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Ti incorporation in MCM-41 mesoporous molecular sieves using hydrothermal synthesis

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Frontiers of chemical Science and engineering 2014年第1期8卷 95-103页

作者： Shengping WANG Changqing MA Yun SHI Xinbin MA Key Laboratory for Green chemical Technology of Ministry of Education School of Chemical Engineering and Technology Tianjin University Collaborative Innovation Center of chemical Science and engineering Tianjin 300072 China Patent Examination Cooperation Center of the Patent Office SIPO Beijing 100088 China

Abstract Titanium-containing mesoporous materials （Ti-MCM-41） were obtained by hydrothennal synthesis. Such materials are active catalysts for the transesterifica- tion of dimethyl oxalate and phenol to produce diphenyl oxalate. To understand the role of the Ti in the catalytic process, Ti-MCM-41 samples with different Si/Ti ratios （from 5 to 100） were prepared and the samples were analyzed by Fourier transform infrared spectroscopy, UV- visible spectroscopy, and ammonia temperature pro- grammed desorption. It was concluded that the Ti is incorporated into the framework of the MCM-41 and formed weak Lewis acid sites. In addition, the number of Ti（IV） sites increased as the amount of titanium increased. X-ray powder diffraction, N2 adsorpfion-desorption and transmission electron microscopy results showed that the Ti-MCM-41 samples have a hexagonal arrangement of mono-dimensional pores. A large number of Ti（IV） sites coupled with the mesoporous structure and large pore diameters are favorable for the transesterification catalytic properties of Ti-MCM-41.

关键词： Ti-MCM-41 mesoporous molecular sieve,acid sites transesterification hydrothermal synthesis

A Cu-Pd alloy catalyst with partial phase separation for the electrochemical CO_(2) reduction reaction

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Journal of Energy Chemistry 2024年第6期93卷 8-15,I0001页

作者： Gyeong Ho Han Jung Yong Seo Minji Kang Myung-gi Seo Youngheon Choi Soo Young Kim Sang Hyun Ahn school of chemical engineering and Material Science Chung-Ang UniversitySeoul 06974Republic of Korea Lotte chemical Institute of Technology Daejeon 34110Republic of Korea Department of Materials Science and engineering Korea UniversitySeoul 02841Republic of Korea

Cu catalysts can convert CO_(2) through an electrochemical reduction reaction into a variety of useful carbon-based ***,this capability provides an obstacle to increasing the selectivity for a single ***,we report a simple fabrication method for a Cu-Pd alloy catalyst for use in a membrane electrode assembly(MEA)-based CO_(2) electrolyzer for the electrochemical CO_(2) reduction reaction(ECRR)with high selectivity for CO *** the composition of the Cu-Pd alloy catalyst was fabricated at 6:4,the selectivity for CO increased and the production of multi-carbon compounds and hydrogen is *** a Cu-Pd alloy catalyst with 6:4 ratio as the cathode of the MEAbased CO_(2) electrolyzer showed a CO faradaic efficiency of 92.8%at 2.4 V_(cell).We assumed that these results contributed from the crystal planes on the surface of the Cu-Pd *** phases of the Cu-Pd alloy catalyst were partially separated through annealing to fabricate a catalyst with high selectivity for CO at low voltage and C_(2)H_4 at high *** results of CO-stripping testing confirmed that when Cu partially separates from the lattice of the Cu-Pd alloy,the desorption of~*CO is suppressed,suggesting that C-C coupling reaction is favored.

关键词： Cu-Pd catalyst Electrodeposition Electrochemical carbon dioxide reduction Partial phase separation Membrane electrode assembly-based electrolyzer

Coupling effects of hydrological characteristics and nutrient load in sediments on the trophic state of reservoirs

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Acta Geochimica 2021年第4期40卷 640-649页

作者： Fan Xinyi Yue Yihong Mei Lin Li Xiaoying Hu Zhehui Luo Jiajie Liu Liu Wang Fushun school of Environmental and chemical engineering Shanghai UniversityNo.99Shangda RoadBaoshan 200444ShanghaiChina

Currently,lakes and artificial reservoirs are increasingly threatened by eutrophication,which is the result of the combined action of many natural and anthropogenic *** the past,the effect of nutrient load on the trophic state of water bodies has attracted much attention,while few studies have addressed the effect of hydrological ***,to reveal the coupling effects of hydrological characteristics and nutrient load in sediments on the trophic state of water bodies,this study collected relevant data from 36 lakes and reservoirs across *** correlation analysis showed that trophic level index was positively and significantly correlated with nutrient load in sediments and hydraulic retention time,while it was negatively correlated with mean depth and hydraulic *** principal component analysis showed that the nutrient load was the first major component that influenced the trophic state of water bodies,followed by the mean depth and hydraulic retention *** was prone to occur in water bodies with mean depth less than 7 m and hydraulic retention time greater than 14 d,and the trophic level index regression equation with hydrological characteristics and nutrient load in sediments was derived by multiple regression *** study revealed that the trophic state of water bodies influenced by both nutrient load and hydrological *** provides a new idea to reduce the occurrence of eutrophication in reservoirs by using the artificial hydrological regulation capacity of reservoirs.

关键词： Artificial reservoirs Hydrological characteristics Nutrient load Trophic state of water bodies

Development of mucoadhesive sericin/alginate particles loaded with ibuprofen for sustained drug delivery

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Particuology 2018年第6期16卷 65-73页

作者： Emanuelle D.Freitas Jacyara M.M.Vidart Edson A.Silva Meuris G.C.da Silva Melissa G.A.Vieira Department of Processes and Products Design School of Chemical EngineeringUniversity of Campinas-UNICAMPAlbert Einstein Avenue50013083-852CampinasSPBrazil school of chemical engineering State University of West Parana-UNIOESTEFaculdade Street64585903-000ToledoPRBrazil

A sericin/alginate blend was successfully applied as a matrix for incorporation of *** provided a sustained release formulation,which could improve the therapeutic efficacy of ibuprofen and patient adherence to *** increased the proportion of drug incorporated into the particles (i.e., the drug incorporation efficiency),with incorporation rates between 73.01%±1.70%and 94.15%±4.21%. Alginate affected the drug release,and the particles with the maximum alginate mass fraction tested (2.8%)showed sustained release through a dissolution mechanism,reaching equilibrium after about *** of the incorporation efficiency and the drug release time showed the best results were for formulations with a high alginate *** electron microscopy,Fourier transform infrared spectroscopy,and X-ray diffraction analysis were used for particle characterization to study the incorporation of *** particle size range was 0.80±0.13to 1.08±*** size distributions of sericin-containing particles showed a good fit with the Gaussian model.

关键词： Sericin Alginate Ibuprofen Sustained drug release

Thermally Conductive Poly(lactic acid) Composites with Superior Electromagnetic Shielding Performances via 3D Printing Technology

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Chinese Journal of Polymer Science 2022年第3期40卷 248-255,I0006页

作者： Teng-Bo Ma Hao Ma Kun-Peng Ruan Xue-Tao Shi Hua Qiu Sheng-Yuan Gao Jun-Wei Gu Shaanxi Key Laboratory of Macromolecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072China school of Materials Science and engineering Henan University of Science and TechnologyLuoyang 471023China

This work proposes a facile fabrication strategy for thermally conductive graphite nanosheets/poly(lactic acid) sheets with ordered GNPs(o-GNPs/PLA) via fused deposition modeling(FDM) 3 D printing *** combinations of o-GNPs/PLA with Ti_(3) C_(2) T_(x) films prepared by vacuum-assisted filtration were carried out by "layer-by-layer stacking-hot pressing" to be the thermally conductive Ti_(3) C_(2) T_(x)/(oGNPs/PLA) composites with superior electromagnetic interference shielding effectiveness(EMI SE).When the content of GNPs was 18.60 wt%and 4 layers of Ti_(3) C_(2) T_(x)(6.98 wt%) films were embedded,the in-plane thermal conductivity coefficient(λ_(Ⅱ)) and EMI SE(EMI SE_(Ⅱ)) values of the thermally conductive Ti_(3) C_(2) T_(x)/(o-GNPs/P LA) composites significantly increa sed to 3.44 W·m^(-1)·K^(-1) and 65 d B(3.00 mm),increased by 1223.1% and2066.7%,respectively,compared with λ_(Ⅱ)(0.26 W·m^(-1)·K^(-1)) and EMI SE_(Ⅱ)(3 d B) of neat PLA *** work offers a novel and easily route for designing and manufacturing highly thermally conductive polymer composites with superior EMI SE for broader application.

关键词： Polymer-matrix composites(PMCs) Ti_(3)C_(2)T_(x) 3D printing Thermal conductivity Electromagnetic interference(EMI)

Shape Memory Effect During Preparation of Alumia Ceramic Tubes

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Journal of Wuhan University of Technology(Materials Science) 2014年第5期29卷 869-872页

作者：钟莲云吴伯麟 school of Chemistry and chemical engineering of Guangxi University for Nationalities Key Laboratory of Chemical and Biological Transformation Process of Guangxi Higher Education Institutes College of Materials Science and engineering Guilin University of Technology

Pure alumina ceramic tube and 95 alumina ceramic （the ceramic with 95.84% alumina） tube were prepared by using self-prepared alumina micrometer powder without agglomeration as raw material. The ceramic green was shaped by isostatic pressing and sintered at different temperature from 800 to 1 600 ℃ for 2 h. The 95 ceramic tube sintered at 1 550 ℃ for 2 h had mean particle size of 4 μm, bend strength of 437 MPa and volume density of 3.714 g/cm3. Shape memory effect during sintering was observed. XRD results showed that no phase transition occurred during shape memory process, which indicated that shape memory effect was not caused by phase transition. Several probable causes of the alumina ceramic shape memory effect were discussed in this paper.

关键词： shape memory effect alumina superfine powder isostatic pressing alumina ceramic tube

Synthesis of NaY zeolite from a submolten depolymerized perlite:Alkalinity effect and crystallization kinetics

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Chinese Journal of chemical engineering 2024年第6期70卷 130-138页

作者： Yanli Qu Peng Dong Li Yang Yuanyuan Yue Haoliang Wang Jingcai Cheng Chao Yang CAS Key Laboratory of Green Process and engineering State Key Laboratory of Petroleum Molecular&Process EngineeringInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China school of chemical engineering University of Chinese Academy of SciencesBeijing 100190China Qingyuan Innovation Laboratory Quanzhou 362801China National engineering Research Center of chemical Fertilizer Catalyst College of Chemical EngineeringFuzhou UniversityFuzhou 350108China

NaY zeolites are synthesized using submolten salt depolymerized natural perlite mineral as the main silica and alumina sources in a 0.94 L stirred *** of alkalinity ranging from 0.38 to 0.55(n(Na_(2)O)/n(SiO_(2)))on the relative crystallinity,textural properties and crystallization kinetics were *** results show that alkalinity exerts a nonmonotonic influence on the relative crystallinity and textural properties,which exhibit a maximum at the alkalinity of *** nucleation kinetics are studied by fitting the experimental data of relative crystallinity with the Gualtieri *** is shown that the nucleation rate constant increases with increasing alkalinity,while the duration period of nucleation decreases with increasing *** n(Na_(2)O)/n(SiO_(2))ratios ranging from 0.38 to 0.55,the as-synthesized NaY zeolites exhibit narrower crystal size distributions with the increase in *** growth rates determined from the variations of average crystal size with time are 51.09,157.50,46.17 and 24.75 nm·h^(-1),*** is found that the larger average crystal sizes at the alkalinity of 0.38 and 0.43 are attributed to the dominant role of crystal growth over ***,the combined action of prominent crystal growth and the longer duration periods of nucleation at the alkalinity of 0.38 and 0.43 results in broader crystal size *** findings demonstrate that control of the properties of NaY zeolite and the crystallization kinetics can be achieved by conducting the crystallization process in an appropriate range of alkalinity of the reaction mixture.

关键词： NaY zeolite Submolten salt depolymerized perlite Alkalinity Crystallization kinetics

Interatomic electron transfer promotes electroreduction CO_(2)-to-CO efficiency over a CuZn diatomic site

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Nano Research 2023年第7期16卷 8863-8870页

作者： Jican Hao Han Zhu Qi Zhao Jiace Hao Shuanglong Lu Xiaofan Wang Fang Duan Mingliang Du Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnan UniversityWuxi 214122China school of Biological and chemical Sciences Queen Mary University of LondonLondon E14NSUK

Diatomic site catalysts(DACs)with two adjacent atomic metal species can provide synergistic interactions and more sophisticated functionalities to break the bottleneck of intrinsic drawbacks of single atom catalysts(SACs).Herein,we have designed a CuZn diatomic site(CuZn-DAS)electrocatalyst with unique coordination structure(CuN_(4)-ZnN_(4))by anchoring and ordering the spatial distance between the metal precursors on the carbon nitride(C_(3)N_(4))derived N-doped carbon(NC)*** CuZn-DAS/NC shows high activity and selectivity for electroreduction CO_(2)into *** Faradaic efficiency for CO of CuZn-DAS/NC(98.4%)is higher than that of Cu single atomic site on NC(Cu-SAS/NC)(36.4%)and Zn single atomic site on NC(Zn-SAS/NC)(66.8%)at-0.6 V versus reversible hydrogen electrode(***).In situ characterizations reveal that the CuZn-DAS is more favorable for the formation and adsorption of^(*)COOH than those of the electrocatalysts with single atomic *** calculations show that the charge redistribution of Zn site in CuZn-DAS/NC caused by the considerable electron transfers from Zn atoms to the adjacent Cu atoms can reduce the adsorption energy barriers for^(*)COOH and^(*)CO production,improving the activity and CO selectivity.

关键词： CuZn diatomic site CO_(2)electroreduction reaction interatomic electron transfer in situ characterizations

Improving prodeoxyviolacein production via multiplex SCRaMbLE iterative cycles

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Frontiers of chemical Science and engineering 2018年第4期12卷 806-814页

作者： Juan Wang Bin Jia Zexiong Xie Yunxiang Li Yingjin Yuan Key Laboratory of Systems Bioengineering (Ministry of Education) School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China SynBio Research Platform Collaborative Innovation Center of Chemical Science and Engineering (Tianjin)Tianjin University Tianjin 300072China

The synthetic chromosome rearrangement and modification by loxP-mediated evolution (SCRaMbLE) system has been used to improve prodeoxyviolacein (PDV) production in haploid yeast containing chromosome synV. To rapidly and continuously generate genome diversification with the desired phenotype, the multiplex SCRaMbLE iterative cycle strategy has been developed for the screening of high PDV production strains. Wholegenome sequencing analysis reveals large duplications, deletions, and even the whole genome duplications. The deletion of YER151C is proved to be responsible for the increase. This study demonstrates that artificial DNA rearrangement can be used to accelerate microbial evolution and the production of biobased chemicals.

关键词： synthetic biology genome rearrangement prodeoxyviolacein SCRaMbLE Saccharomyces cerevisiae