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具有不同活性中心的固体催化剂的失活模式(英文)

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催化学报 2011年第1期32卷 51-59页

作者： K.KUMBILIEVA L.PETROV Institute of catalysis Bulgarian Academy of Sciences sabic chair in catalysis King Abdulaziz University

An approach is suggested to distinguish different types of active sites responsible for different reactions on bifunctional *** model assumes a non-uniform vulnerability of active sites that depends on their *** on the relationship between the dispersion of the active phase and selectivity are *** effect of coke formation on the activity change of different sites is analyzed.

关键词：稳固的催化剂释放模式 bifunctional 催化剂活跃地点

Improving circulating fluidized bed dehydrogenation technology through optimization of fluidization

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Particuology 2020年第3期18卷 127-134页

作者： Mayank Kashyap Malleswara Rao Tadiboyina Christian Okolo Sami Al-Mutairi sabic Technology and Innovation SABIC14100 Southwest FreewaySuite 600Sugar LandTexas 77478USA sabic Technology Management SABICUrmonderbaan 22/6167 RdGeleenNetherlands sabic Technology Management SABICJubail Industrial CityJubail31961Saudi Arabia

The dehydrogenation of light alkanes to corresponding light olefins is an important industrial *** present work involved the assessment of a commercial alkane dehydrogenation circulating fluidized bed (CFB) reactor unit that had been underperforming and exhibiting higher than expected catalyst losses over a long period of *** aspects of this unit related to fluidization,catalysis,and process engineering were investigated to understand and resolve these *** primary focus was on the fluidization aspects of the process,along with a comparison of equipment design and operating conditions to accepted best practices in the *** designs of key equipment in the reactor and regenerator,including feed distributors,fuel gas distributors,cyclones,baffles,strippers,transfer lines,risers,riser terminations,and refractories,were studied in *** attrition rates of different types of catalysts used in the unit were also *** recommendations and improvement opportunities were proposed to significantly increase light olefins production and reduce catalyst losses,and were accepted and *** study provides insights into means of improving fluidization behavior and highlights the viability of employing a systematic approach to determine the underlying root causes of issues in a commercial CFB reactor unit.

关键词： Fluidization Circulating fluidized bed Dehydrogenation Light olefin Catalyst loss

颗粒内传质参数作为工具用于催化剂颗粒的设计(英文)

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催化学报 2012年第7期33卷 1166-1175页

作者： L. PETROV M. DAOUS Y. ALHAMED A. AL-ZAHRANI Kh. MAXIMOV sabic chair in catalysis Chemical and Materials Engineering Department Faculty of Engineering King Abdulaziz University PO Box 80204 Jeddah 21589 Kingdom of Saudi Arabia Institute of catalysis Bulgarian Academy of Sciences Sofia 1113 Bulgaria

A chromatographic method and a dynamic Wicke-Kallenbach method (DMWK) were used to determine the diffusion characteristics of two industrial copper containing catalysts. The first catalyst was used in nitrobenzene hydrogenation to aniline and the second was used in a low temperature water-gas shift reaction. Experimental results show that application of these two methods leads to similar results. Experimental data obtained allow for monitoring changes in the texture of the catalyst grains and intraparticle diffusivity of gaseous reagents at different states of the catalyst activity and use, which can be used as criteria for designing optimal industrial catalyst pellets.

关键词： effective diffusion coefficient tortuosity copper catalyst pellet design

Rational design of Pd-TiO_(2)/g-C_(3)N_(4) heterojunction with enhanced photocatalytic activity through interfacial charge transfer

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Clean Energy 2019年第1期3卷 59-68页

作者： Tayirjan Taylor Isimjan Shahid Rasul Maher Nasser Aloufi Mohd Adnan Khan Ibrahim Khalid Alhowaish Toseef Ahmed Fundamental catalysis SABIC-CRD at KAUSTThuwalSaudi Arabia King Abdullah University of Science and Technology(KAUST) Physical Science and Engineering DivisionThuwal23955-6900Saudi Arabia sabic Technology Center RiyadhSaudi Arabia

A hybrid heterojunction-based photocatalyst is synthesized by an electrostatic self-assembly strategy including surface modification and controlled metal *** interfacial contact was made by mixing negatively charged anatase TiO_(2) nanoparticles with positively charged ***-light deposition of Pd nanoparticles largely on TiO_(2) was made possible due to the charge transfer from C_(3)N_(4)(excited by visible light)to the conduction band of TiO_(2) reducing Pd ions on contact with its *** order to further test the efficiency of this cascade of electron transfer across the conduction bands of the two semiconductors,photocatalytic H2 production from water was *** optimizing the ratio of the two semiconductors,increased H2 production rates were observed and attributed to enhanced charge *** were studied by a variety of techniques in order to probe into their properties and link them to *** reaction rate,under visible-light excitation,of the best sample showed an 8-fold enhancement when compared to that of Pd-C_(3)N_(4) in identical conditions and the highest apparent quantum yield of 31%was achieved by a 0.1% Pd/20%TiO_(2)/C_(3)N_(4) sample in a 420-to 443-nm range.

关键词： surface charge heterojunction photocatalyst electrostatic self-assembly hydrogen generation

Nanodispersed Oxides-Plasma-Chemical Synthesis and Properties

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Plasma Science and Technology 2007年第5期9卷 603-610页

作者： Gheorghi VISSOKOV Katerina ZAHARIEVA Institute of catalysis Bulgarian Academy of SciencesSofia 1113Bulgaria Chemistry chair St.Ivan Rilski University of Mining and GeologySofia 1700Bulgaria

We discuss the plasma-chemical synthesis and the properties of transition metals oxides, Al2O3, SiO2, rare-earth oxides, oxides for ceramics and metal-ceramics, and oxides used as catalysts. Bearing in mind the indisputable advantages of using plasma-chemically synthesized nanodispersed oxides for the needs of various industrial fields, we set out to review the articles published in the past few years devoted to the problems of plasma-chemical synthesis and characterization of nanodispersed oxides.

关键词： plasma synthesis nanodispersed oxides properties

Catalytic performances of Ni/mesoporous SiO_2 catalysts for dry reforming of methane to hydrogen

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Journal of Energy Chemistry 2016年第4期25卷 709-719页

作者： Fei Huang Rui Wang Chao Yang Hafedh Driss Wei Chu Hui Zhang College of Chemistry and Chemical Engineering Southwest Petroleum University Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province Drilling & Production Engineering Technology Research Institute CNPC Chuanqing Drilling Engineering Co.Ltd. sabic chair in catalysis King Abudulaziz University Department of Chemical Engineering Sichuan University

Several mesoporous silicas with different morphologies were controllably prepared by sol-gel method with adjustable ratio of dual template, and they were further impregnated with aqueous solution of nickel nitrate, followed by calcination in air. The synthesized silica supports and supported nickel samples were characterized using N2-adsorption/desorption, X-ray diffraction (XRD), H2temperature-programmed reduction (H2-TPR), Scanning electron microscope (SEM), Transmission electron microscope (TEM) and thermo-gravimetric analysis (TGA-DTG) techniques. The Ni nanoparticles supported on shell-like silica are highly dispersed and yielded much narrower nickel particle-size than those on other mesoporous silica. The methane reforming with dioxide carbon reaction results showed that Ni nanoparticles supported on shell-like silica carrier exhibited the better catalytic performance and catalytic stability than those of nickel catalyst supported on other silica carrier. The thermo-gravimetric analysis on used nickel catalysts uncovered that catalyst deactivation depends on the type and nature of the coke deposited. The heterogeneous nature of the deposited coke was observed on nickel nanoparticles supported on spherical and peanut-like silica. Much narrower and lower TGA derivative peak was founded on Ni catalyst supported on the shell-like silica. © 2016 Science Press

关键词： Carbon Catalyst activity Catalyst deactivation Catalysts Catalytic reforming Coke Gravimetric analysis Hydrogen Methane Nanoparticles Nickel Particle size Scanning electron microscopy Silica Sol gel process Sol gels Solutions Thermogravimetric analysis Transmission electron microscopy X ray diffraction

The Pichia pastoris enzyme production platform:From combinatorial library screening to bench-top fermentation on residual cyanobacterial biomass

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Journal of Bioresources and Bioproducts 2024年第1期9卷 43-57页

作者： Korbinian Sinzinger Ulrike Obst Samed Güner Manuel Döring Magdalena Haslbeck Doris Schieder Volker Sieber chair of Chemistry of Biogenic Resources Campus Straubing for Biotechnology and SustainabilityTechnical University of MunichStraubing 94315Germany catalysis Research Center Technical University of MunichGarching 85748Germany SynBiofoundry@TUM Technical University of MunichStraubing 94315Germany School of Chemistry and Molecular Biosciences The University of QueenslandSt.Lucia 4072Australia

The demand for industrial enzymes is continually rising,fueled by the growing need to shift towards more sustainable industrial ***,making efficient enzyme production strains and identifying optimal enzyme expression conditions remains a ***,the production of the enzymes themselves comes with unavoidable impacts,e.g.,the need to utilize secondary ***,we take a more holistic view of bioprocess development and report an integrative approach that allows us to rapidly identify improved enzyme expression and secretion conditions and make use of cyanobacterial waste biomass as feed for supporting Pichia pastoris *** demonstrate these capabilities by producing a phytase secreted by *** that is grown on cyanobacterium hydrolysate and buffered glycerol-complex(BMGY)medium,with genetic expression conditions identified by high-throughput screening of a randomized se-cretion *** our best-performing strain is grown in a fed-batch fermentation on BMGY,we reach over 7000 U/mL in three days.

关键词： Protein secretion Phytase Cyanobacterial biomass Fed-batch fermentation Pichia pastoris

Diagnosing Battery Degradation via Gas Analysis

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Energy & Environmental Materials 2022年第3期5卷 688-692页

作者： Michael Metzger Hubert A.Gasteiger Department of Physics and Atmospheric Science Dalhousie UniversityHalifax Nova Scotia B3H 4R2Canada Department of Chemistry Dalhousie UniversityHalifax Nova Scotia B3H 4R2Canada chair of Technical Electrochemistry Department of Chemistry and Catalysis Research CenterTechnical University of MunichD-85748Garching Germany

Interfacial reactions in lithium-ion batteries often involve gaseous reaction *** investigation of material degradation processes requires a technique to identify and quantify these gases in battery *** electrochemical mass spectrometry(OEMS)is an operando gas analysis method that continuously samples the headspace of a custom battery ***-time gas analysis by quantitative OEMS was used to create mechanistic understanding of battery degradation reactions,some of which will be highlight in this article.

关键词： aging mechanisms batteries energy storage gas analysis in situ and operando characterization

Electrosorption at metal surfaces from first principles

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npj Computational Materials 2020年第1期6卷 517-526页

作者： Nicolas G.Hörmann Nicola Marzari Karsten Reuter chair of Theoretical Chemistry and catalysis Research Center Technische Universität MünchenGarching 85748Germany Theory and Simulation of Materials(THEOS) and National Centre for Computational Design and Discovery of Novel Materials(MARVEL)École Polytechnique Fédérale de LausanneLausanne 1015Switzerland Fritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4-6Berlin 14195Germany

Electrosorption of solvated species at metal electrodes is a most fundamental class of processes in interfacial ***,we use its sensitive dependence on the electric double layer to assess the performance of ab initio thermodynamics approaches increasingly used for the first-principles description of *** show analytically that computational hydrogen electrode calculations at zero net-charge can be understood as a first-order approximation to a fully grand canonical ***,higher-order terms in the applied potential caused by the charging of the double layer include contributions from adsorbate-induced changes in the work function and in the interfacial *** contributions are essential to yield prominent electrochemical phenomena such as non-Nernstian shifts of electrosorption peaks and non-integer electrosorption *** illustrate this by calculating peak shifts for H on Pt electrodes and electrosorption valencies of halide ions on Ag electrodes,obtaining qualitative agreement with experimental data already when considering only second order *** results demonstrate the agreement between classical electrochemistry concepts and a first-principles fully grand canonical description of electrified interfaces and shed new light on the widespread computational hydrogen electrode approach.

关键词： sorption principles canonical