资源类型

期刊论文 25

年份

2023 6

2022 2

2021 4

2017 1

2014 2

2013 2

2010 2

2009 2

2008 1

2007 2

展开 ︾

关键词

光催化 1

共混膜 1

杂多酸 1

油水分离 1

浸没沉淀 1

石墨相氮化碳 1

聚(乙烯-乙烯醇) 1

聚乙烯吡咯烷酮 1

苯甲醛 1

展开 ︾

检索范围:

排序: 展示方式:

Effects of ancillary ligands in acceptorless benzyl alcohol dehydrogenation mediated by phosphine-free

《化学科学与工程前沿(英文)》 2023年 第17卷 第3期   页码 314-325 doi: 10.1007/s11705-022-2219-2

摘要: Acceptorless alcohol dehydrogenation stands out as one of the most promising strategies in hydrogen storage technologies. Among various catalytic systems for this reaction, cost-effective molecular catalysts using phosphine-free ligands have gained considerable attention. However, the central challenge for using non-precious metals is to overcome the propensity of reacting by one-electron pathway. Herein, we synthesized a phosphine-free η5-C5Me5-Co complex by using the metal–ligand cooperative strategy and compared its activity with analogous catalysts toward acceptorless alcohol dehydrogenation. The catalyst showed excellent performance with a turnover number of 130.4 and a selectivity close to 100%. The improved performance among the class of η5-C5Me5-Co complexes could be attributed to the more accessible Co center and its cooperation with the redox-active ligand. To further study the systematic structure-activity relationship, we investigated the electronic structures of η5-C5Me5-Co complexes by a set of characterizations. The results showed that the redox-active ligand has a significant influence on the η5-C5Me5-Co moiety. In the meantime, the proximal O/OH group is beneficial for shuttling protons. For the catalytic cycle, two dehydrogenation scenarios were interrogated through density functional theory, and the result suggested that the outer-sphere pathway was preferred. The formation of a dihydrogen complex was the rate-determining step with a ΔG value of 16.9 kcal∙mol‒1. The electron population demonstrated that the η5-C5Me5 ligand played a key role in stabilizing transition states during dehydrogenation steps. This work identified the roles of vital ligand components to boost catalytic performance and offered rationales for designing metal–ligand cooperative nonprecious metal complexes.

关键词: acceptorless alcohol dehydrogenation     η5-C5Me5-Co     metal–ligand cooperation     theoretical calculation    

Insights into carbon-based materials for catalytic dehydrogenation of low-carbon alkanes and ethylbenzene

《化学科学与工程前沿(英文)》 2023年 第17卷 第11期   页码 1623-1648 doi: 10.1007/s11705-023-2328-6

摘要: Direct dehydrogenation with high selectivity and oxidative dehydrogenation with low thermal limit has been regarded as promising methods to solve the increasing demands of light olefins and styrene. Metal-based catalysts have shown remarkable performance for these reactions, such as Pt, CrOx, Co, ZrOx, Zn and V. Compared with metal-based catalysts, carbon materials with stable structure, rich pore texture and large surface area, are ideal platforms as the catalysts and the supports for dehydrogenation reactions. In this review, carbon materials applied in direct dehydrogenation and oxidative dehydrogenation reactions including ordered mesoporous carbon, carbon nanodiamond, carbon nanotubes, graphene and activated carbon, are summarized. A general introduction to the dehydrogenation mechanism and active sites of carbon catalysts is briefly presented to provide a deep understanding of the carbon-based materials used in dehydrogenation reactions. The unique structure of each carbon material is presented, and the diversified synthesis methods of carbon catalysts are clarified. The approaches for promoting the catalytic activity of carbon catalysts are elaborated with respect to preparation method optimization, suitable structure design and heteroatom doping. The regeneration mechanism of carbon-based catalysts is discussed for providing guidance on catalytic performance enhancement. In addition, carbon materials as the support of metal-based catalysts contribute to exploiting the excellent catalytic performance of catalysts due to superior structural characteristics. In the end, the challenges in current research and strategies for future improvements are proposed.

关键词: carbon materials     dehydrogenation     active sites     mechanism     catalytic performance     support    

Formic acid dehydrogenation reaction on high-performance PdAu alloy nanoparticles prepared by the eco-friendly

《能源前沿(英文)》   页码 751-762 doi: 10.1007/s11708-023-0895-3

摘要: Dehydrogenation of formic acid (FA) is considered to be an effective solution for efficient storage and transport of hydrogen. For decades, highly effective catalysts for this purpose have been widely investigated, but numerous challenges remain. Herein, the PdxAu1−x (x = 0, 0.2, 0.4, 0.5, 0.6, 0.8, 1) alloys over the whole composition range were successfully prepared and used to catalyze FA hydrogen production efficiently near room temperature. Small PdAu nanoparticles (5–10 nm) were well-dispersed and supported on the activated carbon to form PdAu solid solution alloys via the eco-friendly slow synthesis methodology. The physicochemical properties of the PdAu alloys were comprehensively studied by utilizing various measurement methods, such as X-ray diffraction (XRD), N2 adsorption–desorption, high angle annular dark field-scanning transmission electron microscope (HAADF-STEM), X-ray photoelectrons spectroscopy (XPS). Notably, owing to the strong metal-support interaction (SMSI) and electron transfer between active metal Au and Pd, the Pd0.5Au0.5 obtained exhibits a turnover frequency (TOF) value of up to 1648 h−1 (313 K, nPd+Au/nFA = 0.01, nHCOOH/nHCOONa = 1:3) with a high activity, selectivity, and reusability in the FA dehydrogenation.

关键词: FA dehydrogenation     face-centred cubic structures     PdAu solid solution alloy nanoparticles     slow synthesis methodology     SMSI effect    

Study on direct alcohol/ether fuel synthesis process in bubble column slurry reactor

Zhen CHEN, Haitao ZHANG, Weiyong YING, Dingye FANG

《化学科学与工程前沿(英文)》 2010年 第4卷 第4期   页码 461-471 doi: 10.1007/s11705-010-0517-6

摘要: The recent studies of direct alcohol/ether synthesis process in slurry reactors were reviewed, and the research work in our laboratory was carried out in this paper. a global kinetics model for direct dimethyl ether (DME) synthesis from syngas over a novel Cu-Zn-Al-Zr slurry catalyst was established according to the total of 25 experimental data, and a steady-state one-dimensional mathematical model was further developed in bubble column slurry reactor (BCSR), which was assumed that the bubble phase was plug flow, and the liquid phase was fully mixed flow. The numerical simulations of reactor design of 100000 t/a dimethyl ether pilot plant indicate that higher pressure and lower temperature were favorable to the increase of CO conversion, selectivity of dimethyl ether, product yield and height of slurry bed. The optimal operating conditions for DME synthesis process were obtained: reaction temperature at 240°C, reactor pressure at 5 MPa and reactor diameter of 2.5 m.

关键词: syngas     alcohol/ether fuel     slurry catalyst     bubble column slurry reactor     global kinetics     mathematical model    

Uncovering the effect of poly(ethylene-co-vinyl alcohol) molecular weight and vinyl alcohol content on

《化学科学与工程前沿(英文)》 2023年 第17卷 第10期   页码 1484-1502 doi: 10.1007/s11705-023-2331-y

摘要: Various hydrophilic poly(ethylene-co-vinyl alcohol) (EVOH) were used herein to precisely control the structure and hydrodynamic properties of polysulfone (PSF) membranes. Particularly, to prepare pristine PSF and PSF/EVOH blends with increasing vinyl alcohol (VOH: 73%, 68%, 56%), the non-solvent-induced phase separation (NIPS) technique was used. Polyethylene glycol was used as a compatibilizer and as a porogen in N,N-dimethylacetamide. Rheological and ultrasonic separation kinetic measurements were also carried out to develop an ultrafiltration membrane mechanism. The extracted membrane properties and filtration capabilities were systematically compared to the proposed mechanism. Accordingly, the addition of EVOH led to an increase in the rheology of the dopes. The resulting membranes exhibited a microporous structure, while the finger-like structures became more evident with increasing VOH content. The PSF/EVOH behavior was changed from immediate to delayed segregation due to a change in the hydrodynamic kinetics. Interestingly, the PSF/EVOH32 membranes showed high hydrophilicity and achieved a pure water permeability of 264 L·m–2·h–1·bar–1, which was higher than that of pure PSF membranes (171 L·m–2·h–1·bar–1). In addition, PSF/EVOH32 rejected bovine serum albumin at a high rate (> 90%) and achieved a significant restoration of permeability. Finally, from the thermodynamic and hydrodynamic results, valuable insights into the selection of hydrophilic copolymers were provided to tailor the membrane structure while improving both the permeability and antifouling performance.

关键词: polysulfone     blend modification     ultrafiltration membrane     formation hydrodynamics     poly(ethylene-co-vinyl alcohol) copolymer    

Hydrogenation of furfuryl alcohol to tetrahydrofurfuryl alcohol on NiB/SiO2 amorphous alloy catalyst

SONG Yun, LI Wei, ZHANG Minghui, TAO Keyi

《化学科学与工程前沿(英文)》 2007年 第1卷 第2期   页码 151-154 doi: 10.1007/s11705-007-0028-2

摘要: NiB/SiO amorphous alloy catalyst was prepared by power electroless plating method and characterized by induction coupled plasma (ICP), Brunauer Emmett Teller method (BET), transmission electron microscope (TEM) and X-ray diffraction (XRD) techniques. The catalytic performance of NiB/SiO was investigated for the hydrogenation of furfuryl alcohol (FA) to tetrahydrofurfuryl alcohol (THFA). The effects of operational conditions, such as reaction temperature, pressure, and stirring rate were carefully studied. The proper conditions were determined as the following: pressure 2.0 MPa, temperature 120?C and stirring rate 550 r/min. A typical result with FA conversion of 99% and THFA selectivity of 100% was obtained under such conditions, which was close to that over Raney Ni.

关键词: following     Brunauer     electroless     temperature     transmission    

Effect of decoction on CD14 expression in lipopolysaccharide signal transduction pathway of alcohol-induced

Rui ZHU MD , Lin SHEN MD , Jianguo LIU MD , Weili ZHANG MM , Ling YANG MD ,

《医学前沿(英文)》 2009年 第3卷 第3期   页码 363-367 doi: 10.1007/s11684-009-0064-z

摘要: This paper aims to investigate the effects of (枳黄) decoction on CD14 expression in the lipopolysaccharide signal transduction pathway of alcohol-induced liver disease in rats. Seventy-five Wistar rats were randomly divided into three groups. Ethanol (56%, weight/volumn) was intragastrically administrated to 50 rats (14mL/kg body weight per day) for 10 days to establish a model of alcohol-induced liver disease, and 25 of these 50 rats were treated with decoction simultaneously. Liver injury was evaluated by biochemical examination. The plasma content of endotoxin was assayed by biochemistry. The expression of CD14 mRNA and protein in rat liver was measured by reverse transcriptional polymerase chain reaction and immunohistochemistry, respectively. decoction pretreatment significantly protected against acute alcohol-induced liver injury, which was evidenced by the decrease of elevated serum alanine aminotransferase and aspartate aminotransferase. In addition, the level of plasma endotoxin and up-regulation of CD14 was also suppressed by decoction in alcohol-intoxicated rats. decoction can significantly reduce CD14 expression in the lipopolysaccharide signal transduction pathway, which is one of the most important mechanisms of decoction to treat hepatic injury induced by alcohol in rats.

关键词: liver disease     alcohol     Zhihuang decoction     CD14     signal transduction    

Molecular diffusion in ternary poly(vinyl alcohol) solutions

《化学科学与工程前沿(英文)》 2022年 第16卷 第6期   页码 1003-1016 doi: 10.1007/s11705-021-2121-3

摘要: The diffusion kinetics of a molecular probe—rhodamine B—in ternary aqueous solutions containing poly(vinyl alcohol), glycerol, and surfactants was investigated using fluorescence correlation spectroscopy and dynamic light scattering. We show that the diffusion characteristics of rhodamine B in such complex systems is determined by a synergistic effect of molecular crowding and intermolecular interactions between chemical species. The presence of glycerol has no noticeable impact on rhodamine B diffusion at low concentration, but significantly slows down the diffusion of rhodamine B above 3.9% (w/v) due to a dominating steric inhibition effect. Furthermore, introducing surfactants (cationic/nonionic/anionic) to the system results in a decreased diffusion coefficient of the molecular probe. In solutions containing nonionic surfactant, this can be explained by an increased crowding effect. For ternary poly(vinyl alcohol) solutions containing cationic or anionic surfactant, surfactant–polymer and surfactant–rhodamine B interactions alongside the crowding effect of the molecules slow down the overall diffusivity of rhodamine B. The results advance our insight of molecular migration in a broad range of industrial complex formulations that incorporate multiple compounds, and highlight the importance of selecting the appropriate additives and surfactants in formulated products.

关键词: fluorescence correlation spectroscopy     poly(vinyl alcohol)     anomalous diffusion     crowding effects     dynamic light scattering     binding effects     rhodamine B    

Using crosslinked polyvinyl alcohol polymer membrane as a separator in the microbial fuel cell

Yanping HOU, Kaiming LI, Haiping LUO, Guangli LIU, Renduo ZHANG, Bangyu QIN, Shanshan CHEN

《环境科学与工程前沿(英文)》 2014年 第8卷 第1期   页码 137-143 doi: 10.1007/s11783-013-0534-z

摘要: Separator between anode and cathode is an essential part of the microbial fuel cell (MFC) and its property could significantly influence the system performance. In this study we used polyvinyl alcohol (PVA) polymer membrane crosslinked with sulfosuccinic acid (SSA) as a new separator for the MFC. The highest power density of 759±4 mW·m was obtained when MFC using the PVA membrane crosslinked with 15% of SSA due to its desirable proton conductivity (5.16 × 10 S·cm ). The power density significantly increased to 1106±30?mW·m with a separator-electrode-assembly configuration, which was comparable with glass fiber (1170±46?mW·m ). The coulombic efficiencies of the MFCs with crosslinked PVA membranes ranged from 36.3% to 45.7% at a fix external resistance of 1000 ?. The crosslinked PVA membrane could be a promising alternative to separator materials for constructing practical MFC system.

关键词: microbial fuel cell     crosslinked polyvinyl alcohol (PVA) membrane     separator material     power generation     coulombic efficiency    

Degradation of bisphenol A by microorganisms immobilized on polyvinyl alcohol microspheres

Xue BAI, Hanchang SHI, Zhengfang YE, Qiujin SUN, Qing WANG, Zhongyou WANG

《环境科学与工程前沿(英文)》 2013年 第7卷 第6期   页码 844-850 doi: 10.1007/s11783-013-0487-2

摘要: In this study, microorganisms (named B111) were immobilized on polyvinyl alcohol microspheres prepared by the inverse suspension crosslinked method. The biodegradation of bisphenol A (BPA) and 4-hydroxybenzaldehyde, a degradation product of BPA, by free and immobilized B111 was investigated. The BPA degradation studies were carried out at initial BPA concentrations ranging from 25 to 150 mg·L . The affinity constant K and maximum degradation rate were 98.3 mg·L and 19.7 mg·mg VSS·d for free B111, as well as 87.2 mg·L and 21.1 mg·mg VSS·d for immobilized B111, respectively. 16S rDNA gene sequence analyses confirmed that the dominant genera were and for BPA biodegradation in microorganisms B111.

关键词: bisphenol A     polyvinyl alcohol     immobilized microorganisms     4-hydroxybenzaldehyde    

stabilization effect of Al2O3 on unconventional Pb/SiO2 catalyst for propane dehydrogenation

《化学科学与工程前沿(英文)》 2023年 第17卷 第10期   页码 1423-1429 doi: 10.1007/s11705-023-2315-y

摘要: Similar to Sn, Pb located at the same group (IVA) in the periodic table of elements, can also catalyze propane dehydrogenation to propene, while a fast deactivation can be observed. To enhance the stability, the traditional carrier Al2O3 with a small amount, was introduced into Pb/SiO2 catalyst in this study. It has been proved that Al2O3 can inhibit the reduction of PbO, and weaken the agglomeration and loss of Pb species due to its enhanced interaction with Pb species. As a result, 3Al15Pb/SiO2 catalyst exhibits a much higher stability up to more than 150 h. In addition, a simple schematic diagram of the change of surface species on the catalyst surface after Al2O3 addition was also proposed.

关键词: Pb/SiO2     Al2O3     propane dehydrogenation     propene     stability    

Recovery of free volume in PIM-1 membranes through alcohol vapor treatment

Faiz Almansour, Monica Alberto, Rupesh S. Bhavsar, Xiaolei Fan, Peter M. Budd, Patricia Gorgojo

《化学科学与工程前沿(英文)》 2021年 第15卷 第4期   页码 872-881 doi: 10.1007/s11705-020-2001-2

摘要: Physical aging is currently a major obstacle for the commercialization of PIM-1 membranes for gas separation applications. A well-known approach to reversing physical aging effects of PIM-1 membranes at laboratory scale is soaking them in lower alcohols, such as methanol and ethanol. However, this procedure does not seem applicable at industrial level, and other strategies must be investigated. In this work, a regeneration method with alcohol vapors (ethanol or methanol) was developed to recover permeability of aged PIM-1 membranes, in comparison with the conventional soaking-in-liquid approach. The gas permeability and separation performance, before and post the regeneration methods, were assessed using a binary mixture of CO and CH (1:1, v:v). Our results show that an 8-hour methanol vapor treatment was sufficient to recover the original gas permeability, reaching a CO permeability>7000 barrer.

关键词: polymer of intrinsic microporosity (PIM)     PIM-1     physical aging     gas separation     vapor-phase regeneration    

Characterization of Bacillus amyloliquefacien contaminating 75% alcohol disinfectant

ZHANG Wanming, YUAN Yuesha, BIAN Cangli, TU Xianyu, ZHANG Wen, HUANG Huqiang, WANG Lan

《医学前沿(英文)》 2008年 第2卷 第1期   页码 113-116 doi: 10.1007/s11684-008-0021-2

摘要: The clinical characterization of Bacillus amyloliquefacien contaminating 75% alcohol disinfectants were studied. The bacteria were cultured and observed by using bacterial examination under the hospital infection monitor. According to the regulations, the resistance of bacterial to physical and chemical factors was tested. Drug sensitivity tests for 20 commonly used medicines were carried out using a K-B method. The bacterial plasmids were analyzed using the Birnboim method. The bacteria were found after being cultured in the clinically-used 75% alcohol disinfectant fluid. Their total number was more than 800 cfu/mL and they were identified as Bacillus amyloliquefacien. The bacteria were also found to be resistant to boiling for 5 min. It grew well in 95% alcohol disinfectant and was insensitive to 84 disinfectant fluids containing chlorine (1000 mg/L) and such disinfectants as ozone. They were able to be sterilized better through routine ultraviolet exposure for 30 min or gas pressure. The bacteria contained a 2.5 kb plasmid and were sensitive to 13 drugs and insensitive to 7 drugs of the 20 drugs tested. It was suggested that alcohol disinfectant fluid was easily contaminated by Bacillus amyloliquefacien, and the bacteria was resistant to disinfectant fluids such as alcohol and 84 disinfectants

Separation of 1,3-propanediol from glycerol-based fermentations of Klebsiella pneumoniae by alcohol precipitation

GAO Sujun, SUN Yaqin, XIU Zhilong

《化学科学与工程前沿(英文)》 2007年 第1卷 第2期   页码 202-207 doi: 10.1007/s11705-007-0037-1

摘要: The separation of 1,3-propanediol from the glycerol-based fermentation broth of plays an important role during the microbial production of 1,3-propanediol. In this paper, the separation of 1,3-propanediol from fermentative broth by a combination of ultrafiltration and alcohol dilution crystallization was investigated. The broth was first filtered by ultrafiltration, and 99% of cells, 89.4% of proteins and 69% of nucleic acids were removed. The obtained broth was further condensed by vac uum distillation, and then alcohol was added. The macromolecular impurities, such as nucleic acids, polysaccharides and proteins, were precipitated, and inorganic and organic salts were crystallized. The optimal volume ratio of alcohol added to the condensed fermentation broth was determined to be 2:1. As a result, proteins, nucleic acids and electric conductivity decreased by 97.4%, 89.7% and 95.8%, respectively, compared with the fermentative broth. The influences of pH and water content in condensed broth on alcohol precipitation and dilution crystallization were also investigated. The experimen tal results indicated that alcohol precipitation and dilution crystallization was feasible and effective for the separation of 1,3-propanediol from actual fermentation broth.

Ionic liquid mediated esterification of alcohol with acetic acid

Beilei ZHOU, Yanxiong FANG, Hao GU, Saidan ZHANG, Baohua HUANG, Kun ZHANG

《化学科学与工程前沿(英文)》 2009年 第3卷 第2期   页码 211-214 doi: 10.1007/s11705-009-0054-3

摘要: Highly efficient esterification of alcohols with acetic acid by using a Br?nsted acidic ionic liquid, i.e., 1-methyl-2-pyrrolidonium hydrogen sulfate ([Hnmp]HSO ), as catalyst has been realized. The turnover numbers (TON) were able to reach up to 11000 and turnover frequency (TOF) was 846. The catalytic system is suitable for the esterification of long chain aliphatic alcohols, benzyl alcohol and cyclohexanol with good yields of esters. The procedure of separating the product and catalyst is simple, and the catalyst could be reused. [Hnmp]HSO had much weaker corrosiveness than H SO . The corrosive rate of H SO was 400 times more than that of [Hnmp]HSO to stainless steel.

关键词: ionic liquid     Br?nsted acid     esterification     catalyst    

标题 作者 时间 类型 操作

Effects of ancillary ligands in acceptorless benzyl alcohol dehydrogenation mediated by phosphine-free

期刊论文

Insights into carbon-based materials for catalytic dehydrogenation of low-carbon alkanes and ethylbenzene

期刊论文

Formic acid dehydrogenation reaction on high-performance PdAu alloy nanoparticles prepared by the eco-friendly

期刊论文

Study on direct alcohol/ether fuel synthesis process in bubble column slurry reactor

Zhen CHEN, Haitao ZHANG, Weiyong YING, Dingye FANG

期刊论文

Uncovering the effect of poly(ethylene-co-vinyl alcohol) molecular weight and vinyl alcohol content on

期刊论文

Hydrogenation of furfuryl alcohol to tetrahydrofurfuryl alcohol on NiB/SiO2 amorphous alloy catalyst

SONG Yun, LI Wei, ZHANG Minghui, TAO Keyi

期刊论文

Effect of decoction on CD14 expression in lipopolysaccharide signal transduction pathway of alcohol-induced

Rui ZHU MD , Lin SHEN MD , Jianguo LIU MD , Weili ZHANG MM , Ling YANG MD ,

期刊论文

Molecular diffusion in ternary poly(vinyl alcohol) solutions

期刊论文

Using crosslinked polyvinyl alcohol polymer membrane as a separator in the microbial fuel cell

Yanping HOU, Kaiming LI, Haiping LUO, Guangli LIU, Renduo ZHANG, Bangyu QIN, Shanshan CHEN

期刊论文

Degradation of bisphenol A by microorganisms immobilized on polyvinyl alcohol microspheres

Xue BAI, Hanchang SHI, Zhengfang YE, Qiujin SUN, Qing WANG, Zhongyou WANG

期刊论文

stabilization effect of Al2O3 on unconventional Pb/SiO2 catalyst for propane dehydrogenation

期刊论文

Recovery of free volume in PIM-1 membranes through alcohol vapor treatment

Faiz Almansour, Monica Alberto, Rupesh S. Bhavsar, Xiaolei Fan, Peter M. Budd, Patricia Gorgojo

期刊论文

Characterization of Bacillus amyloliquefacien contaminating 75% alcohol disinfectant

ZHANG Wanming, YUAN Yuesha, BIAN Cangli, TU Xianyu, ZHANG Wen, HUANG Huqiang, WANG Lan

期刊论文

Separation of 1,3-propanediol from glycerol-based fermentations of Klebsiella pneumoniae by alcohol precipitation

GAO Sujun, SUN Yaqin, XIU Zhilong

期刊论文

Ionic liquid mediated esterification of alcohol with acetic acid

Beilei ZHOU, Yanxiong FANG, Hao GU, Saidan ZHANG, Baohua HUANG, Kun ZHANG

期刊论文