APTA) in the MOF ligand. Under this method, amino groups are introduced into the linker of UiO-66 materials through a one-pot synthesis to disperse supported HPW, which has a negligible impact on the crystal structure of UiO-66. The acidic densities in the HPW/UiO-66 catalysts are effectively modified by adjusting the molar APTA/PTA (terephthalic acid) ratio in the mixed ligand and HPW loading. Consequently, the dispersion and stability of supported HPW are significantly enhanced, which make the as-prepared catalyst with 40 wt% of HPW present superior sec -butyl acetate (SBAC) yield (38.6 wt%) and selectivity (98 wt%) for the direct esterification of olefins. This strategy provides a new approach for preparing supported HPW with high dispersion and stability to be applied in olefin esterification.
研究领域:
化学工程
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催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2017
·
IF 0
Xiang Li,Kaixuan Zhang,Li Qin,Haihong Ma
The kinetic studies of hydroformylation of 1-butene to produce pentanal were investigated by using Rh/PPh 3 complex as homogeneous catalyst, valeraldehyde and its polycondensates as solvent. The experiment was carried out on small hydroformylation continuous reaction installation. The effects of reaction temperature, the concentration of 1-butene, the partial pressure of CO or H 2 and the concentration of rhodium of catalyst on the reaction rate were studied. Based on the reaction mechanism of hydroformylation and the latest research results of hydroformylation kinetics, the kinetic equation suitable for the hydroformylation of 1-butene was established. The parameters of the kinetic equation were regressed and verified with the experimental data. The relationship between the normal/isomeric ratio of pentanal and the partial pressure of CO was further explored.
研究领域:
化学工程
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催化化学
✓ 已验证
产品关联
DOI
RSC Advances
·
2023
·Vol. 13
·期 23
·15934-15941
·
IF 3.9
Xiaoping Chen,Xianfei Wang,Wei Liu,Hui Tian,Yupeng Du,Haisheng Wei,Linsheng Tang
1-Butene, as one of the widely used chemical raw materials, can be produced by the double bond isomerization of 2-butene. However, the current yield of the isomerization reaction is only up to 20% or so. It is therefore an urgent issue to develop novel catalysts with higher performances. In this work, a high-activity ZrO2@C catalyst that is derived from UiO-66(Zr) is fabricated. The catalyst is prepared by calcining the precursor UiO-66(Zr) at high temperature in nitrogen, and characterized by XRD, TG, BET, SEM/TEM, XPS and NH3-TPD. The results demonstrate that the calcination temperature has significant influences on the catalyst structure and performance. Regarding the catalyst ZrO2@C-500, the selectivity and yield of 1-butene are 94.0% and 35.1%, respectively. The high performance is due to multiple aspects, including the inherited octahedral morphology from parent UiO-66(Zr), suitable medium-strong acidic active sites and high surface area. The present work will lead to a better understanding of the ZrO2@C catalyst and guide the rational design of high-activity catalysts for the double bond isomerization of 2-butene to 1-butene.
研究领域:
化学工程
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催化材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials
·
2020
·Vol. 13
·期 3
·755
·
IF 3.057
Lingfei Li,Qiu Sun,Xiangqun Chen,Yongjun Xu,Zhaohua Jiang
In this work, poly(1-butene) (PB-1) composite films with multi-walled carbon nanotubes (MWCNT) were prepared by a solution casting method. The relationship between the dielectric properties and the crystal transformation process of the films was investigated. It was indicated that there were two crystal forms of I and II of PB-1 during the solution crystallization process. With the prolongation of the phase transition time, form II was converted into form I. The addition of the conductive filler (MWCNT) accelerated the rate of phase transformation and changed the nucleation mode of PB-1. The presence of crystal form I in the system increased the breakdown strength and the dielectric constant of the films and reduced the dielectric loss, with better stability. In addition, the dielectric constant and the dielectric loss of the MWCNT/PB-1 composite films increased with the addition of MWCNT, due to the interfacial polarization between MWCNT and PB-1 matrix. When the mass fraction of the MWCNT was 1.0%, the composite film had a dielectric constant of 43.9 at 25 °C and 103Hz, which was 20 times that of the original film.Keywords:poly(1-butene);multi-walled carbon nanotubes;solution crystallization;dielectric properties;breakdown strength
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Nano Materials
·
2018
·
IF 0
Yanping Hu,Ying Zhang,Yang Han,Donghai Sheng,Dongming Shan,Xiangyun Liu,Achao Cheng
Ultrathin nickel-based metal–organic framework nanosheets (Ni-UMOFNs) were formed from NiCl2·6H2O and benzene-1,4-dicarboxylate through a sonication exfoliation method. In Ni-UMOFNs, the Ni atoms are octahedrally coordinated by six O atoms to form pseudo-octahedra which are further edge/corner connected with each other to form 2D layers separated by benzene-1,4-dicarboxylate linkers. On the Ni-UMOFN surfaces, Ni centers are partially five coordinated owing to the termination of benzene-1,4-dicarboxylate ligands, and these coordinated unsaturated metal sites can be used as catalytic active sites. In this work, Ni-UMOFNs were utilized as ethylene dimerization catalysts in the presence of an alkylaluminum cocatalyst for the first time. The Ni-UMOFN catalytic system showed moderate catalytic activity but high selectivity to 1-butene up to 92.8% under optimal conditions. The optimal Ni-UMOFN catalyst can be reused at least four times without considerable loss in the catalytic activity and selectivity to 1-butene. Extraordinarily, the outstanding level of reusable property is due to continuous exposure of fresh unsaturated metal active sites when the original metal centers on the catalyst surface are used and exfoliated, just like a snake’s molting.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2018
·Vol. 25
·期 24
·24241-24252
·
IF 2.8
Zhu Jianqiang,Tsona Narcisse T.,Du Lin
Chloroalkenes are among the important anthropogenic organic compounds emitted in the atmosphere as a result of their wide use in synthetic processes in industry. Despite their well-known adverse effects on human health and air quality, the chemistry of these chloroalkenes remains poorly explored. In this work, reactions of 4-chloro-1-butene (CBE), a representative example of chloroalkenes, with O 3 , OH, NO 3 , and Cl are investigated in a 100-L Teflon reaction chamber equipped with gas chromatography-flame ionization detector (GC-FID). The absolute rate method was used for the reaction with O 3 while the relative rate method was used for reactions with OH, NO 3 , and Cl. The following rate constants were obtained at room temperature (298 ± 2) K and atmospheric pressure: (3.96 ± 0.43) × 10 −18 , (2.63 ± 0.96) × 10 −11 , (4.48 ± 1.23) × 10 −15 , and (2.35 ± 0.90) × 10 −10 cm 3 molecule −1 s −1 , for reactions with O 3 , OH, NO 3 , and Cl, respectively. Atmospheric lifetimes of CBE calculated from rate constants of the different reactions obtained in this work showed that reaction with OH is the main loss process for CBE, while in coastal areas and in the marine boundary layer, the CBE loss by Cl reaction becomes important. Estimation of the value of the photochemical ozone creation potential (POCP) indicated that CBE has a large ozone formation potential. The present work underlines the need for further studies on the atmospheric chemistry of chlorinated VOCs.
研究领域:
大气化学
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环境科学
·
有机化学
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Yang Li,Chunyan Ma,Hongling Yang,Zhongshen Zhang,Xin Zhang,Nanli Qiao,Junhui Wang,Zhengping Hao
The traditional reaction temperatures of 1-butene isomerization to 2-butene tend to above 100 °C, while here we report the unique catalytic performance of a Pd loaded silica nanospheres catalyst for 1-butene double-bond-shift isomerization at room temperature and showed 2-butene yield of 37.0%. Furthermore, the introduction of O 2 into the reaction mixture dramatically improved the yield efficiency to 57.2% without the formation of by-product CO 2 . The reaction process is proved that the ratio of trans -2-butene to cis -2-butene in the final product was determined by the trans : cis ratio of the butenylcarbenium ion intermediate, and the ratio of trans -2-butene to cis -2-butene decreased with the increasing reaction temperature. Unlike other palladium catalyst systems, Pd 0 nanoparticles were proved to act as catalytic active sites, and their oxidation and aggregation resulted in a decrease in activity. Most importantly, the catalyst acidity affected the catalytic performance, which provides theoretical basis for the choice of catalysts.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2021
·Vol. 13
·期 2
·285
·
IF 4.329
Lingfei Li,Qiu Sun,Xiangqun Chen,Zhaohua Jiang,Yongjun Xu
The low dielectric constant of the nonpolar polymer poly(1-butene) (PB-1) limits its application as a diaphragm element in energy storage capacitors. In this work, Ba(Zr0.2Ti0.8)O3-coated multiwalled carbon nanotubes (BZT@MWCNTs) were first prepared by using the sol–gel hydrothermal method and then modified with polydopamine (PDA) via noncovalent polymerization. Finally, PB-1 matrix composite films filled with PDA-modified BZT@MWCNTs nanoparticles were fabricated through a solution-casting method. Results indicated that the PDA-modified BZT@MWCNTs had good dispersion and binding force in the PB-1 matrix. These characteristics improved the dielectric and energy storage performances of the films. Specifically, the PDA-modified 10 vol% BZT@ 0.5 vol% MWCNTs/PB-1 composite film exhibited the best dielectric performance. At 1 kHz, the dielectric constant of this film was 25.43, which was 12.7 times that of pure PB-1 films. Moreover, its dielectric loss was 0.0077. Furthermore, under the weak electric field of 210 MV·m−1, the highest energy density of the PDA-modified 10 vol% BZT@ 0.5 vol% MWCNTs/PB-1 composite film was 4.57 J·cm−3, which was over 3.5 times that of PB-1 film (≈1.3 J·cm−3at 388 MV·m−1).Keywords:sol–gel hydrothermal method;PDA-modified BZT@MWCNTs nanoparticles;dielectric performance;synergistic effect
研究领域:
材料科学
·
能源存储
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）