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Sulfur doped iron-nitrogen-hard carbon nanosheets as efficient and robust noble metal-free catalysts for oxygen reduction reaction in PEMFC
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作者 Bin Liu Jiawang Li +6 位作者 Bowen Yan Qi Wei Xingyu Wen Huarui Xie Huan He Pei Kang Shen Zhi Qun Tian 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第2期422-433,I0010,共13页
Transition metal-nitrogen-carbon(M-N-C)as a promising substitute for the conventional noble metalbased catalyst still suffers from low activity and durability for oxygen reduction reaction(ORR)in proton exchange membr... Transition metal-nitrogen-carbon(M-N-C)as a promising substitute for the conventional noble metalbased catalyst still suffers from low activity and durability for oxygen reduction reaction(ORR)in proton exchange membrane fuel cells(PEMFCs).To tackle the issue,herein,a new type of sulfur-doped ironnitrogen-hard carbon(S-Fe-N-HC)nanosheets with high activity and durability in acid media were developed by using a newly synthesized precursor of amide-based polymer with Fe ions based on copolymerizing two monomers of 2,5-thiophene dicarboxylic acid(TDA)as S source and 1,8-diaminonaphthalene(DAN)as N source via an amination reaction.The as-synthesized S-Fe-N-HC features highly dispersed atomic Fe Nxmoieties embedded into rich thiophene-S doped hard carbon nanosheets filled with highly twisted graphite-like microcrystals,which is distinguished from the majority of M-N-C with soft or graphitic carbon structures.These unique characteristics endow S-Fe-N-HC with high ORR activity and outstanding durability in 0.5 M H_(2)SO_(4).Its initial half-wave potential is 0.80 V and the corresponding loss is only 21 m V after 30,000 cycles.Meanwhile,its practical PEMFC performance is a maximum power output of 628.0 mW cm^(-2)and a slight power density loss is 83.0 m W cm^(-2)after 200-cycle practical operation.Additionally,theoretical calculation shows that the activity of Fe Nxmoieties on ORR can be further enhanced by sulfur doping at meta-site near FeN_(4)C.These results evidently demonstrate that the dual effect of hard carbon substrate and S doping derived from the precursor platform of amid-polymers can effectively enhance the activity and durability of Fe-N-C catalysts,providing a new guidance for developing advanced M-N-C catalysts for ORR. 展开更多
关键词 Transition metal-nitrogen-carbon Oxygen reduction reaction Hard carbon Amide based polymer reaction Proton exchange membrane cells
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Boosted Electrocatalytic Glucose Oxidation Reaction on Noble-Metal-Free MoO_(3)-Decorated Carbon Nanotubes
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作者 Yu-Long Men Ning Dou +3 位作者 Yiyi Zhao Yan Huang Lei Zhang Peng Liu 《Transactions of Tianjin University》 EI CAS 2024年第1期63-73,共11页
Electrocatalytic glucose oxidation reaction(GOR)has attracted much attention owing to its crucial role in biofuel cell fabrication.Herein,we load MoO_(3)nanoparticles on carbon nanotubes(CNTs)and use a discharge proce... Electrocatalytic glucose oxidation reaction(GOR)has attracted much attention owing to its crucial role in biofuel cell fabrication.Herein,we load MoO_(3)nanoparticles on carbon nanotubes(CNTs)and use a discharge process to prepare a noblemetal-free MC-60 catalyst containing MoO_(3),Mo_(2)C,and a Mo_(2)C–MoO_(3)interface.In the GOR,MC-60 shows activity as high as 745μA/(mmol/L cm^(2)),considerably higher than those of the Pt/CNT(270μA/(mmol/L cm^(2)))and Au/CNT catalysts(110μA/(mmol/L cm^(2))).In the GOR,the response minimum on MC-60 is as low as 8μmol/L,with a steady-state response time of only 3 s.Moreover,MC-60 has superior stability and anti-interference ability to impurities in the GOR.The better performance of MC-60 in the GOR is attributed to the abundant Mo sites bonding to C and O atoms at the MoO_(3)–Mo_(2)C interface.These Mo sites create active sites for promoting glucose adsorption and oxidation,enhancing MC-60 performance in the GOR.Thus,these results help to fabricate more effi cient noble-metal-free catalysts for the fabrication of glucose-based biofuel cells. 展开更多
关键词 Interface eff ect ELECTROCATALYSIS Molybdenum oxide GLUCOSE Oxidation reaction
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Recent Advances in Mechanistic Understanding of Metal-Free Carbon Thermocatalysis and Electrocatalysis with Model Molecules
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作者 Wei Guo Linhui Yu +2 位作者 Ling Tang Yan Wan Yangming Lin 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第7期74-97,共24页
Metal-free carbon,as the most representative heterogeneous metal-free catalysts,have received considerable interests in electro-and thermo-catalytic reac-tions due to their impressive performance and sustainability.Ov... Metal-free carbon,as the most representative heterogeneous metal-free catalysts,have received considerable interests in electro-and thermo-catalytic reac-tions due to their impressive performance and sustainability.Over the past decade,well-designed carbon catalysts with tunable structures and heteroatom groups coupled with various characterization techniques have proposed numerous reaction mechanisms.However,active sites,key intermediate species,precise structure-activity relationships and dynamic evolution processes of carbon catalysts are still rife with controversies due to the monotony and limitation of used experimental methods.In this Review,we sum-marize the extensive efforts on model catalysts since the 2000s,particularly in the past decade,to overcome the influences of material and structure limitations in metal-free carbon catalysis.Using both nanomolecule model and bulk model,the real contribution of each alien species,defect and edge configuration to a series of fundamentally important reactions,such as thermocatalytic reactions,electrocatalytic reactions,were systematically studied.Combined with in situ techniques,isotope labeling and size control,the detailed reaction mechanisms,the precise 2D structure-activity relationships and the rate-determining steps were revealed at a molecular level.Furthermore,the outlook of model carbon catalysis has also been proposed in this work. 展开更多
关键词 metal-free carbon catalysts Model catalyst ELECTROCATALYSIS Active site reaction mechanisms
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Recent advances and perspectives of zinc metal-free anodes for zinc ion batteries
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作者 Jiabing Miao Yingxiao Du +5 位作者 Ruotong Li Zekun Zhang Ningning Zhao Lei Dai Ling Wang Zhangxing He 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CSCD 2024年第1期33-47,共15页
Zinc-ion batteries(ZIBs) are recognized as potential energy storage devices due to their advantages of low cost, high energy density, and environmental friendliness. However, zinc anodes are subject to unavoidable zin... Zinc-ion batteries(ZIBs) are recognized as potential energy storage devices due to their advantages of low cost, high energy density, and environmental friendliness. However, zinc anodes are subject to unavoidable zinc dendrites, passivation, corrosion, and hydrogen evolution reactions during the charging and discharging of batteries, becoming obstacles to the practical application of ZIBs. Appropriate zinc metal-free anodes provide a higher working potential than metallic zinc anodes, effectively solving the problems of zinc dendrites, hydrogen evolution, and side reactions during the operation of metallic zinc anodes. The improvement in the safety and cycle life of batteries creates conditions for further commercialization of ZIBs. Therefore, this work systematically introduces the research progress of zinc metal-free anodes in “rocking chair” ZIBs. Zinc metal-free anodes are mainly discussed in four categories: transition metal oxides,transition metal sulfides, MXene(two dimensional transition metal carbide) composites, and organic compounds, with discussions on their properties and zinc storage mechanisms. Finally, the outlook for the development of zinc metal-free anodes is proposed. This paper is expected to provide a reference for the further promotion of commercial rechargeable ZIBs. 展开更多
关键词 zinc ion batteries ANODE zinc metal-free anode recent advances PERSPECTIVES
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Noble-Metal-Free Oxygen Evolution Reaction Electrocatalysts Working at High Current Densities over 1000 mA cm^(-2):From Fundamental Understanding to Design Principles
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作者 Xian Zhang Mengtian Jin +5 位作者 Feifei Jia Jiaqi Huang Abbas Amini Shaoxian Song Hao Yi Chun Cheng 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第5期43-59,共17页
Alkaline water electrolysis provides a promising route for"green hydrogen"generation,where anodic oxygen evolution reaction(OER)plays a crucial role in coupling with cathodic hydrogen evolution reaction.To d... Alkaline water electrolysis provides a promising route for"green hydrogen"generation,where anodic oxygen evolution reaction(OER)plays a crucial role in coupling with cathodic hydrogen evolution reaction.To date,the development of highly active and durable OER catalysts based on earth-abundant elements has drawn wide attention;nevertheless,their performance under high current densities(HCDs≥1000 mA cm^(-2))has been less emphasized.This situation has seriously impeded large-scale electrolysis industrialization.In this review,in order to provide a guideline for designing high-performance OER electrocatalysts,the effects of HCD on catalytic performance involving electron transfer,mass transfer,and physical/chemical stability are summarized.Furthermore,the design principles were pointed out for obtaining efficient and robust OER electrocatalysts in light of recent progress of OER electrocatalysts working above 1000 mA cm^(-2).These include the aspects of developing self-supported catalytic electrodes,enhancing intrinsic activity,enhancing the catalyst-support interaction,engineering surface wettability,and introducing protective layer.Finally,summaries and outlooks in achieving OER at industrially relevant HCDs are proposed. 展开更多
关键词 alkaline water splitting high current density long-term stability noble-metal-free electrocatalysts oxygen evolution reaction
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Metal-Free 2D/2D van der Waals Heterojunction Based on Covalent Organic Frameworks for Highly Efficient Solar Energy Catalysis 被引量:5
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作者 Ge Yan Xiaodong Sun +5 位作者 Yu Zhang Hui Li Hongwei Huang Baohua Jia Dawei Su Tianyi Ma 《Nano-Micro Letters》 SCIE EI CAS CSCD 2023年第9期15-30,共16页
Covalent organic frameworks(COFs)have emerged as a kind of rising star materials in photocatalysis.However,their photocatalytic activities are restricted by the high photogenerated electron-hole pairs recombination ra... Covalent organic frameworks(COFs)have emerged as a kind of rising star materials in photocatalysis.However,their photocatalytic activities are restricted by the high photogenerated electron-hole pairs recombination rate.Herein,a novel metal-free 2D/2D van der Waals heterojunction,composed of a two-dimensional(2D)COF with ketoenamine linkage(TpPa-1-COF)and 2D defective hexagonal boron nitride(h-BN),is successfully constructed through in situ solvothermal method.Benefitting from the presence of VDW heterojunction,larger contact area and intimate electronic coupling can be formed between the interface of TpPa-1-COF and defective h-BN,which make contributions to promoting charge car-riers separation.The introduced defects can also endow the h-BN with porous structure,thus providing more reactive sites.Moreover,the TpPa-1-COF will undergo a structural transformation after being integrated with defective h-BN,which can enlarge the gap between the conduction band position of the h-BN and TpPa-1-COF,and suppress electron backflow,corroborated by experimental and density functional theory calculations results.Accordingly,the resulting porous h-BN/TpPa-1-COF metal-free VDW heterojunction displays out-standing solar energy catalytic activity for water splitting without co-catalysts,and the H_(2) evolution rate can reach up to 3.15 mmol g^(−1) h^(−1),which is about 67 times greater than that of pristine TpPa-1-COF,also surpassing that of state-of-the-art metal-free-based photocatalysts reported to date.In particular,it is the first work for constructing COFs-based heterojunctions with the help of h-BN,which may provide new avenue for designing highly efficient metal-free-based photocatalysts for H_(2) evolution. 展开更多
关键词 Covalent organic frameworks 2D/2D van der Waals heterojunction metal-free photocatalyst
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Metal-free carbocatalysis for electrochemical oxygen reduction reaction: Activity origin and mechanism 被引量:5
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作者 Yuhang Li Yexiang Tong Feng Peng 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2020年第9期308-321,I0010,共15页
Although scientists have conducted long-term and extensive studies on oxygen reduction reaction(ORR)catalyzed by metal-free carbon materials,they mainly have focused on the preparation and properties of various doped ... Although scientists have conducted long-term and extensive studies on oxygen reduction reaction(ORR)catalyzed by metal-free carbon materials,they mainly have focused on the preparation and properties of various doped carbon materials.There is still a lack of systematic scientific guidance on the relationship between the surface structure regulation and activity of carbon-based catalysts.In this review,some of electrochemical and computational fundamental concepts about ORR are concisely summarized.The effects of edge defect and nonmetallic doping of carbon materials on ORR behavior and mechanism have been reviewed,and activity origin identification and intermediate conversion mechanism have been discussed.The outlooks for future researches on metal-free ORR electrocatalysis are suggested. 展开更多
关键词 Carbocatalysis ELECTROCATALYSIS Oxygen reduction reaction Review metal-free doping
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Reaction视频中用户弹幕信息交互行为的情感反应生成机理研究
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作者 叶许婕 赵宇翔 +2 位作者 张妍 李金昊 Preben Hansen 《信息资源管理学报》 2024年第2期104-120,共17页
深入挖掘Reaction视频中弹幕信息交互行为的情感反应机理有助于理解用户弹幕创作背后的情感生成原因及情感变化过程。本文基于情感反应模型,利用定向内容分析法对哔哩哔哩网站中11个热门视频的弹幕信息资源、视频内容以及reactor反应情... 深入挖掘Reaction视频中弹幕信息交互行为的情感反应机理有助于理解用户弹幕创作背后的情感生成原因及情感变化过程。本文基于情感反应模型,利用定向内容分析法对哔哩哔哩网站中11个热门视频的弹幕信息资源、视频内容以及reactor反应情况展开编码研究,构建了Reaction视频中用户弹幕信息交互行为的情感反应生成机理模型。研究发现,Reaction视频弹幕信息交互行为中的情感反应生成机理总体上遵循“信息刺激-情感反应”的路径,信息刺激有时会独立唤醒情绪或特定情感态度,有时也会通过唤醒特定情感态度进而影响情绪或内化情感态度的生成。该模型有助于提升情感反应理论在计算机协助交流中的情境化探索,也将为社交媒体中用户与信息交互提供优化建议。 展开更多
关键词 reaction视频 弹幕 用户信息交互 情感反应模型 定向内容分析
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Hydrogenated Graphene as Metal-free Catalyst for Fenton-like Reaction 被引量:3
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作者 Yi Zhao Wu-feng Chen +2 位作者 Cheng-fei Yuan Zi-ye Zhu Li-feng Yan 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2012年第3期335-338,374,共5页
Carbonaceous catalysts are potential alternatives to metal catalysts. Graphene has been paid much attention for its high surface area and light weight. Here, hydrogenated graphene has been prepared by a simple gamma r... Carbonaceous catalysts are potential alternatives to metal catalysts. Graphene has been paid much attention for its high surface area and light weight. Here, hydrogenated graphene has been prepared by a simple gamma ray irradiation of graphene oxide aqueous suspension at room temperature. Transmission electron microscopic, element analysis, X-ray photoelectron spectroscopy, and UV-Vis spectrophotometer studies verified the hydrogenation of graphene. The as-prepared hydrogenated graphene can be used as a metal-free carbonaceous catalyst for the Fenton-like degradation of organic dye in water. 展开更多
关键词 GRAPHENE HYDROGENATION metal-free CATALYSIS
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Surface/interface engineering of high-efficiency noble metal-free electrocatalysts for energy-related electrochemical reactions 被引量:8
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作者 Hui Zhao Zhong-Yong Yuan 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第3期89-104,共16页
To date,much efforts have been devoted to the high-efficiency noble metal-free electrocatalysts for hydrogen-and oxygen-involving energy conversion reactions,due to their abundance,low cost and nultifunctionally.Surfa... To date,much efforts have been devoted to the high-efficiency noble metal-free electrocatalysts for hydrogen-and oxygen-involving energy conversion reactions,due to their abundance,low cost and nultifunctionally.Surface/interface engineering is found to be effective in achieving novel physicochemical properties and synergistic effects in nanomaterials for electrocatalysis.Among various engineering strategies,heteroatom-doping has been regarded as a most promising method to improve the electrocatalytic performance via the regulation of electronic structure of catalysts,and numerous works were reported on the synthesis method and mechanism investigation of heteroatom-doping electrocatalysts,though the heteroatom-doping can only provide limited active sites.Engineering of other defects such as vacancies and edge sites and construction of heterostructure have shown to open up a potential avenue for the development of noble metal-free electrocatalysts.In addition,surface functionalization can attach various molecules onto the surface of materials to easily modify their physical or chemical properties,being as a promising complement or substitute for offering materials with catalytic properties.This paper gives the insights into the diverse strategies of surface/interface engineering of the highefficiency noble metal-free electrocatalysts for energy-related electrochemical reactions.The significant advances are summarized.The unique advantages and mechanisms for specific applications are highlighted.The current challenges and outlook of this growing field are also discussed. 展开更多
关键词 Noble metal-free electrocatalysts Electrocatalysis Surface/interface engineering Metal-air battery Overall water splitting
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Pyrazine-nitrogen-rich exfoliated C4N nanosheets as efficient metal-free polymeric catalysts for oxygen reduction reaction 被引量:1
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作者 Yuan Li Chunshao Mo +1 位作者 Jing Li Dingshan Yu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2020年第10期243-247,共5页
Herein,we for the first time demonstrate the synthesis of exfoliated C4N nanosheets via a top-down approach and exploit their use as a new class of organic polymeric catalyst for the oxygen reduction reaction(ORR).The... Herein,we for the first time demonstrate the synthesis of exfoliated C4N nanosheets via a top-down approach and exploit their use as a new class of organic polymeric catalyst for the oxygen reduction reaction(ORR).The obtained C4N nanosheets are semi-conductive with a small band gap of 1.41 eV and contain abundant pyrazine-nitrogen moieties uniformly distributed throughout C4N.Density function theory calculations reveal that the intramolecular charge transfer induced by pyrazine-nitrogen in C4N enables effective charge redistribution to activate the conjugated structure and facilitate the oxygen adsorption,while the exfoliated sheet-like C4N formation renders improved electrochemical active surface area and results in high exposure of active sites.As a result,despite the bulk C4N is not active,the sheet-like C4N yield markedly improved ORR performance,even on a par with the commercial Pt/C catalyst.Our recent findings not only enrich the family members of two-dimensional conjugated polymer nanosheets but also open up new opportunity to explore new metal-free organic polymeric materials for efficient oxygen reduction catalysis and beyond. 展开更多
关键词 Oxygen reduction reaction metal-free electrocatalyst Polymeric electrocatalysts C4N nanosheets Pyrazine-nitrogen
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Tuning electronic structure of RuO_(2)by single atom Zn and oxygen vacancies to boost oxygen evolution reaction in acidic medium 被引量:1
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作者 Qing Qin Tiantian Wang +7 位作者 Zijian Li Guolin Zhang Haeseong Jang Liqiang Hou Yu Wang Min Gyu Kim Shangguo Liu Xien Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第1期94-102,I0003,共10页
The poor stability of RuO_(2)electrocatalysts has been the primary obstacles for their practical application in polymer electrolyte membrane electrolyzers.To dramatically enhance the durability of RuO_(2)to construct ... The poor stability of RuO_(2)electrocatalysts has been the primary obstacles for their practical application in polymer electrolyte membrane electrolyzers.To dramatically enhance the durability of RuO_(2)to construct activity-stability trade-off model is full of significance but challenging.Herein,a single atom Zn stabilized RuO_(2)with enriched oxygen vacancies(SA Zn-RuO_(2))is developed as a promising alternative to iridium oxide for acidic oxygen evolution reaction(OER).Compared with commercial RuO_(2),the enhanced Ru–O bond strength of SA Zn-RuO_(2)by forming Zn-O-Ru local structure motif is favorable to stabilize surface Ru,while the electrons transferred from Zn single atoms to adjacent Ru atoms protects the Ru active sites from overoxidation.Simultaneously,the optimized surrounding electronic structure of Ru sites in SA ZnRuO_(2)decreases the adsorption energies of OER intermediates to reduce the reaction barrier.As a result,the representative SA Zn-RuO_(2)exhibits a low overpotential of 210 mV to achieve 10 mA cm^(-2)and a greatly enhanced durability than commercial RuO_(2).This work provides a promising dual-engineering strategy by coupling single atom doping and vacancy for the tradeoff of high activity and catalytic stability toward acidic OER. 展开更多
关键词 ELECTROCATALYST Acidic oxygen evolution reaction Electronic structure engineering DURABILITY reaction barrier
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Nanocarbon-based metal-free and non-precious metal bifunctional electrocatalysts for oxygen reduction and oxygen evolution reactions 被引量:2
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作者 Yansong Zhu Bingsen Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第7期610-628,共19页
The oxygen reduction/evolution reactions(ORR/OER) are a key electrode process in the development of electrochemical energy conversion and storage devices,such as metal-air batteries and reversible fuel cells.The searc... The oxygen reduction/evolution reactions(ORR/OER) are a key electrode process in the development of electrochemical energy conversion and storage devices,such as metal-air batteries and reversible fuel cells.The search for low-cost high-performance nanocarbon-based metal-free and non-precious metal bifunctional electrocatalysts for ORR/OER alternatives to the widely-used noble metal-based catalysts is a research focus.This review aims to outline the opportunities and available options for these nanocarbon-based bifunctional electrocatalysts.Through discussion of some current scientific issues,we summarize the development and breakthroughs of these electrocatalysts.Then we provide our perspectives on these issues and suggestions for some areas in the further work.We hope that this review can improve the interest in nanocarbon-based metal-free and non-precious metal bifunctional electrocatalysts for ORR/OER. 展开更多
关键词 Nanocarbon-based Oxygen reduction/evolution Bifunctional electrocatalyst metal-free Non-precious metal
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Deformable Catalytic Material Derived from Mechanical Flexibility for Hydrogen Evolution Reaction 被引量:2
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作者 Fengshun Wang Lingbin Xie +7 位作者 Ning Sun Ting Zhi Mengyang Zhang Yang Liu Zhongzhong Luo Lanhua Yi Qiang Zhao Longlu Wang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第2期287-311,共25页
Deformable catalytic material with excellent flexible structure is a new type of catalyst that has been applied in various chemical reactions,especially electrocatalytic hydrogen evolution reaction(HER).In recent year... Deformable catalytic material with excellent flexible structure is a new type of catalyst that has been applied in various chemical reactions,especially electrocatalytic hydrogen evolution reaction(HER).In recent years,deformable catalysts for HER have made great progress and would become a research hotspot.The catalytic activities of deformable catalysts could be adjustable by the strain engineering and surface reconfiguration.The surface curvature of flexible catalytic materials is closely related to the electrocatalytic HER properties.Here,firstly,we systematically summarized self-adaptive catalytic performance of deformable catalysts and various micro–nanostructures evolution in catalytic HER process.Secondly,a series of strategies to design highly active catalysts based on the mechanical flexibility of lowdimensional nanomaterials were summarized.Last but not least,we presented the challenges and prospects of the study of flexible and deformable micro–nanostructures of electrocatalysts,which would further deepen the understanding of catalytic mechanisms of deformable HER catalyst. 展开更多
关键词 Deformable catalytic material Micro-nanostructures evolution Mechanical flexibility Hydrogen evolution reaction
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Nitrogen-Doped Graphene Foam as a Metal-Free Catalyst for Reduction Reactions under a High Gravity Field 被引量:2
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作者 Zhiyong Wang Zhijian Zhao +3 位作者 Jesse Baucom Dan Wang Liming Dai Jian-Feng Chen 《Engineering》 SCIE EI 2020年第6期680-687,共8页
Herein,we report on the effect of a high gravity field on metal-free catalytic reduction,taking the nitrobenzene(NB)reduction and methylene blue(MB)degradation as model reactions in a highgravity rotating tube reactor... Herein,we report on the effect of a high gravity field on metal-free catalytic reduction,taking the nitrobenzene(NB)reduction and methylene blue(MB)degradation as model reactions in a highgravity rotating tube reactor packed with three-dimensional(3D)nitrogen-doped graphene foam(NGF)as a metal-free catalyst.The apparent rate constant(kapp)of the metal-free catalytic reduction of NB in the rotating tube reactor under a high gravity level of 6484g(g=9.81 m s-2)was six times greater than that in a conventional stirred reactor(STR)under gravity.Computational fluid dynamics(CFD)simulations indicated that the improvement of the catalytic efficiency was attributed to the much higher turbulent kinetic energy and faster surface renewal rate in the high-gravity tube reactor in comparison w让h those in a conventional STR.The structure of the 3D metal-free catalysts was stable during the reaction process under a high gravity field,as confirmed by X-ray photoelectron spectroscopy(XPS)and Raman spectra.In the other model reaction,the rate of MB degradation also increased as the high gravity level in creased gradually,which aligns with the result for the NB catalytic reduction system.These results demonstrate the potential to use a high-gravity rotating packed tube reactor for the process intensification of metal-free catalytic reduction reactions. 展开更多
关键词 High-gravity technology Process intensification metal-free catalysts Carbon nanomateriais Catalytic reduction
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“Buckets effect”in the kinetics of electrocatalytic reactions 被引量:1
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作者 Haowen Cui Yan-Xia Chen 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第2期388-396,I0010,共10页
In this study,we systematically investigated the effect of proton concentration on the kinetics of the oxygen reduction reaction(ORR)on Pt(111)in acidic solutions.Experimental results demonstrate a rectangular hyperbo... In this study,we systematically investigated the effect of proton concentration on the kinetics of the oxygen reduction reaction(ORR)on Pt(111)in acidic solutions.Experimental results demonstrate a rectangular hyperbolic relationship,i.e.,the ORR current excluding the effect of other variables increases with proton concentration and then tends to a constant value.We consider that this is caused by the limitation of ORR kinetics by the trace oxygen concentration in the solution,which determines the upper limit of ORR kinetics.A model of effective concentration is further proposed for rectangular hyperbolic relationships:when the reactant concentration is high enough to reach a critical saturation concentration,the effective reactant concentration will become a constant value.This could be due to the limited concentration of a certain reactant for reactions involving more than one reactant or the limited number of active sites available on the catalyst.Our study provides new insights into the kinetics of electrocatalytic reactions,and it is important for the proper evaluation of catalyst activity and the study of structureperformance relationships. 展开更多
关键词 Oxygen reduction reaction KINETICS Zero order Rectangular hyperbolic relationship pH effect
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Red-blood-cell-like nitrogen-doped porous carbon as an efficient metal-free catalyst for oxygen reduction reaction 被引量:1
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作者 WANG Li-ping TIAN Jing +5 位作者 LI Jing-sha ZENG Xian-guang PENG Zhi-guang HUANG Xiao-bing TANG You-gen WANG Hai-yan 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第6期1458-1468,共11页
A red-blood-cell-like nitrogen-doped porous carbon catalyst with a high nitrogen content(9.81%)and specific surface area(631.46 m^2/g)was prepared by using melamine cyanuric acid and glucose as sacrificial template an... A red-blood-cell-like nitrogen-doped porous carbon catalyst with a high nitrogen content(9.81%)and specific surface area(631.46 m^2/g)was prepared by using melamine cyanuric acid and glucose as sacrificial template and carbon source,respectively.This catalyst has a comparable onset potential and a higher diffusion-limiting current density than the commercial 20 wt%Pt/C catalyst in alkaline electrolyte.The oxygen reduction reaction mechanism catalyzed by this catalyst is mainly through a 4e pathway process.The excellent catalytic activity could origin from the synergistic effect of the in-situ doped nitrogen(up to 9.81%)and three-dimensional(3D)porous network structure with high specific surface area,which is conducive to the exposure of more active sites.It is interesting to note that the catalytic activity of oxygen reduction strongly depends on the proportion of graphic N rather than the total N content. 展开更多
关键词 oxygen reduction reaction nitrogen-doped carbon porous structure red-blood-cell-like morphology
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The reaction mechanism and interfacial crystallization of Al nanoparticle-embedded Ni under shock loading
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作者 Yifan Xie Jian-Li Shao +1 位作者 Rui Liu Pengwan Chen 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期114-124,共11页
The shock-induced reaction mechanism and characteristics of Ni/Al system,considering an Al nanoparticle-embedded Ni single crystal,are investigated through molecular dynamics simulation.For the shock melting of Al nan... The shock-induced reaction mechanism and characteristics of Ni/Al system,considering an Al nanoparticle-embedded Ni single crystal,are investigated through molecular dynamics simulation.For the shock melting of Al nanoparticle,interfacial crystallization and dissolution are the main characteristics.The reaction degree of Al particle first increases linearly and then logarithmically with time driven by rapid mechanical mixing and following dissolution.The reaction rate increases with the decrease of particle diameter,however,the reaction is seriously hindered by interfacial crystallization when the diameter is lower than 9 nm in our simulations.Meanwhile,we found a negative exponential growth in the fraction of crystallized Al atoms,and the crystallinity of B2-NiAl(up to 20%)is positively correlated with the specific surface area of Al particle.This can be attributed to the formation mechanism of B2-NiAl by structural evolution of finite mixing layer near the collapsed interface.For shock melting of both Al particle and Ni matrix,the liquid-liquid phase inter-diffusion is the main reaction mechanism that can be enhanced by the formation of internal jet.In addition,the enhanced diffusion is manifested in the logarithmic growth law of mean square displacement,which results in an almost constant reaction rate similar to the mechanical mixing process. 展开更多
关键词 Shock-induced reaction Molecular dynamics simulations Interfacial crystallization reaction mechanism
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Metal-organic-framework-derived copper-based catalyst for multicomponent C-S coupling reaction
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作者 Lixin Chen Hui Zhang +1 位作者 Linxi Hou Xin Ge 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第6期1-8,共8页
Copper-based metal-organic frameworks(Cu-MOFs)are a promising multiphase catalyst for catalyzing C-S coupling reactions by virtue of their diverse structures and functions.However,the unpleasant odor and instability o... Copper-based metal-organic frameworks(Cu-MOFs)are a promising multiphase catalyst for catalyzing C-S coupling reactions by virtue of their diverse structures and functions.However,the unpleasant odor and instability of the organosulfur,as well as the mass-transfer resistance that exists in multiphase catalysis,have often limited the catalytic application of Cu-MOFs in C-S coupling reactions.In this paper,a Cu-MOFs catalyst modified by cetyltrimethylammonium bromide(CTAB)was designed to enhance mass transfer by increasing the adsorption of organic substrates using the long alkanes of CTAB.Concurrently,elemental sulfur was used to replace organosulfur to achieve a highly efficient and atom-economical multicomponent C-S coupling reaction. 展开更多
关键词 Design Copper-based metal-organic frameworks (Cu-MOFs) Adsorption C-S coupling reaction Multiphase reaction
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Influence of initial check, information exchange, final accuracy check, reaction information nursing on the psychology of elderly with lung cancer 被引量:1
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作者 Cui Jiang Jing Ma +1 位作者 Wen He Hai-Ying Zhang 《World Journal of Clinical Cases》 SCIE 2024年第4期737-745,共9页
BACKGROUND As one of the fatal diseases with high incidence,lung cancer has seriously endangered public health and safety.Elderly patients usually have poor self-care and are more likely to show a series of psychologi... BACKGROUND As one of the fatal diseases with high incidence,lung cancer has seriously endangered public health and safety.Elderly patients usually have poor self-care and are more likely to show a series of psychological problems.AIM To investigate the effectiveness of the initial check,information exchange,final accuracy check,reaction(IIFAR)information care model on the mental health status of elderly patients with lung cancer.METHODS This study is a single-centre study.We randomly recruited 60 elderly patients with lung cancer who attended our hospital from January 2021 to January 2022.These elderly patients with lung cancer were randomly divided into two groups,with the control group taking the conventional propaganda and education and the observation group taking the IIFAR information care model based on the conventional care protocol.The differences in psychological distress,anxiety and depression,life quality,fatigue,and the locus of control in psychology were compared between these two groups,and the causes of psychological distress were analyzed.RESULTS After the intervention,Distress Thermometer,Hospital Anxiety and Depression Scale(HADS)for anxiety and the HADS for depression,Revised Piper’s Fatigue Scale,and Chance Health Locus of Control scores were lower in the observation group compared to the pre-intervention period in the same group and were significantly lower in the observation group compared to those of the control group(P<0.05).After the intervention,Quality of Life Questionnaire Core 30(QLQ-C30),Internal Health Locus of Control,and Powerful Others Health Locus of Control scores were significantly higher in the observation and the control groups compared to the pre-intervention period in their same group,and QLQ-C30 scores were significantly higher in the observation group compared to those of the control group(P<0.05).CONCLUSION The IIFAR information care model can help elderly patients with lung cancer by reducing their anxiety and depression,psychological distress,and fatigue,improving their tendencies on the locus of control in psychology,and enhancing their life qualities. 展开更多
关键词 Initial check information exchange final accuracy check reaction information care model Lung cancer Mental health
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