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A New Method for the Aging Evaluation of Oil-Paper Insulation Using η-Butanol and Methanol

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 717-726页

作者： Jianyi Wang Yuanxiang Zhou Jun Liu Zhaowei Wang Song Bai Jiayu Lu Department of High Voltage China Electric Power Research InstituteBeijing 100192China State Key Laboratory of Power Grid Environmental Protection Beijing 100192China Electrical Engineering Department Tsinghua UniversityBeijing 100084China Solar Storage Division of State Key Lab of Power System and Generation Equipment School of Electrical EngineeringXinjiang UniversityUrumqi 830047China State Grid Wuwei Electric Power Supply Company Wuwei 733000China

To improve the accuracy and efficiency of the aging life prediction and assessment of transformer oil-paper insulation,and to make up for the deficiencies of traditional characterizers,such as 2-furfural,carbon monoxide,and carbon dioxide,a method for the simultaneous determination of Methanol,ethanol,n−propanol,and η-butanol in oil with a single injection is established by headspace-gas chromatography-mass spectrometry.The measured results show that the determination limits of the four alcohol characterizers can be controlled to 10μg/kg level.Based on this method,the change patterns of the above four alcohols with thermal aging time and degree of polymerization are obtained through thermal aging experimental research.Ethanol,η-propanol,and η-butanol in oil indicate nearly linear correlations with thermal aging time and degree of polymerization,similar to that of Methanol.By analyzing 52 sets of measured data of 500 kV EHV transformers in operation,η-butanol is found to have excellent performance,and a new method to evaluate the aging state of oil-paper insulation employing η-butanol and Methanol is proposed along with the aging attention value model.The measured data of 500 kV EHV transformers in operation indicate that the combination of η-butanol and Methanol as the preferred characterizers can effectively compensate for the shortcoming of traditional characterizers in the early stages of aging,and the feasibility of the method is verified.Two possible pathways for the generation of η-butanol by cellulose cleavage during the aging of oil-paper are proposed from the chemical structure of cellulose.

关键词： Aging characterization determination method Methanol η-butanol oil-paper insulation 500 kV transformers

Effect of reduction pretreatment on the structure and catalytic performance of Ir-In_(2)O_(3)catalysts for CO_(2) hydrogenation to Methanol

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Journal of Environmental Sciences 2024年第6期140卷 2-11页

作者： Changyu Ding Feifei Yang Xue Ye Chongya Yang Xiaoyan Liu Yuanlong Tan Zheng Shen Hongmin Duan Xiong Su Yanqiang Huang CAS Key Laboratory of Science and Technology on Applied Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China University of Chinese Academy of Sciences Beijing 100049China

In_(2)O_(3)has been found a promising application in CO_(2)hydrogenation to Methanol,which is beneficial to the utilization of CO_(2).The oxygen vacancy(O_(v))site is identified as the catalytic active center of this reaction.However,there remains a great challenge to understand the relations between the state of oxygen species in In_(2)O_(3)and the catalytic performance for CO_(2)hydrogenation to Methanol.In the present work,we compare the properties of multiple In_(2)O_(3)and Ir-promoted In_(2)O_(3)(Ir-In_(2)O_(3))catalysts with different Ir loadings and after being pretreated under different reduction temperatures.The CO_(2)conversion rate of Ir-In_(2)O_(3)is more promoted than that of pure In_(2)O_(3).With only a small amount of Ir loading,the highly dispersed Ir species on In_(2)O_(3)increase the concentration of O_(v)sites and enhance the activity.By finely tuning the catalyst structure,Ir-In_(2)O_(3)with an Ir loading of 0.16 wt.%and pre-reduction treatment under 300℃exhibits the highest Methanol yield of 146 mgCH_(3)OH/(gcat·hr).Characterizations of Raman,electron paramagnetic resonance,X-ray photoelectron spectroscopy,CO_(2)-temperature programmed desorption and CO_(2)-pulse adsorption for the catalysts confirm that more O_(v)sites can be generated under higher reduction temperature,which will induce a facile CO_(2)adsorption and desorption cycle.Higher performance for Methanol production requires an adequate dynamic balance among the surface oxygen atoms and vacancies,which guides us to find more suitable conditions for catalyst pretreatment and reaction.

关键词： Carbon dioxide Hydrogenation Methanol In_(2)O_(3) Fixed-bed Reduction temperature

Zeolite-encaged mononuclear copper centers catalyze CO2 selective hydrogenation to Methanol

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National Science Review 2023年第7期10卷 134-141页

作者： Yuchao Chai Bin Qin Bonan Li Weili Dai Guangjun Wu Naijia Guan Landong Li Key Laboratory of Advanced Energy Materials Chemistry of Ministry of Education College of Chemistry Nankai University CAS Key Laboratory of Science and Technology on Applied Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences School of Materials Science and Engineering Nankai University

The selective hydrogenation of CO2to Methanol by renewable hydrogen source represents an attractive route for CO2recycling and is carbon neutral.Stable catalysts with high activity and Methanol selectivity are being vigorously pursued,and current debates on the active site and reaction pathway need to be clarified.Here,we report a design of faujasite-encaged mononuclear Cu centers,namely Cu@FAU,for this challenging reaction.Stable Methanol space-time-yield(STY) of 12.8 mmol gcat-1h-1and Methanol selectivity of 89.5% are simultaneously achieved at a relatively low reaction temperature of 513 K,making Cu@FAU a potential Methanol synthesis catalyst from CO2hydrogenation.With zeolite-encaged mononuclear Cu centers as the destined active sites,the unique reaction pathway of stepwise CO2hydrogenation over Cu@FAU is illustrated.This work provides a clear example of catalytic reaction with explicit structure-activity relationship and highlights the power of zeolite catalysis in complex chemical transformations.

关键词： CO2 hydrogenation zeolite Methanol catalysis mononuclear copper

Engineering the native methylotrophs for the bioconversion of Methanol to value-added chemicals:current status and future perspectives

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Green Chemical Engineering 2023年第2期4卷 199-211页

作者： Jing Wang Ruirui Qin Yuanke Guo Chen Ma Xin Wang Kequan Chen Pingkai Ouyang State Key Laboratory of Materials-Oriented Chemical Engineering College of Biotechnology and Pharmaceutical EngineeringNanjing Tech UniversityNanjing211816China

Methanol is becoming an attractive fermentation feedstock for large-scale bioproduction of chemicals,due to its natural abundance and mature production technology.Native methylotrophs,which can utilize Methanol as the only source of carbon and energy,are ideal hosts for Methanol bioconversion due to their high Methanol utili-zation rate and have been extensively employed in the production of value-added chemicals from Methanol.Here,we review the natural Methanol utilization pathways in native methylotrophs,describing the available synthetic biology tools developed for engineering native methylotrophs,and discuss the strategies for improving their Methanol utilization efficiency.Finally,the representative examples of engineering the native methylotrophs to produce value-added products from Methanol are summarized.Furthermore,we also discuss the major challenges and possible solutions for the application of native methylotrophs in Methanol-based biomanufacturing.

关键词： Native methylotrophs Methanol Biomanufacturing Value-added chemicals

Interface engineering of ZnSnO_(3)-based heterojunctions for room-temperature Methanol monitoring

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Rare Metals 2023年第12期42卷 4153-4166页

作者： Jin-Yong Xu Kai-Chun Xu Xiao-Xi He Han-Lin Liao Marc Debliquy Qiao-Quan Liu Chao Zhang College of Mechanical Engineering Yangzhou UniversityYangzhou 225127China ICB UMR 6303 CNRSUniv.Bourgogne Franche-ComteUTBMBelfort 90010France Service de Science des Matériaux Faculte PolytechniqueUniversitéde MonsMons 7000Belgium College of Agriculture Yangzhou UniversityYangzhou 225009China

Detecting Methanol is of great importance in the organic synthesis industry.Herein,the effective utilization of ZnSnO_(3)-based microstructures for room-temperature Methanol monitoring was realized through a template-free approach.ZnSnO_(3)-based heterojunctions with different structures and morphologies were successfully synthesized via regulating the molar ratio of Zn2+and Sn4+sources.And room-temperature sensing properties towards Methanol were investigated.Among them,ZnO/ZnSnO_(3) hollow microcubes exhibited an outstanding sensing performance including a high sensitivity(10.16)and a response/recovery time(14/75 s)and a limit of detection(490×10^(-9))towards 5×10^(-6)Methanol.Additionally,the synergistic effects of hollow structure with larger specific surface areas(42.277 m^(2)·g^(-1)),the construction of n-n heterojunctions formed at ZnSnO_(3) and ZnO interfaces,the high percentage of dissociative and chemisorbed oxygen are the main causes of the elevated sensing characteristics.Besides,the practical experiment demonstrated that ZnO/ZnSnO_(3) was capable of on-field monitoring Methanol in the chemical reaction utilizing H_(2) and CO_(2) as raw materials.Moreover,with the help of density functional theory calculations,the enhanced sensing properties of ZnO/ZnSnO_(3) are due to the special tuning effects of Zn ionic sites on Methanol adsorption.

关键词： ZnSnO_(3) Heterojunctions Methanol Gas sensor Density functional theory calculations

Self-Assembly of Silver Clusters into One-and Two-Dimensional Structures and Highly Selective Methanol Sensing

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Research 2023年第1期2022卷 565-571页

作者： Zhaoxian Qin Zhiwen Li Sachil Sharma Yongwu Peng Rongchao Jin Gao Li State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China Department of Chemistry Carnegie Mellon UniversityPittsburghPA 15213USA College of Materials Science and Engineering and College of Chemical Engineering Zhejiang University of TechnologyHangzhou 310014China University of Chinese Academy of Sciences 100049 BeijingChina

The development of new materials for the design of sensitive and responsive sensors has become a crucial research direction.Here,two silver cluster-based polymers(Ag-CBPs),including one-dimensional[Ag_(22)(L1)_(8)(CF_(3)CO_(2))_(14)](CH_(3)OH)_(2))n chain and two-dimensional[Ag_(12)(L2)_(2)(CO_(2)CF_(3))_(14)(H_(2)O)_(4)(AgCO_(2)CF_(3))_(4)](HNEt_(3))_(2))_(n) film,are designed and used to simulate the human nose,an elegant sensor to smells,to distinguish organic solvents.We study the relationship between the atomic structures of Ag-CBPs determined by x-ray diffraction and the electrical properties in the presence of organic solvents(e.g.,Methanol and ethanol).The ligands,cations,and the ligated solvent molecules not only play an important role in the self-assembly process of Ag-CBP materials but also determine their physiochemical properties such as the sensing functionality.

关键词： silver Highly Methanol

Dual active sites over Cu-ZnO-ZrO_(2) catalysts for carbon dioxide hydrogenation to Methanol

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Journal of Environmental Sciences 2023年第9期131卷 162-172页

作者： Xiucheng Sun Yifei Jin Zaizhe Cheng Guojun Lan Xiaolong Wang Yiyang Qiu Yanjiang Wang Huazhang Liu Ying Li Institute of Industrial Catalysis Zhejiang University of TechnologyHangzhou 310014China

CO_(2) hydrogenation to Methanol is a significant approach to tackle the problem of global warming and simultaneously meet the demand for the portable fuel.Cu-ZnO catalysts with various kinds of promoters have received wide attention.However,the role of promoter and the form of active sites in CO_(2) hydrogenation are still in debate.Here,various molar ratios of ZrO_(2) were added into the Cu-ZnO catalysts to tune the distributions of Cu^(0) and Cu+species.A volcano-like trend between the ratio of Cu+/(Cu++Cu^(0))and the amount of ZrO_(2) is presented,among which the CuZn10Zr(the molar ratio of ZrO_(2) is 10%)catalyst reaches the highest value.Correspondingly,the maximum value of space-time yield to Methanol with 0.65 gMeOH/(gcat·hr)is obtained on CuZn10Zr at reaction conditions of 220°C and 3 MPa.Detailed characterizations demonstrate that dual active sites are proposed during CO_(2) hydrogenation over CuZn10Zr catalyst.The exposed Cu^(0) takes participate in the activation of H_(2),while on the Cu^(+) species,the intermediate of formate from the co-adsorption of CO_(2) and H_(2) prefers to be further hydrogenated to CH_(3)OH than decomposing into the by-product of CO,yielding a high selectivity of Methanol.

关键词： Cu-ZnO-ZrO_(2) CO_(2)hydrogenation Methanol Dual active sites Formate

Tandem photo-oxidation of methane to Methanol at room temperature and pressure over Pt/TiO_(2)

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Nano Research 2023年第12期16卷 12942-12948页

作者： Yingxue Sun Chunling Bo Zhijie Cheng Xinyi Zhang Jianjun Liu Lingyu Piao State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China National Center for Nanoscience and Technology Beijing 100190China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Marine Chemistry Theory and Technology(Ministry of Education) College of Chemistry&Chemical EngineeringOcean University of ChinaQingdao 266100China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

In the process of methane(CH_(4))oxidation to Methanol(CH3OH),CH3OH is more easily oxidized than CH_(4),resulting in inevitable peroxide phenomenon.In this work,we innovatively proposed a tandem reaction pathway to obtain a photocatalytic oxidation process of CH_(4) with high activity and selectivity.This work confirms that the methyl hydrogen peroxide(CH3OOH),the first product of CH_(4) oxidation by H_(2)O_(2),is then completely reduced to CH3OH in an electron-rich environment.Under irradiation,H_(2)O_(2) was excited into hydroxyl radicals(·OH)and hydroperoxyl radicals(·OOH)on brookite TiO_(2) photocatalyst.The·OH oxidized CH_(4) to form methyl radicals(·CH3),which then reacted with·OOH to form CH3OOH.CH3OOH gained electrons on Pt nanoparticles(NPs)and was reduced to CH3OH.At this point,low concentration of·OH was difficult to further oxidize CH3OH,so that it can exist stably.Under the conditions of room temperature(25°C)and atmospheric pressure,the productivity of CH3OH was 883μmol/(g·h),which was 4 times more than the reported photocatalytic CH_(4) oxidation system with the same reaction conditions,and the selectivity was 100%in liquid products(98.77%for all products).The photocatalyst showed excellent stability and maintained>85%product activity after 9 catalytic cycles.This work contributed to the development of highly efficient and selective CH_(4) photooxidation system under mild conditions.

关键词： photocatalytic oxidation of methane Methanol tandem reaction TiO_(2)

Using Methanol as a Formaldehyde Surrogate for Sustainable Synthesis of N-Heterocycles via Manganese-Catalyzed Dehydrogenative Cyclization

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Chinese Journal of Chemistry 2022年第10期40卷 1137-1143页

作者： Zhihui Shao Shanshan Yuan Yibiao Li Qiang Liu Center of Basic Molecular Science(CBMS) Department of ChemistryTsinghua UniversityBeijing 100084China Flavors and Fragrance Engineering&Technology Research Center of Henan Province College of Tobacco ScienceHenan Agricultural UniversityZhengzhouHenan 450002China School of Biotechnology and Health Sciences Wuyi UniversityJiangmenGuangdong 529090China

The development of an efficient and sustainable synthetic route for formaldehyde production from renewable feedstock,especially in combination with a subsequent transformation to straightforwardly construct valuable chemicals,is highly desirable.Herein,we report a novel manganese-catalyzed dehydrogenative cyclization of Methanol as a formaldehyde surrogate with a variety of dinucleophiles for facile synthesis of N-heterocycles.The in situ generated formaldehyde via catalytic Methanol dehydrogenation can be selectively trapped by diverse dinucleophiles to avoid several possible side reactions.The utilty of this transformation is further highlighted by its successful appliation to the synthesis of 13C-labeled N-heterocycles using 13CH_(3)OH as a readily accessible 13C-isotope reagent.

关键词： Methanol Dehydrogenation Formaldehyde surrogate Manganese catalysis N-heterocycles