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Controllable synthesis of a large TS-1 catalyst for clean epoxidation of a C=C double bond under mild

《化学科学与工程前沿（英文）》 2023年 第17卷 第6期   页码 772-783 doi: 10.1007/s11705-022-2280-x

摘要： Development of a titanium silicalite-1 (TS-1) catalyst with good crystallinity and a four-coordinate Ti framework is critical for efficient catalytic oxidation reaction under mild conditions. Herein, a size-controlled TS-1 zeolite (TS-1#0.1ACh (acetylcholine)) was synthesized via steam-assisted crystallization by introducing acetylcholine as a crystal growth modifier in the preparation process, and TS-1#0.1ACh was also employed in epoxidations of different substrates containing C=C double bonds. The crystalline sizes of the as-synthesized TS-1#0.1ACh catalysts were controlled with the acetylcholine content, and characterization results showed that the particle sizes of highly crystalline TS-1#0.1ACh zeolite reached 3.0 μm with a good Ti framework. Throughout the synthetic process, the growth rate of the crystals was accelerated by electrostatic interactions between the connected hydroxyl groups of the acetylcholine modifier and the negatively charged skeleton of the pre-zeolites. Furthermore, the TS-1#0.1ACh catalyst demonstrated maximum catalytic activity, good selectivity and high stability during epoxidation of allyl chloride. Importantly, the TS-1#0.1ACh catalyst was also highly versatile and effective with different unsaturated substrates. These findings may provide novel, easily separable and large TS-1 catalysts for efficient and clean industrial epoxidations of C=C double bonds.

关键词： size-controlled TS-1     crystal modifier     steam-assisted crystallization     epoxidation    

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Development of an H reduction and moderate oxidation method for 3,5-dimethylpyridine hydrogenation in trickle bed reactor

《化学科学与工程前沿（英文）》 2022年 第16卷 第12期   页码 1807-1817 doi: 10.1007/s11705-022-2243-2

摘要： The Ru/C catalyst prepared by impregnation method was used for hydrogenation of 3,5-dimethylpyridine in a trickle bed reactor. Under the same reduction conditions (300 °C in H2), the catalytic activity of the non-in-situ reduced Ru/C-n catalyst was higher than that of the in-situ reduced Ru/C-y catalyst. Therefore, an in-situ H2 reduction and moderate oxidation method was developed to increase the catalyst activity. Moreover, the influence of oxidation temperature on the developed method was investigated. The catalysts were characterized by Brunauer–Emmett–Teller method, hydrogen temperature programmed reduction H2-TPR, hydrogen temperature-programmed dispersion (H2-TPD), X-ray diffraction, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, O2 chemisorption and oxygen temperature-programmed dispersion (O2-TPD) analyses. The results showed that there existed an optimal Ru/RuOx ratio for the catalyst, and the highest 3,5-dimethylpyridine conversion was obtained for the Ru/C-i1 catalyst prepared by in-situ H2 reduction and moderate oxidation (oxidized at 100 °C). Excessive oxidation (200 °C) resulted in a significant decrease in the Ru/RuOx ratio of the in-situ H2 reduction and moderate oxidized Ru/C-i2 catalyst, the interaction between RuOx species and the support changed, and the hard-to-reduce RuOx species was formed, leading to a significant decrease in catalyst activity. The developed in-situ H2 reduction and moderate oxidation method eliminated the step of the non-in-situ reduction of catalyst outside the trickle bed reactor.

关键词： Ru/C catalyst     in-situ H2 reduction and moderate oxidation     in-situ reduction     non-in-situ reduction     hydrogenation of 3     5-dimethylpyridine    

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Monte Carlo simulation of the PEMFC catalyst layer

WANG Hongxing, CAO Pengzhen, WANG Yuxin

《化学科学与工程前沿（英文）》 2007年 第1卷 第2期   页码 146-150 doi: 10.1007/s11705-007-0027-3

摘要： The performance of the polymer electrolyte membrane fuel cell (PEMFC) is greatly controlled by the structure of the catalyst layer. Low catalyst utilization is still a significant obstacle to the commercialization of the PEMFC. In order to get a fundamental understanding of the electrode structure and to find the limiting factor in the low catalyst utilization, it is necessary to develop the mechanical model on the effect of catalyst layer structure on the catalyst utilization and the performance of the PEMFC. In this work, the structure of the catalyst layer is studied based on the lattice model with the Monte Carlo simulation. The model can predict the effects of some catalyst layer components, such as Pt/C catalyst, electrolyte and gas pores, on the utilization of the catalyst and the cell performance. The simulation result shows that the aggregation of conduction grains can greatly affect the degree of catalyst utilization. The better the dispersion of the conduction grains, the larger the total effective area of the catalyst is. To achieve higher utilization, catalyst layer components must be distributed by means of engineered design, which can prevent aggregation.

关键词： catalyst utilization     PEMFC     commercialization     Pt/C catalyst     conduction    

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Atomistic simulations of plasma catalytic processes

Erik C. Neyts

《化学科学与工程前沿（英文）》 2018年 第12卷 第1期   页码 145-154 doi: 10.1007/s11705-017-1674-7

摘要： There is currently a growing interest in the realisation and optimization of hybrid plasma/catalyst systems for a multitude of applications, ranging from nanotechnology to environmental chemistry. In spite of this interest, there is, however, a lack in fundamental understanding of the underlying processes in such systems. While a lot of experimental research is already being carried out to gain this understanding, only recently the first simulations have appeared in the literature. In this contribution, an overview is presented on atomic scale simulations of plasma catalytic processes as carried out in our group. In particular, this contribution focusses on plasma-assisted catalyzed carbon nanostructure growth, and plasma catalysis for greenhouse gas conversion. Attention is paid to what can routinely be done, and where challenges persist.

关键词： atomic scale simulation     plasma-catalyst    

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New insight into effect of potential on degradation of Fe-N-C catalyst for ORR

Yanyan GAO, Manman QI, Liang HE, Haiping CHEN, Wenzhe LUO, Ming HOU, Zhigang SHAO

《能源前沿（英文）》 2021年 第15卷 第2期   页码 421-430 doi: 10.1007/s11708-021-0727-2

摘要： In recent years, Fe-N-C catalyst is particularly attractive due to its high oxygen reduction reaction (ORR) activity and low cost for proton exchange membrane fuel cells (PEMFCs). However, the durability problems still pose challenge to the application of Fe-N-C catalyst. Although considerable work has been done to investigate the degradation mechanisms of Fe-N-C catalyst, most of them are simply focused on the active-site decay, the carbon oxidation, and the demetalation problems. In fact, the 2e pathway in the ORR process of Fe-N-C catalyst would result in the formation of H O , which is proved to be a key degradation source. In this paper, a new insight into the effect of potential on degradation of Fe-N-C catalyst was provided by quantifying the H O intermediate. In this case, stability tests were conducted by the potential-static method in O saturated 0.1 mol/L HClO . During the tests, H O was quantified by rotating ring disk electrode (RRDE). The results show that compared with the loading voltage of 0.4 V, 0.8 V, and 1.0 V, the catalysts being kept at 0.6 V exhibit a highest H O yield. It is found that it is the combined effect of electrochemical oxidation and chemical oxidation (by aggressive radicals like H O /radicals) that triggered the highest H O release rate, with the latter as the major cause.

关键词： proton exchange membrane fuel cells (PEMFCs)     oxygen reduction reaction (ORR)     Fe-N-C catalyst     potential     H2O2     degradation    

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hydrogenation of insoluble organic matter of CS/Acetone from coal over mesoporous HZSM-5 supported Ni and Ru

《化学科学与工程前沿（英文）》 2022年 第16卷 第10期   页码 1505-1513 doi: 10.1007/s11705-022-2164-0

摘要： Four supported catalysts, nickel and ruthenium on a HZSM-5 support, were prepared by equal volume impregnation and in-situ decomposition of carbonyl nickel. The properties of catalysts were investigated by catalytic hydro-conversion of 2,2′-dinaphthyl ether as the model compound and extraction residue of Naomaohu lignite as the sample under an initial H2 pressure of 5 MPa and temperature at 150 °C. According to the catalytic hydro-conversion results of the model compound, Ni−Ru/HZSM-5 exhibited the best catalytic performance. It not only activated H2 into H···H, but also further heterolytically split H···H into immobile H‒ attached on the acidic centers of Ni−Ru/HZSM-5 and relatively mobile H+. Catalytic hydro-conversion of the extraction residue from Naomaohu lignite was further examined over the optimized catalyst, Ni−Ru/HZSM-5. Detailed molecular compositions of products from the extraction residue with and without hydrogenation were characterized by Fourier transform infrared spectroscopy and gas chromatography/mass spectrometry. The analytical results showed that the oxygen-containing functional groups in products of hydrogenated extraction residue were obviously reduced after the catalytic treatment. The relative content of oxygenates in the product with catalytic treatment was 18.57% lower than that in the product without catalytic treatment.

关键词： HZSM-5     Ni-based catalyst     catalytic hydrogenation     coal     model compound    

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Kinetic model for hydroisomerization reaction of C-aromatics

XU Ouguan, SU Hongye, JIN Xiaoming, CHU Jian

《化学科学与工程前沿（英文）》 2008年 第2卷 第1期   页码 10-16 doi: 10.1007/s11705-008-0015-2

摘要： Based on the reported reaction networks, a novel six-component hydroisomerization reaction network with a new lumped species including C-naphthenes and C-paraffins is proposed and a kinetic model for a commercial unit is also developed. An empirical catalyst deactivation function is incorporated into the model accounting for the loss in activity because of coke formation on the catalyst surface during the long-term operation. The Runge-Kutta method is used to solve the ordinary differential equations of the model. The reaction kinetic parameters are benchmarked with several sets of balanced plant data and estimated by the differential variable metric optimization method (BFGS). The kinetic model is validated by an industrial unit with sets of plant data under different operating conditions and simulation results show a good agreement between the model predictions and the plant observations.

关键词： ordinary differential     Runge-Kutta     catalyst deactivation     C-paraffins     optimization    

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Biopolymer-stabilized emulsions on the basis of interactions between β -lactoglobulin and ι -carrageenan

Qiaomei RU, Younghee CHO, Qingrong HUANG,

《化学科学与工程前沿（英文）》 2009年 第3卷 第4期   页码 399-406 doi: 10.1007/s11705-009-0253-y

摘要： -Carrageenan and -lactoglobulin (-lg) stabilized oil-in-water (O/W) emulsions, which can be used for the oral administration of bioactive but environmentally sensitive ingredients, have been successfully prepared. The effects of protein/polysaccharide ratios, total biopolymer concentration, environmental stress (thermal processing and sonication), and pH on the complex formation between -carrageenan and -lactoglobulin have been investigated. We found that -lactoglobulin and-carrageenan stabilized emulsions can be formed at pH values of 6.0, 4.0, and 3.4. However, the microstructures of emulsions stabilized by -lactoglobulin and -carrageenan was identified by optical microscopy, and it indicated that the emulsion prepared at pH 6.0 flocculated more extensively, while its hydrodynamic radius was much bigger than those prepared at pH 4.0 and 3.4. Regarding rheological properties, the emulsion of pH 6.0 showed a more solid-like behavior but with a lower viscosity than those of pH 4.0 and 3.4. The optimum concentration ranges for -lg and-carrageenan to form stable emulsions at pH 4.0 and 3.4 were 0.3wt-%―0.6wt-% and 0.4wt-%―0.7wt-%, respectively.
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C8芳烃异构化催化剂的开发及应用

乔映宾

《中国工程科学》 1999年 第1卷 第1期   页码 73-77

摘要：

文章介绍了SKI系列C8芳烃异构化催化剂研究工作的进展。阐述了催化剂研制开发的创新思路以及该催化剂的优异性能。该催化剂可使贫对二甲苯或贫对、邻二甲苯的混合C8芳烃异构为接近热力学平衡的C8芳烃，C8芳烃的选择性大于97%，使用寿命可达5年以上。并介绍了该催化剂在引进的七套C8芳烃异构化工业装置上取代了进口催化剂，将该科技成果转化为现实的生产力所取得的成绩。

关键词： 异构化     催化剂     二甲苯    

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Probing the catalytic activity of M-N

Fan Ge, Qingan Qiao, Xin Chen, You Wu

《化学科学与工程前沿（英文）》 2021年 第15卷 第5期   页码 1206-1216 doi: 10.1007/s11705-020-2017-7

摘要： In this work, the detailed oxygen reduction reaction (ORR) catalytic performance of M-N O (M= Fe, Co, and Ni; = 1–4) has been explored via the detailed density functional theory method. The results suggest that the formation energy of M-N O shows a good linear relationship with the number of doped O atoms. The adsorption manner of O on M-N O changed from end-on ( = 1 and 2) to side-on ( = 3 and 4), and the adsorption strength gradually increased. Based on the results for binding strength of ORR intermediates and the Gibbs free energy of ORR steps on the studied catalysts, we screened out two highly active ORR catalysts, namely Co-N O and Ni-N O , which possess very small overpotentials of 0.27 and 0.32 V, respectively. Such activities are higher than the precious Pt catalyst. Electronic structure analysis reveals one of the reasons for the higher activity of Co-N O and Ni-N O is that they have small energy gaps and moderate highest occupied molecular orbital energy levels. Furthermore, the results of the density of states reveal that the O doping can improve the electronic structure of the original catalyst to tune the adsorption of the ORR intermediates.

关键词： M-N-C catalyst     oxygen doping     oxygen reduction reaction     catalytic activity     density functional theory    

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Genetics of ischemic and hemorrhagic stroke in Chinese population

Wei-Li ZHANG MD, PhD, Ru-Tai HUI MD, PhD,

《医学前沿（英文）》 2010年 第4卷 第1期   页码 21-28 doi: 10.1007/s11684-010-0013-x

摘要： Stroke is a major cause of adult death and disability worldwide. Epidemiological and animal studies have provided strong evidence that the pathogenesis of stroke is multi-factorial and induced by a combination of environmental and genetic risk factors, but the identification of individual causative variants remains little known. Genetic influences are likely to be polygenic with small effect sizes, and stroke itself consists of a number of different subtypes which may each have different genetic profiles. In addition, various ethnic populations may have different stroke risk, such as Asian race. The reasons for high risk of stroke among the Chinese, especially hemorrhagic stroke, remain unknown. Most human studies have taken a candidate gene approach using case-control methodology. To be reliably detected, small relative risks require large sample sizes, probably 1000 patients or more. Genome-wide association (GWA) study is an unbiased and comprehensive approach to identify common risk alleles for complex diseases. Recently, a multistage GWA study has identified three loci on chromosomes 2q, 8q and 9p to be associated with intracranial aneurysm in European and Japanese populations. Another GWA finding is the identification of risk variants for cardioembolic stroke on chromosome 4q25 in European populations. In this review, we mainly focus on the results from case-control association studies on genetic factors that play a role in the risk of ischemic and hemorrhagic stroke in Chinese population. The combined effects of multiple susceptibility genes for stroke risk are also summarized.

关键词： genetics     ischemic stroke     hemorrhagic stroke     association study    

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Catalytic activity of cerium-doped Ru/AlO during ozonation of dimethyl phthalate

ZHOU Yunrui, ZHU Wanpeng, CHEN Xun

《环境科学与工程前沿（英文）》 2008年 第2卷 第3期   页码 354-357 doi: 10.1007/s11783-008-0059-z

摘要： In this paper, factors influencing the mineralization of dimethyl phthalate (DMP) during catalytic ozonation with a cerium-doped Ru/AlO catalyst were studied. The catalytic contribution was calculated through the results of a comparison experiment. It showed that doping cerium significantly enhanced catalytic activity. The total organic carbon (TOC) removal over the doped catalyst at 100 min reached 75.1%, 61.3% using Ru/AlO catalyst and only 14.0% using ozone alone. Catalytic activity reached the maximum when 0.2% of ruthenium and 1.0% of cerium were simultaneously loaded onto AlO support. Results of experiments on oxidation by ozone alone, adsorption of the catalyst, Ce ion’s and heterogeneous catalytic ozonation confirmed that the contribution of heterogeneous catalytic ozonation was about 50%, which showed the obvious effect of Ru–Ce/AlO on catalytic activity.

关键词： Ru–Ce/AlO     dimethyl phthalate     mineralization     comparison experiment     catalytic ozonation    

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Chemical poison and regeneration of SCR catalysts for NOx removal from stationary sources

Junhua LI,Yue PENG,Huazhen CHANG,Xiang LI,John C. CRITTENDEN,Jiming HAO

《环境科学与工程前沿（英文）》 2016年 第10卷 第3期   页码 413-427 doi: 10.1007/s11783-016-0832-3

摘要： Selective catalytic reduction (SCR) of NO with NH is an effective technique to remove NO from stationary sources, such as coal-fired power plant and industrial boilers. Some of elements in the fly ash deactivate the catalyst due to strong chemisorptions on the active sites. The poisons may act by simply blocking active sites or alter the adsorption behaviors of reactants and products by an electronic interaction. This review is mainly focused on the chemical poisoning on V O -based catalysts, environmental-benign catalysts and low temperature catalysts. Several common poisons including alkali/alkaline earth metals, SO and heavy metals etc. are referred and their poisoning mechanisms on catalysts are discussed. The regeneration methods of poisoned catalysts and the development of poison-resistance catalysts are also compared and analyzed. Finally, future research directions in developing poisoning resistance catalysts and facile efficient regeneration methods for SCR catalysts are proposed.

关键词： flue gas     DeNOx     SCR catalyst     poison and regeneration    

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Research on port ecological suitability evaluation index system and evaluation model

Yaofeng XIE,Xia LV,Ru LIU,Liuyan MAO,Xiaoxi LIU

《结构与土木工程前沿（英文）》 2015年 第9卷 第1期   页码 65-70 doi: 10.1007/s11709-014-0258-6

摘要： Along with the rapid development of port building, the negative impacts of port’s construction and operation on the coastline ecosystem are also increasingly strong. Therefore, it’s urgent to establish a scientific and complete system of port ecological suitability evaluation. This paper pointed out the characteristics of port ecological effects and the principles of selecting evaluation index, and used the “pressure-state-response (PSR)” model to analysis the various pressures on the environment caused by port construction and operation, and the system’s response. On this basis, we constructed the port ecological suitability evaluation index. This model used the combination of qualitative and quantitative analytic hierarchy process, to meet the multi-level, multi-objective characteristics of evaluation index system. The evaluation index system and evaluation model can be used to analysis the ecological suitability of port projects comprehensively and have some guiding significance to the port ecological suitability evaluation.

关键词： port     ecological suitability     press-state-response (PSR) model     evaluation index system    

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A facile synthesis of high activity cube-like Pt/carbon composites for fuel cell application

Reza B. MOGHADDAM, Samaneh SHAHGALDI, Xianguo LI

《能源前沿（英文）》 2017年 第11卷 第3期   页码 245-253 doi: 10.1007/s11708-017-0492-4

摘要： High activity catalyst with simple low-cost synthesis is essential for fuel cell commercialization. In this study, a facile procedure for the synthesis of cube-like Pt nanoparticle (Pt ) composites with high surface area carbon supports is developed by mixing precursor of Pt with carbon supports in organic batches, hence, one pot synthesis. The Pt grow with Vulcan XC-72 or Ketjen black, respectively, and then treated for 5.5 h at 185ºC (i.e., Pt /V and Pt /K). The resulting particle sizes and shapes are similar; however, Pt /K has a larger electrochemical active surface area (EASA) and a remarkably better formic acid (FA) oxidation performance. Optimization of the Pt /K composites leads to Pt /K that has been treated for 10 h at 185ºC. With a larger EASA, Pt /K is also more active in FA oxidation than the other Pt /K composites. Impedance spectroscopy analysis of the temperature treated and as-prepared (i.e., untreated) Pt /K composites indicates that Pt /K is less resistive, and has the highest limiting capacitance among the Pt /K electrodes. Consistently, the voltammetric EASA is the largest for Pt /K. Furthermore, Pt /K is compared with two commercial Pt/C catalysts, Tanaka Kikinzoku Kogyo (TKK), and Johnson Matthey (JM)Pt/C catalysts. The TKK Pt/C has a higher EASA than Pt /K, as expected from their relative particles sizes (3–4 nm vs. 6–7 nm for Pt /K), however, Pt /K has a significantly better FA oxidation activity.

关键词： synthesis     cube-like Pt     Pt/C composite     catalyst     impedance    

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标题 作者 时间 类型 操作

Controllable synthesis of a large TS-1 catalyst for clean epoxidation of a C=C double bond under mild

期刊论文

Development of an H reduction and moderate oxidation method for 3,5-dimethylpyridine hydrogenation in trickle bed reactor

期刊论文

Monte Carlo simulation of the PEMFC catalyst layer

WANG Hongxing, CAO Pengzhen, WANG Yuxin

期刊论文

Atomistic simulations of plasma catalytic processes

Erik C. Neyts

期刊论文

New insight into effect of potential on degradation of Fe-N-C catalyst for ORR

Yanyan GAO, Manman QI, Liang HE, Haiping CHEN, Wenzhe LUO, Ming HOU, Zhigang SHAO

期刊论文

hydrogenation of insoluble organic matter of CS/Acetone from coal over mesoporous HZSM-5 supported Ni and Ru

期刊论文

Kinetic model for hydroisomerization reaction of C-aromatics

XU Ouguan, SU Hongye, JIN Xiaoming, CHU Jian

期刊论文

Biopolymer-stabilized emulsions on the basis of interactions between β -lactoglobulin and ι -carrageenan

Qiaomei RU, Younghee CHO, Qingrong HUANG,

期刊论文

C8芳烃异构化催化剂的开发及应用

乔映宾

期刊论文

Probing the catalytic activity of M-N

Fan Ge, Qingan Qiao, Xin Chen, You Wu

期刊论文

Genetics of ischemic and hemorrhagic stroke in Chinese population

Wei-Li ZHANG MD, PhD, Ru-Tai HUI MD, PhD,

期刊论文

Catalytic activity of cerium-doped Ru/AlO during ozonation of dimethyl phthalate

ZHOU Yunrui, ZHU Wanpeng, CHEN Xun

期刊论文

Chemical poison and regeneration of SCR catalysts for NOx removal from stationary sources

Junhua LI,Yue PENG,Huazhen CHANG,Xiang LI,John C. CRITTENDEN,Jiming HAO

期刊论文

Research on port ecological suitability evaluation index system and evaluation model

Yaofeng XIE,Xia LV,Ru LIU,Liuyan MAO,Xiaoxi LIU

期刊论文

A facile synthesis of high activity cube-like Pt/carbon composites for fuel cell application

Reza B. MOGHADDAM, Samaneh SHAHGALDI, Xianguo LI

期刊论文