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decomposition mechanisms of nuclear-grade cationic exchange resin by advanced oxidation processes:Statistical molecular fragmentation model and DFT calculations

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Journal of Environmental Sciences 2024年第1期135卷 433-448页

作者： Xiang Meng Pierre Désesquelles Lejin Xu Department of Nuclear Engineering and Technology School of Energy and Power EngineeringHuazhong University of Science&TechnologyWuhan 430074China CNRS Laboratoire de Physique des Gaz et des PlasmasUniversitéParis-SaclayOrsay 91405France State Key Laboratory of Coal Combustion School of Energy and Power EngineeringHuazhong University of Science and TechnologyWuhan 430074China

The treatment and disposal of radioactive waste are presently facing great challenges.Spent ion exchange resins have become a focus of attention due to their high production and serious environmental risks.In this paper,a simplified model of cationic exchange resin is proposed,and the degradation processes of cationic resin monomer initiated by hydroxyl radicals(·OH)are clarified by combining statistical molecular fragmentation(SMF)model and density functional theory(DFT)calculations.The prediction of active sites indicates that the S-O bonds and the C-S bond of the sulfonic group are more likely to react during the degradation.The meta-position of the sulfonic group on the benzene ring is the most active site,and the benzene ring without the sulfonic group has a certain reactivity.The C11-C14 and C17-C20 bonds,on the carbon skeleton,are the most easily broken.It is also found that dihydroxy addition and elimination reactions play a major role in the process of desulfonation,carbon skeleton cleavage and benzene ring separation.The decomposition mechanisms found through the combination of physical models and chemical calculations,provide theoretical guidance for the treatment of complex polycyclic aromatic hydrocarbons.

关键词： Cationic exchange resin Statistical molecular fragmentation model Density functional theory Hydroxyl radical decomposition mechanism

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Combination of Nitrogen-Rich Skeleton and Coordination Group:Synthesis of a High-Energy Primary Explosive Based on 1H-Tetrazole-5-Carbohydrazide

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Defence Technology（防务技术） 2024年第1期31卷 271-277页

作者： Tingwei Wang Zujia Lu Shu Bu Baolong Kuang Lu Zhang Zhenxin Yi Kun Wang Shunguan Zhu Jianguo Zhang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China School of Chemical Engineering Nanjing University of Science and Technology200 Xiaolingwei StreetXuanwuNanjing 210094China Department of Chemistry Laboratory of Structure and Functional Regulation of Hybrid MaterialsAnhui UniversityMinistry of EducationHefei 230601China

The high energy coordination compounds Cu(TZCA)_(2)(ClO_(4))_(2)(ECCs-1) was prepared by 1H-tetrazole-5-carbohydrazide(TZCA) with a high energy skeleton and a strong coordination ability group.At the same time,the reaction activity of the ligand was explored,and the single crystal structure of it and intermediate were obtained.The structures of all substances were characterized by IR and EA.And the structure and composition of ECCs-1 are confirmed by ESP,AC,SEM and ICP-OES.Physical and chemical properties tests show that ECCs-1 has an acceptable thermal stability(T_(d)=177℃) and extremely sensitive mechanical stimulation(IS=1 J,FS=5 N).The comprehensive performance test results show that ECCs-1 has excellent initiation ability.In addition,the decomposition mechanism of ECCs-1 is explored from two aspects of experiment and theoretical calculation.

关键词： 1H-tetrazole-5-carbohydrazide Primary explosive decomposition mechanism Coordination polymers Laser

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Non-isothermal decomposition mechanism and Kinetics of LiClO_4 in Nitrogen

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Chemical Research in Chinese Universities 2010年第2期26卷 300-303页

作者： DIAKITE Kahirou College of Chemistry and Molecular Sciences Wuhan University

The non-isothermal decomposition kinetics of LiClO4 in flow N2 atmosphere was studied. TG-DTA curves show that the decomposition proceeded through two well-defined steps below 900℃, and the mass loss was in agreement with the theoretical value. XRD profile demonstrates that the product of the thermal decomposition at 500℃ is LiCI. For the decomposition kinetics study, the activation energies calculated with the Friedman method were considered as the initial values for non-linear regression and were used for verifying the correctness of the fired models. The decomposition process was fitted by a two-step consecutive reaction： extended Prout-Tompkins equation[Bna, f（α） is （1-α）^nα^α] followed by a lth order reaction（F1）. The activation energies were （215.6±0.2） and （251.6±3.6） kJ/mol, respectively. The exponentials n and a for Bna reaction were （0.25±0.05） and （0.795±0.005）, respectively. The reaction types and activation energies were in agreement with those obtained from the isothermal method, but the exponentials were optimized for better firing and prediction.

关键词： LiClO4 decomposition mechanism Non-isothermal kinetics Non-linear regression

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mechanism of methanol decomposition on the Pd/WC(0001) surface unveiled by first-principles calculations

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Frontiers of Chemical Science and Engineering 2020年第6期14卷 1052-1064页

作者： Jinhua Zhang Yuanbin She College of Chemical Engineering Zhejiang University of TechnologyHangzhou 310014China School of Materials and Environmental Engineering Chizhou UniversityChizhou 247000China

In this study,the decomposition of methanol into the CO and H species on the Pd/tungsten carbide(WC)(0001)surface is systematically investigated using periodic density functional theory(DFT)calculations.The possible reaction pathways and intermediates are determined.The results reveal that saturated molecules,i.e.,methanol and formaldehyde,adsorb weakly on the Pd/WC(0001)surface.Both CO and H prefer three-fold sites,with adsorption energies of-1.51 and-2.67 eV,respectively.On the other hand,CH30 stably binds at three-fold and bridge sites,with an adsorption energy of-2.58 eV.However,most of the other intermediates tend to adsorb to the surface with the carbon and oxygen atoms in their sp3 and hydroxyl-like configurations,respectively.Hence,the Catom of CH2OH preferentially attaches to the top sites,CHOH and CH2O adsorb at the bridge sites,while COH and CHO occupy the three-fold sites.The DFT calculations indicate that the rupture of the initial C-H bond promotes the decomposition of CH3OH and CH2OH,whereas in the case of CHOH,O-H bond scission is favored over the C-H bond rupture.Thus,the most probable methanol decomposition pathway on the Pd/WC(0001)surface is CH3OH→ CH2OH→trans-CUOH→CHO→CO.The present study demonstrates that the synergistic effect of WC(as carrier)and Pd(as catalyst)alters the CH3OH decomposition pathway and reduces the noble metal utilization.

关键词： density functional theory methanol direct methanol fuel cells WC(0001)-supported Pd monolayer decomposition mechanism

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Microstructures and electrochemical behaviors of casting magnesium alloys with enhanced compression strengths and decomposition rates

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Journal of Magnesium and Alloys 2023年第4期11卷 1213-1223页

作者： Xuewu Li Qingyuan Yu Xi Chen Qiaoxin Zhang State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China School of Mechanical Engineering Xi’an University of Science and Technology58 Yanta RoadXi’an 710054China School of Mechanical and Electronic Engineering Wuhan University of Technology122 Luoshi RoadWuhan 430070China

New-type magnesium alloy with prominent solubility and mechanical property lays foundation for preparing fracturing part in petroleum extraction.Herein,Mg-xZn-Zr-SiC alloy is prepared with casting strategy.Electrochemical and compression tests are conducted to assess the feasibility as decomposable material.Morphology,composition,phase and distribution are characterized to investigate decomposition mechanism.Results indicate that floccule,substrate component and reticulate secondary phase are formed on as-prepared surface.Sample also acts out enhanced compression strength to maintain pressure and guarantee stability in dissolution process.Furthermore,as decomposition time and zinc content increase,couple corrosion intensifies,resulting in gradually enhanced decomposition rate.Rapid sample decomposition is mainly due to basal anode dissolution,micro particle exfoliation and poor decomposition resistance of corroding product.Such work shows profound significance in preparing new-type accessible alloy to ensure rapid dissolution of fracturing part and guarantee stable compression strength in oil-gas reservoir exploitation.

关键词： Magnesium alloy Corrosion dissolution Compression strength Electrochemical test decomposition mechanism

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Experimental and Theoretical Studies of C_(3)F_(7)CN/CO_(2) Mixture decomposition Under Overheating Fault

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CSEE Journal of Power and Energy Systems 2022年第3期8卷 941-951页

作者： Mingyue Zhao Dong Han Weikang Zhao Zhenrui Zhou Guoqiang Zhang Institute of Electrical Engineering Chinese Academy of Sciencesand University of Chinese Academy of SciencesBeijing 100190China

Heptafluoroisobutyrontrile(C_(3)F_(7)CN)performs well in dielectric properties and environmental protection,which has the potential to replace SF6 gas.The decomposition characteristics of C_(3)F_(7)CN mixture under fault conditions directly affect the possibility of its replacement for SF6 gas.However,the number of studies on the decomposition characteristics of C_(3)F_(7)CN mixture under overheating fault is less.In this paper,the decomposition characteristics of C_(3)F_(7)CN/CO_(2) mixture under an overheating fault are studied by gas chromatography-mass spectrometry(GC/MS)and quantum chemical calculations.Byproducts CO,C_(3)F_(6) and HF are detected at 200℃.At 550℃,the C_(3)F_(7)CN molecule begins to decompose and produces CHF_(3),C_(2)F_(4),CF_(3)CN and CNCN.Moreover,the results of GC/MS show that the insulation medium C_(3)F_(7)CN contains an impurity,which is C3HF7(HFC-227ea).Combined with the results of GC/MS and quantum chemistry calculations,it can be concluded that the decomposition by-product C_(3)F_(6) at 200℃ mainly comes from the decomposition of C_(3)HF_(7).C_(3)HF_(7) reduces the decomposition temperature of the C_(3)F_(7)CN/CO_(2) mixture.Therefore,it is very important to improve the purity of the insulation medium C_(3)F_(7)CN.

关键词： C3F7CN decomposition mechanism environmentally-friendly gas-insulating medium GC/MS quantum chemical

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decomposition mechanism of 1-naphthol by DC water plasmas at atmospheric pressure

Decomposition mechanism of 1-naphthol by DC water plasmas at...

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第十八届全国等离子体科学技术会议

作者：倪国华 Lin Qifu Guo Qijia 江贻满 Institute of Plasma Physics Chinese Academy of Science University of Science and Technology of China

This work investigated the decomposition mechanism of high concentration 1-naphthol solution in DC water plasmas at atmospheric pressure.The experimental results showed that the concentration of 1-naphthol was reduced from 5 g/L down to 0.722 g/L at arc current of 8 A with the energy efficiency of 8.99×10-10 mol/J.The decomposition efficiencies of 1-naphthol,chemical oxygen demand(COD) and total organic carbon(TOC) were increased with the increase in arc current(6 A-8 A) at same arc voltage,while the initial concentration of 1-naphthol had a negative correlation with them.The gaseous products were determined using the combination of gas chromatograph equipped(GC) with a thermal conductivity detector(TCD).The major gaseous effluents were H2,CO,CH4 and CO2,which the content of syngas was over 50%.Furthermore,the CO selectivity had a negative correlation with arc current.The intermediate products were identified by gas chromatography/mass spectroscopy(GC/MS) analysis technique.It was found that the gaseous intermediate byproducts of 1-naphthol solution were ethanol,tert-butanol,acetic acid,benzene,and so on.Further,acetic acid,acetaldehyde and oxalic acid were observed in the liquid effluents.A possible decomposition mechanism could be proposed.

关键词： Water plasma 1-naphthol decomposition mechanism

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ON THE decomposition OF ALITE IN PORTLAND CEMENT CLINKER

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Journal of Wuhan University of Technology(Materials Science) 1998年第2期13卷 26-31页

作者：刘顺妮 Wuhan University of Technology China Coll. of Mat. Science and Technology Wuhan Univ. of Tech. Wuhan 430070 China

The decomposition speed and mechanism of alite in Portland cement clinker are studied by means of optical microscopy, EPMA, XRD and chemical analysis. The results show that alite in portland cement clinker decomposes at the maximum speed when the temperature is at 1025 to approximately 1175 degree C. It takes about 40 hours for the alite in clinker burnt in the rotary kiln to completely decompose at 1175 degree C, and about 68 hours for the alite burnt in RSP-kiln. The presence of CaF//2 or CaSO//4 greatly affects the decomposition speed of alite. The former resists alite to decompose but the latter accelerates it and enables alite to decompose completely within 6 hours or less. (Author abstract) 3 Refs.

关键词： decomposition of alite cement clinker decomposition mechanism

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Enhancing performance of tin-based perovskite solar cells via fused-ring electron acceptor

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eScience 2023年第3期3卷 89-95页

作者： Chengbo Wang Yiting Jiang Hanyu Xu Nanlong Zheng Guangsheng Bai Yanxin Zha Hao Qi Zuqiang Bian Xiaowei Zhan Zhiwei Liu Beijing National Laboratory for Molecular Sciences State Key Laboratory of Rare Earth Materials Chemistry and ApplicationsCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871PR China Key Laboratory of Polymer Chemistry and Physics of Ministry of Education School of Materials Science and EngineeringPeking UniversityBeijing100871PR China

The performance of tin-based perovskite solar cells has been substantially hampered by voltage loss caused by energy level mismatch,charge recombination,energetic disorder,and other issues.Here,a fused-ring electron acceptor based on indacenodithiophene(IDIC)was for the first time introduced as a transition layer between a tin-based perovskite layer and a C 60 electron transport layer,leading to better matched energy levels in the device.In addition,coordination interactions between IDIC and perovskite improved the latter's crystallinity.The introduction of IDIC raised the power conversion efficiency from 8.98%to 11.5%and improved the device's stability.The decomposition mechanism of tin-based perovskite was also revealed by detecting the optical properties of perovskite microdomains through innovative integration of confocal laser scanning microscopy and photoluminescence spectroscopy.

关键词： Perovskite solar cell Tin Fused-ring electron acceptor decomposition mechanism

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A novel double dielectric barrier discharge reactor with high field emission and secondary electron emission for toluene abatement

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Plasma Science and Technology 2022年第1期24卷 118-128页

作者：李世杰于欣党小庆王鹏勇孟祥康郑华春 School of Environment&Municipal Engineering Xi'an University of Architecture&TechnologyXi'an 710055People’s Republic of China Shaanxi Key Laboratory of Environmental Engineering Xi'an University of Architecture&TechnologyXi’an 710055People’s Republic of China Key Laboratory of Northwest Water Resources Environment and EcologyMinistry of EducationXi'an University of Architecture and TechnologyXi’an 710055People’s Republic of China

Dielectric barrier discharge(DBD)has been extensively investigated in the fields of environment and energy,whereas its practical implementation is still limited due to its unsatisfactory energy efficiency.In order to improve the energy efficiency of DBD,a novel double dielectric barrier discharge(NDDBD)reactor with high field emission and secondary electron emission was developed and compared with traditional DDBD(TDDBD)configuration.Firstly,the discharge characteristics of the two DDBD reactors were analyzed.Compared to TDDBD,the NDDBD reactor exhibited much stronger discharge intensity,higher transferred charge,dissipated power and gas temperature due to the effective utilization of cathode field emission and secondary electron emission.Subsequently,toluene abatement performance of the two reactors was evaluated.The toluene decomposition efficiency and mineralization rate of NDDBD were much higher than that of TDDBD,which were 86.44%-100%versus 28.17%-80.48%and 17.16%-43.42%versus 7.17%-16.44%at 2.17-15.12 W and 1.24-4.90 W respectively.NDDBD also exhibited higher energy yield than TDDBD,whereas the overall energy constant k_(overall)of the two reactors were similar.Finally,plausible toluene decomposition pathway in TDDBD and NDDBD was suggested based on organic intermediates that generated from toluene degradation.The finding of this study is expected to provide reference for the design and optimization of DBD reactor for volatile organic compounds control and other applications.

关键词： toluene removal double dielectric barrier discharge field emission secondary electron emission decomposition mechanism

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