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An Automated,Highly Selective reaction Monitoring Instrument Using Molecular Rotational Resonance Spectroscopy

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Precision Chemistry

Precision Chemistry 2024年第2期2卷 57-62页

作者： Ann Adele Byars Khushi R.Kompally Emily Mechnick Reilly E.Sonstrom Alexander Mikhonin Justin L.Neill Ruth Boetzel James MacGregor Courtney Talicska Jian Li Yizhou Liu BrightSpec Inc.CharlottesvilleVirginia 22903United States Pfizer R&D UK Limited Sandwich CT139NJUnited Kingdom Analytical Research and Development Pfizer Research and DevelopmentGrotonConnecticut 06340United States

Online monitoring of chemical reactions by using analytical chemistry tools is a powerful way to maximize control over these processes.In this paper,we demonstrate the use of molecular rotational resonance,an emerging and extraordinarily selective spectroscopic technique,to perform automated reaction monitoring measurements.An interface using a six-port valve with a calibrated sample loop,coupled to a temperature controlled inlet for analyte volatilization,was developed and tested.Two reactions were chosen for initial characterization:an amine-aldehyde condensation reaction to form an imine product and an isotopic exchange reaction of aβ-ketoester with keto-enol tautomerization.The spectrometer was able to provide kinetic information about the reaction and determine reaction completion.In the future,this system can be extended to detect and quantify impurities and characterize reaction selectivity,in addition to the reaction progress.

关键词： molecular rotational resonance spectroscopy reaction monitoring reaction kinetics isotopes process analytical technology

kinetics and mechanism of titanium hydride powder and aluminum melt reaction

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International Journal of Minerals,Metallurgy and Materials 2012年第2期19卷 165-172页

作者： Ali Rasooli Mehdi Divandari Hamid Reza Shahverdi Mohammad Ali Boutorabi School of Metallurgy and Materials Engineering Member of Center of Excellence for Advanced Material and Processing (CEAMP) Iran University of Science and Technology Tehran 16844 Iran Department of Materials Faculty of Engineering Tarbiat Modaress University Tehran 14115-143 Iran

Based on the measurement of the released hydrogen gas pressure （PH2）, the reaction kinetics between TiH2 powder and pure aluminum melt was studied at various temperatures. After cooling the samples, the interface of TiH2 powder and aluminum melt was studied. The results show that the-time curves have three regions; in the first and second regions, the rate of reaction conforms zero and one order, respectively; in the third region, the hydrogen gas pressure remains constant and the rate of reaction reaches zero. The main factors that control the rate of reaction in the first and second regions are the penetration of hydrogen atoms in the titanium lattice and the chemical reaction between molten aluminum and titanium, respectively. According to the main factors that control the rate of reaction, three temperature ranges are considered for the reaction mechanism：（a） 700-750°C, （b） 750-800°C, and （c） 800-1000°C. In the first temperature range, the reaction is mostly under the control of chemical reaction; at the temperature range of 750 to 800°C, the reaction is controlled by the diffusion and chemical reaction; at the third temperature range （800-1000°C）, the dominant controlling mechanism is diffusion.

关键词： titanium hydride aluminum reaction kinetics reaction rate constants

reaction kinetics OVER PRECIPITATED Fe/Mn/K CATALYST FOR THE FISCHER-TROPSCH SYNTHESIS

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Journal of Energy Chemistry 1995年第3期 311-319页

作者： SHEN Wen-Jie YAN Shi-Run ZHOU Jing-Lai ZHANG Bi-JiangInstitute of Coal Chemistry, Academia Sinica Taiyuan, Shanxi 030001

The kinetics of the Fischer-Tropsch Synthesis reaction is studied in an internally recycled reactor (CSTR) over a commercial, precipitated Fe/Mn/K catalyst. Kinetic data are obtained with 1 47-4.04 H2/CO feed gas over a temperature range of 265-320℃, a pressure range of 1.0-2.6 MPa, and a space velocity range of 300-800 h-1 . The kinetic model which fits the experimental data well is the same as that of the intrinsic kinetics, i.e. -RH2+CO=kPH2PCO/(PCO+bPH2O, where k is the kinetic constant for the rate-determining step and b is a function of temperature only. This model may be derived by assuming that the rate-determining step is the hydrogenation of adsorbed CO according to the enol mechanism. It is found that the CO usage ratio is probably independent of synthesis gas conversion and total pressure, and the catalyst shows high water-gas-shift activity.

关键词： Fischer-Tropsch Synthesis reaction kinetics Fe/Mn/K catalyst

Multi-Dimensional Composite Frame as Bifunctional Catalytic Medium for Ultra-Fast Charging Lithium-Sulfur Battery

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Nano-Micro Letters 2022年第12期14卷 91-105页

作者： Shuhao Tian Qi Zeng Guo Liu Juanjuan Huang Xiao Sun Di Wang Hongcen Yang Zhe Liu Xichao Mo Zhixia Wang Kun Tao Shanglong Peng National and Local Joint Engineering Laboratory for Optical Conversion Materials and Technology School of Materials and EnergyLanzhou UniversityLanzhou 730000People’s Republic of China School of Physical Science and Technology Lanzhou UniversityLanzhou 730000People’s Republic of China

The shuttle effect of soluble lithium polysulfides(LiPSs)between electrodes and slow reaction kinetics lead to extreme inefficiency and poor high current cycling stability,which limits the commercial application of Li-S batteries.Herein,the multi-dimensional composite frame has been proposed as the modified separator(MCCoS/PP)of Li-S battery,which is composed of CoS_(2) nanoparticles on alkali-treated MXene nanosheets and carbon nanotubes.Both experiments and theoretical calculations show that bifunctional catalytic activity can be achieved on the MCCoS/PP separator.It can not only promote the liquid-solid conversion in the reduction process,but also accelerate the decomposition of insoluble Li_(2)S in the oxidation process.In addition,LiPSs shuttle effect has been inhibited without a decrease in lithium-ion transference numbers.Simultaneously,the MCCoS/PP separator with good LiPSs adsorption capability arouses redistribution and fixing of active substances,which is also beneficial to the rate performance and cycling stability.The Li-S batteries with the MCCoS/PP separator have a specific capacity of 368.6 mAh g^(−1) at 20C,and the capacity decay per cycle is only 0.033%in 1000 cycles at 7C.Also,high area capacity(6.34 mAh cm^(−2))with a high sulfur loading(7.7 mg cm^(−2))and a low electrolyte/sulfur ratio(7.5μL mg^(−1))is achieved.

关键词： MXenes Transition metal sulfides Lithium-ion transference Bifunctional catalysis reaction kinetics

Oxidation of diclofenac by potassium ferrate(Ⅵ): reaction kinetics and toxicity evaluation

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Oxidation of diclofenac by potassium ferrate(Ⅵ): Reaction k...

Active phase morphology engineering of NiMo/Al2O3 through La introduction for boosting hydrodesulfurization of 4,6-DMDBT

河南省化学会2016年学术年会

作者： Yingling Wang Youhai Xie Haijin Liu Guoguang Liu Key Laboratory of Medical Molecular Probes School of Basic Medical Sciences Xinxiang Medical University School of Environment Henan Normal University Key Laboratory for Yellow River and Huaihe River Water Environment and Pollution Control

Diclofenac(DCF), a synthetic non-steroidal anti-inflammatory drug, is widely detected in ambient surface water and sewage treatment effluent. There is a growing concern regarding the persistence of DCF in the environment and its potential adverse impacts. Thus, it will be a serious threat to public health and ecosystems if drinking water sources are contaminated with DCF.Ferrate(Ⅵ) has been widely used in potable water treatment due to its triple functions as an oxidant,coagulant and disinfectant. Although ferrate is a currently utilized as an oxidant for the removal of micropollutants from aqueous media, the degradation of DCF by Fe(Ⅵ) has rarely been investigated.Furthermore, further studies are required to assess the changes in toxicity of the reaction solutions.In this work, the reaction kinetics and toxicity of diclofenac(DCF) oxidation by ferrate(Ⅵ) under simulated water disinfection conditions were investigated. Experimental results indicated that the reaction between DCF and Fe(Ⅵ) followed first-order kinetics with respect to each reactant.Furthermore, the effects of p H and temperature on DCF oxidation by Fe(Ⅵ) were elucidated via a systematic examination. The apparent second-order rate constants(kapp) increased significantly from2.54 to 11.6 M s, as the p H of the solution decreased from 11.0 to 7.0, and the acid-base equilibriums of Fe(Ⅵ) and DCF were proposed to explain the p H dependence of kapp. The acute toxicity of DCF solution during Fe(Ⅵ) oxidation was evaluated using a Microtox bioassay. Overall, the DCF degradation process resulted in a rapid increase of the inhibition rate of luminescent bacteria. These toxicity tests suggest that the formation of enhanced toxic intermediates during the Fe(Ⅵ) disinfection process may pose potential health risk to consumers.

关键词： Diclofenac Ferrate（Ⅵ） reaction kinetics Toxicity

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Petroleum Science 2023年第2期20卷 1231-1237页

作者： Ji-Xing Liu Xiang-Qi Liu Ri-Xin Yan Ling-Feng Ji Hui-Fang Cheng Hui Liu Yan Huang Ming-Qing Hua Hua-Ming Li Wen-Shuai Zhu School of Chemistry and Chemical Engineering and Institute for Energy Research Jiangsu UniversityZhenjiangJiangsu 212013China State Key Laboratory of Heavy Oil Processing and Beijing Key Lab of Oil&Gas Pollution Control China University of PetroleumBeijing 102249China State Key Laboratory of Fine Chemicals Dalian University of TechnologyDalianLiaoning 116024China

Herein,we designed and constructed a mesoporous LaAlOx via a solvent evaporation induced self-assembly protocol.The structure and physicochemical property of the corresponding NiMo supported catalyst was analyzed by a set of characterizations,and its catalytic activity was investigated for hydrodesulfurization(HDS)of 4,6-dimethyldibenzothiophene.It has confirmed that the incorporation of La profoundly facilitate the generation of“Type II”NiMoS phase by weakening the interaction of Mo–O–Al leakage and promoting the sulfidation of both Ni and Mo oxides as well as changing the morphology of Ni promoted MoS2 slabs,thereafter boosting the HDS performance substantially.The finding here may contribute to the fundamental understanding of structure-activity in ultra-deep desulfurization and inspire the advancement of highly-efficient HDS catalyst in future.

关键词： NiMo supported Catalyst LaAlOx composites Hydrodesulfurization Morphology reaction kinetics

Insight into the green route to dimethyl succinate by direct esterification of bio-based disodium succinate using CO_(2)and CH_(3)OH

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Chinese Journal of Chemical Engineering 2023年第12期64卷 188-195页

作者： Yu-Gao Wang Xiao-Chen Han Bao Gu Hua-Shuai Wu Jun Shen School of Chemical Engineering and Technology Taiyuan University of TechnologyTaiyuan 030024China

The fermentation for succinic acid production outperforms other methods by low energy consumption and environmental benignity,with the resulting products mainly as disodium succinate(DSA).By directly esterifying DSA using CO_(2) and CH3OH,it is expected to avoid the use of inorganic acids.By high-resolution mass spectrometry analysis and theoretical calculation,this study establishes that the reaction consists of three steps,i.e.,first forming 3-carboxypropanoate,then monomethyl succinate(MMS),and finally dimethyl succinate(DMS).A detailed kinetic analysis is further performed,the results demonstrate that the transformation of DSA to MMS is regarded to be a second-order reaction for reactant DSA,while the transformation of MMS to DMS is a first-order reaction for reactant MMS.The activation energy for the generation of MMS from DSA is 37.15 kJ·mol^(-1),and that for the generation of DMS from MMS is 85.80 kJ·mol^(-1),indicating the latter one is the rate-determining step.

关键词： Succinate Carbon dioxide Direct esterification reaction mechanism reaction kinetics Kinetic modeling

Is a catalyst always beneficial in plasma catalysis? Insights from the many physical and chemical interactions

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Journal of Energy Chemistry 2023年第10期85卷 501-533,I0013页

作者： Björn Loenders Roel Michiels Annemie Bogaerts Research group PLASMANT Department of ChemistryUniversity of AntwerpUniversiteitsplein 1B-2610 Wilrijk-AntwerpBelgium

Plasma-catalytic dry reforming of CH_(4)(DRM) is promising to convert the greenhouse gasses CH_(4) and CO_(2) into value-added chemicals, thus simultaneously providing an alternative to fossil resources as feedstock for the chemical industry. However, while many experiments have been dedicated to plasma-catalytic DRM, there is no consensus yet in literature on the optimal choice of catalyst for targeted products,because the underlying mechanisms are far from understood. Indeed, plasma catalysis is very complex,as it encompasses various chemical and physical interactions between plasma and catalyst, which depend on many parameters. This complexity hampers the comparison of experimental results from different studies, which, in our opinion, is an important bottleneck in the further development of this promising research field. Hence, in this perspective paper, we describe the important physical and chemical effects that should be accounted for when designing plasma-catalytic experiments in general, high-lighting the need for standardized experimental setups, as well as careful documentation of packing properties and reaction conditions, to further advance this research field. On the other hand, many parameters also create many windows of opportunity for further optimizing plasma-catalytic systems.Finally, various experiments also reveal the lack of improvement in plasma catalysis compared to plasma-only, specifically for DRM, but the underlying mechanisms are unclear. Therefore, we present our newly developed coupled plasma-surface kinetics model for DRM, to provide more insight in the underlying reasons. Our model illustrates that transition metal catalysts can adversely affect plasmacatalytic DRM, if radicals dominate the plasma-catalyst interactions. Thus, we demonstrate that a good understanding of the plasma-catalyst interactions is crucial to avoiding conditions at which these interactions negatively affect the results, and we provide some recommendations for improvement. For instance, we believe that plasma-

关键词： Plasma catalysis Dry reforming of methane Discharges reaction kinetics Modelling

Review on modification routes for SnO_(x)-based anodes for Li storage:morphological structure tuning and phase structure design

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Rare Metals 2023年第9期42卷 2840-2867页

作者： Yu Zheng Xue-Xia Lan Xing-Yu Xiong Bin Yuan Ren-Zong Hu School of Materials Science and Engineering Guangdong Provincial Key Laboratory of Advanced Energy Storage MaterialsSouth China University of TechnologyGuangzhou510640China

Fascinating with high specific capacity and moderate lithiation potential,SnO_(x)-based materials have been intensively investigated as one of the most promising anodes for lithium-ion batteries.However,due to poor cycling stability,sluggish reaction kinetics,and limited electrochemical reaction reversibility,the development of SnO_(x)-based anodes has been hindered.And the current preparation and modification routes for SnO_(x)-based anodes lack direct and specific illustration.Herein,modification routes for SnO_(x)-based anodes have been emphasized.Firstly,to provide more direct instructions,the tuning routes of morphological structure for SnO_(x)-based electrodes(including slurry-based and self-supported)have been thoroughly discussed from the preparation perspective.Secondly,according to the properties of SnO_(x)-based anodes,the phase structure design ideas have also been properly classified and organized for addressing chemical reaction kinetics or thermodynamic issues.Finally,for future-oriented studies,new insights into the development and commercialization prospects of SnO_(x)-based anodes are also provided.This review,with comprehensive information on SnO_(x)-based anodes,aims to bring more specific guidance and valuable inspiration for peer researchers who are promoting the application of SnO_(x)-based materials for energy conversion and storage devices.

关键词： Lithium-ion battery(LIB) SnO_(x)-based anodes reaction kinetics Morphological structure tuning Phase structure design