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Co-aromatization of methane and hexane over Pt encapsulated in ZSM-5 zeolite and the electronic effect of K promoters

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Science China Chemistry 2024年第3期67卷 1017-1027页

作者： Bei Liu Fan Wang Xiaomeng Dou Pengfei Li Hongwei Xiang Yong Yang Peng He State Key Laboratory of Coal Conversion Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001China department of Chemistry Tsinghua UniversityBeijing 100084China National Energy R&D Center for Coal to Liquid Fuels Synfuels China Technology Co.Ltd.Beijing 101407China university of Chinese Academy of Sciences Beijing 101408China Leibniz-Institut für Katalyse e.V.an der Universitat rostock Rostock 18059Germany

The co-aromatization of methane with higher hydrocarbons represents a promising route to valorize methane, an abundant but underexploited carbon resource. In this study, we elucidate a novel approach to enhance the catalytic co-aromatization of hexane and methane by confining Pt within zeolite catalysts and modulating its electron density. Our findings show that encapsulating Pt within MFI structure is pivotal for activating the feedstock and fostering the formation of aromatic products. Interaction between K atoms and the silanol nest forms siloxy groups which are critical for the stabilization of Pt species. Tuning the K content in PtSn@MFI catalysts adeptly alters the electronic configuration of Pt clusters. This modification is corroborated by infrared and X-ray photoelectron spectroscopy analysis, and density functional theory calculations. Remarkably, the catalyst with 0.8 wt% K exhibits an optimal Pt electron density, driving its superior efficacy in the co-aromatization reaction, converting 0.78 mol of methane for each mole of hexane processed. By employing ~(13)C isotopic labeling and solid-state NMR studies, we demonstrate the participation of methane in the adsorbed species inside the zeolite channel and its incorporation to the benzyl site of the substitute group and phenyl rings in aromatic compounds, underscoring the importance of Pt encapsulation.

关键词： Pt encapsulation MFI zeolite methane activation co-aromatization ^(13)C solid-state NMR

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Realizing methanol synthesis from CO and water via the synergistic effect of Cu^(0)/Cu^(+)over Cu/ZrO_(2) catalyst

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Journal of Energy Chemistry 2024年第6期93卷 126-134,I0004页

作者： Yuan Fang Fan Wang Yang Chen Qian Lv Kun Jiang Hua Yang Huibo Zhao Peng Wang Yuyan Gan Lizhi Wu Yu Tang Xinhua Gao Li Tan Institute of Molecular Catalysis and In Situ/Operando Studies Fujian Key Laboratory of Electrochemical Energy Storage MaterialsState Key Laboratory of Photocatalysis on Energy and EnvironmentCollege of ChemistryFuzhou UniversityFuzhou 350108FujianChina Leibniz-Institut für Katalyse e.V.an der Universität rostock Albert-Einstein Strasse 9118059 RostockGermany department of Chemistry Tsinghua UniversityBeijing 100084China State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering College of Chemistry and Chemical EngineeringNingxia UniversityYinchuan 750021Ningxi1China

The optimizing utilization of ca rbon resources has drawn wide attention all over the world,while exploiting the high-efficiency catalytic routes remains a ***,a direct methanol synthesis route is realized from pure CO and H_(2)O over 10%Cu/t-ZrO_(2) catalyst,where the time yield of methanol is144.43 mmol mol_(Cu)^(-1)h^(-1)and the methanol selectivity in hydrocarbons is 100%,The Cu species highly dispersed in the t-ZrO_(2) support lead parts of them in the cationic *** Cu^(+)sites contribute to the dissociation of H_(2)O,providing the H*source for methanol synthesis,while the formed Cu^(0) sites promote the absorption and transfer of H*during the ***,the H_(2)O is even a better H resource than H_(2) due to its better dissociation effectivity in this catalytic *** present work offers a new approach for methanol synthesis from CO and new insight into the process of supplying H donor.

关键词： H_(2)O CO Methanol Cu-based catalysts t-ZrO_(2)

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Exploring the Predominant Factors Influencing the Oxygen Reduction Performance of PtCo/C Catalysts

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Chemical Research in Chinese Universities 2024年第4期40卷 753-760页

作者： LI Jinrong YU Xianghui SUN Qi PENG Yong CAO Shuang HOU Chun-Chao XU Qiang College of Chemistry and Chemical Engineering Institute for Sustainable Energy and ResourcesQingdao UniversityQingdao266071P.R.China Leibniz Institute for Catalysis e.V. Albert-Einstein-Strasse 29aRostock18059Germany School of Materials Science and Engineering Ocean University of ChinaQingdao266100P.R.China Shenzhen Key Laboratory of Micro/Nano-Porous Functional Materials(SKLPM) SUSTech-Kyoto University Advanced Energy Materials Joint Innovation Laboratory(SKAEM-JIL)Key University Laboratory of Highly Efficient Utilization of Solar Energy and Sustainable Development of GuangdongDepartment of Chemistry and Department of Materials Science and EngineeringSouthern University of Science and Technology(SUSTech)Shenzhen518055P.R.China

PtCo nanoalloys(NAs)deposited on carbon black are emerging as robust electrocatalysts for addressing the sluggish kinetic issue of oxygen reduction reaction(ORR).However,developing a simple and low-cost method to synthesize PtCo/C with excellent performance is still a great *** this work,a one-pot method was used to successfully obtain the PtCo NAs on commercial carbon supports of acetylene black and Ketjenblack ECP600JD,*** with those grown on Ketjenblack ECP600JD,the PtCo NAs grown on acetylene black exhibited higher electrochemical surface area(ECSA)and mass activity(MA),which may be attributed to the different particle sizes of PtCo NAs,distinct hydrophilicity,electroconductivity and charge distribution between the carbon supports and PtCo *** study provides valuable insights into the optimal design of carbon-supported ORR electrocatalysts with exceptional activity and durability.

关键词： Oxygen reduction reaction PtCo nanoalloy Carbon-supported nanostructure Acetylene black

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Mixing Enhancement in a Coaxial Jet Mixer

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Advances in Materials Physics and Chemistry 2012年第4期2卷 134-137页

作者： Valery Zhdanov Egon Hassel rostock university department of technical thermodynamics 18059 rostock Germany rostock university department of technical thermodynamics 18059 rostock Germany

Experimental investigations of mixing in a coaxial jet mixer have been carried out applying Particle Image Velocimetry (PIV) and Planar Laser Induced Fluorescence (PLIF) methods simultaneously. A developed turbulent jet of an aqueous solution of Rhodamine 6G issued from the nozzle was mixed with co-flow water. Velocity and scalar fields were studied quite far downstream flow to control the formation of a quasi homogeneous mixture. The intensity of mixing was varied by mouthpieces with rectangular and triangular vortex generators of different sizes installed in the nozzle. The formation length of the quasi homogeneous mixture was reduced about 10 jet diameters by the tabs. The triangular tabs were more effective than the rectangular ones.

关键词： Mixing Turbulent Flow Vortex Generators PIV PLIF

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High-silica faujasite zeolite-tailored metal encapsulation for the low-temperature production of pentanoic biofuels

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Journal of Energy Chemistry 2024年第1期88卷 552-560,I0012页

作者： Wenhao Cui Yuanshuai Liu Pengfei Guo Zhijie Wu Liqun Kang Huawei Geng Shengqi Chu Linying Wang Dong Fan Zhenghao Jia Haifeng Qi Wenhao Luo Peng Tian Zhongmin Liu National Engineering Research Center of Lower-Carbon Catalysis Technology Dalian National Laboratory for Clean EnergyDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina university of Chinese Academy of Sciences Beijing 100049China Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of SciencesQingdao 266101ShandongChina College of Chemistry and Chemical Engineering Inner Mongolia UniversityHohhot 010021Inner MongoliaChina State Key Laboratory of Heavy Oil Processing and Key Laboratory of Catalysis of CNPC China University of PetroleumBeijing 102249China department of Inorganic Spectroscopy Max Planck Institute for Chemical Energy ConversionMülheim an der Ruhr 45470Germany Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Division of Energy Research Resources Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina Leibniz-Institut für Katalyse Albert-Einstein-Straβe 29aRostock 18059Germany

Zeolite-encapsulated metal nanoclusters are at the heart of bifunctional catalysts,which hold great potential for petrochemical conversion and the emerging sustainable ***,efficient encapsulation of metal nanoclusters into a high-silica zeolite Y in particular with good structural integrity still remains a significant ***,we have constructed Ru nanoclusters(~1 nm)encapsulated inside a high-silica zeolite Y(SY)with a SiO_(2)/Al_(2)O_(3) ratio(SAR)of 10 via a cooperative strategy for direct zeolite synthesis and a consecutive impregnation for metal *** with the benchmark Ru/H-USY and other analogues,the as-prepared Ru/H-SY markedly boosts the yields of pentanoic biofuels and stability in the direct hydrodeoxygenation of biomass-derived levulinate even at a mild temperature of 180℃,which are attributed to the notable stabilization of transition states by the enhanced acid accessibility and properly sized constraints of zeolite cavities owing to the good structural integrity.

关键词： High-silica zeolite Y Metal encapsulation Bifunctional catalysis Hydrodeoxygenation Biofuels

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Development of an early warning information infrastructure using spatial web services technology

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International Journal of Digital Earth 2010年第4期3卷 384-394页

作者： Kai Walter department of Geodesy and Geoinformatics Institute for Management of Rural AreasFaculty of Agricultural and Environmental SciencesRostock UniversityJustus-von-Liebig-Weg 618059RostockGermany

Current high-performance monitoring and early warning systems are compara-tively expensive and *** project described here aims for a systematic development of a prototypical alarm and early warning system for landslides utilising low-cost ad hoc wireless sensor networks and flexible spatial web service *** web-based services as tools to exchange environmental data is an important step towards addressing today’s larger scale environmental *** project’s information system functions for notification,data access and analysis are implemented utilising Open Geospatial Consortium web service *** to implementing the orchestration of operation workflows and production of near real-time information products are illustrated.

关键词： early warning wireless sensor network Sensor Web Enablement digital earth OGC SLEWS

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Medicinal uses,phytochemistry and pharmacology of Picralima nitida(Apocynaceae) in tropical diseases:A review

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Asian Pacific Journal of Tropical Medicine 2014年第1期7卷 1-8页

作者： Osayemwenre Erharuyi Abiodun Falodun Peter Langer Institute of Chemistry University of RostockAlbert-Einstein-Str.3A18059 RostockGermany department of Pharmacognosy School of PharmacyUniversity of Mississippi38655 OxfordMississippiUSA

Picralima nitida Durand and Hook,(***)is a West African plant with varied applications in African folk *** parts of the plant have been employed ethnomedicinally as remedy for fever,hypertension,jaundice,dysmenorrheal,gastrointestinal disorders and *** order to reveal its full pharmacological and therapeutic potentials,die present review focuses on the current medicinal uses,phytochemistry,pharmacological and toxicological activities of this *** survey on scientific journals,books as well as electronic sources have shown the isolation of alkaloids,tannins,polyphenols and steroids from different parts of the plant,pharmacological studies revealed that the extract or isolated compounds from this species posses analgesic,anti-inflammatory,hypoglyceamic,hypotensive,antiplasmodial,antimicrobial,antiulcer and antitumorigenic *** from various scientific investigations to date have revealed the potential of the extract from the plant or isolated compounds for use in the treatment and prevention of various kinds of human ***,further studies on the extracts and pure compounds from this species is required to completely assess its phytoc-hemical,pharmacological and toxicological profile as well as the mechanism of action behind these pharmacological activities exhibited by the compounds isolated from this species.

关键词： Picralima nitida Apocynaceae Phytochemistry Pharmacology

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Frequency Stability of Power System with Large Share of Wind Power Under Storm Conditions

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Journal of Modern Power Systems and Clean Energy 2020年第2期8卷 219-228页

作者： Kaushik Das Feng Guo Edgar Nuno Nicolaos A.Cutululis the department of Wind Energy Technical University of Denmark(DTU)RiseDenmark Suzlon Energy Limited RostockGermany

The operation of transmission systems with large share of wind power is specially challenging under storm *** the stormy wind speed conditions,wind turbine protection system is designed to shut down the turbine to avoid excessive mechanical *** sudden loss of wind power from large offshore plants is difficult to forecast accurately,which results in a large amount of power *** severity of such a wind power imbalance towards frequency stability needs to be studied for the future power *** addition,the overhead transmission lines can also be affected during storms,thereby increasing their probability of failure in the operation of power system under the islanded *** paper investigates how the stormy weather can threaten the frequency stability of future Danish power system with large share of wind power and how to avoid the frequency instability through proper control and defence strategies such as high-voltage direct current(HVDC)control and load *** studies are performed for ramp rates of HVDC control,load shedding strategies,inertia of the system with different volumes of disturbances to understand their impact on frequency stability.

关键词： Emergency control frequency stability storm security wind power

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Ionic self-diffusion coefficient and shear viscosity of high-Z materials in the hot dense regime

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Matter and Radiation at Extremes 2021年第2期6卷 8-16页

作者： Yong Hou Yang Jin Ping Zhang Dongdong Kang Cheng Gao Ronald Redmer Jianmin Yuan department of Physics College of Liberal Arts and SciencesNational University of Defense TechnologyChangsha 410073People’s Republic of China Institute of Physics University of RostockA.-Einstein-Strasse 23–24D-18059 RostockGermany Graduate School China Academy of Engineering PhysicsBeijing 100193People’s Republic of China

High-Zmaterials exhibit a broad range of variation of the charge state in the hot dense regime,and so ionic structures becomecomplexwith increasing density and temperature owing to *** high-Z uranium as example,we study its electronic and ionic structures in the hot dense regime by combining an average-atommodelwith the hypernetted chain *** electronic structure is described by solving theDirac equation,taking account of relativistic effects,including broadening of the energy levels,and the effect of other ions via correlation *** the basis of the electronic distribution around a nucleus,the ion pair potential is constructed using the modified Gordon–Kim model in the frame of temperaturedependent density functional *** of the presence of ion–ion strong coupling,the bridge function is included in the hypernetted chain approximation,whichis usedto calculate the correlation *** take account of the influenceon transportpropertiesof the strong correlation of electrons with highly charged ions,we perform both classical and Langevin molecular dynamics simulations to determine ion self-diffusion coefficients and the shear viscosity,using theGreen–Kubo relation and an ion–ion pair potential with good *** show that the influence of electron–ion collisions on transport properties becomes more important as the free electron density increases owing to thermal ionization.

关键词： regime viscosity diffusion

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Beyond Pure Frequency and Phases Exploiting： Color Influence in SSVEP Based on BCl

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Computer Technology and Application 2014年第2期5卷 111-118页

作者： Mustafa Aljshamee Mahdi Q. Mohammed Riaz-U1-Ahsan Choudhury Abbas Malekpour Peter Luksch department of Computer Science University of Rostock Rostock 18059 Germany

A BCI （brain computer interface） established a new direct communication channel using the brain activity between the human brain and machine. The visual stimulus with a certain frequency is present to the BCI users; it exists in a particular condition to observe a continuous brain response respect to frequent of visual stimuli. A significant problem when engaged the SSVEP （steady-state visual evoked potential） based on BCI, it will be exhausted and may suffer for the users when staring at flashing stimuli. This experimental study investigates how the differences in LED＇s-colors influence of SSVEP with respect to （i.e., frequencies and phases）. The result shows that the visualization of phase delays in lower frequencies greater than in higher frequencies.

关键词： SSVEP BCI EEG (electroencephalograms) FFT (fast fourier transform) ERP (event related potential) FPGA (fieldprogrammable gate array) LED (light emitting diode).

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