检索结果-南通市图书馆

Iridium oxide fabrication and application: A review

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2020年第7期29卷 152-172,I0005页

作者： Hansaem Jang Jaeyoung Lee Electrochemical Reaction&Technology Laboratory(ertl) School of Earth Sciences and Environmental EngineeringGwangju Institute of Science and Technology(GIST)Gwangju 61005Republic of Korea Ertl Center for Electrochemistry and Catalysis GRIGISTGwangju 61005Republic of Korea

Despite the scarcity and cost of iridium oxide,it is still the material of choice in numerous fields of science and applications,including capacitors,electrochromism,sensors,and various oxidation electrocatalysis(e.g.,chlorine evolution reaction,detoxification,and oxygen evolution reaction).Such versatility is attributed to the distinct features of iridium oxides,such as their activity,biocompatibility,conductivity,and durability.The features and properties of iridium oxides are strongly dependent on the fabrication method.In this review,methodologies relating to the synthesis and fabrication of solid-state iridium oxides have been thoroughly collected and discussed.Structuring and crystallization techniques for iridium oxides are also noted.At the end of the review,the effects of utilizing a certain fabrication method on the characteristics of the iridium oxide product are recapitulated,together with the recommended application of the product in various fields.

关键词： Iridium oxide Iridium dioxide Electrode Electrocatalyst Electrochromism pH sensor Oxygen evolution reaction

Electro-oxidation of mixed reactants of ethanol and formate on Pd/C in alkaline fuel cells

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2016年第4期25卷 683-690页

作者： Myounghoon Choun Jaeyoung Lee Electrochemical Reaction and Technology Laboratory School of Environmental Science and Engineering GIST Ertl Center for Electrochemistry and Catalysis Research Institute for Solar and Sustainable Energies (RISE) GIST

Direct ethanol fuel cells have attracted attention as an alternative energy technology due to several advantages such as high theoretical energy density and abundant supply of ethanol.In spite of the advantages,commercialization of direct ethanol fuel cells is hampered by the relatively low performance caused by its slow oxidation kinetics and difficulty of complete oxidation.In this study,formate,which has relatively faster oxidation kinetics,was mixed with ethanol to compensate the latter’s sluggish kinetics.Effects of p H,concentration,scan rate,and temperature on the mixed reactants oxidation on Pd were investigated by electrochemical experiments such as potential sweep and potentiostatic methods.Furthermore,the potential of the mixed reactants as fuel was evaluated by single cell experiments.As a result,we demonstrate that mixing formate with ethanol results in enhanced power performance in a single cell system.

关键词： Ethanol Formate Mixed reactants Alkaline media Palladium Electro-oxidation

Enhanced reversible capacity of Li-S battery cathode based on graphene oxide

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2013年第2期22卷 336-340页

作者： Jin Won Kim Joey D. Ocon Dong-Won Park Jaeyoung Lee School of Environmental Science and Engineering Laboratory for Energy Storage Systems Ertl Center for Electrochemistry and Catalysis RISE Gwangju Institute of Science and Technology

Lithium sulfur battery （LSB） offers several advantages such as very high energy density, low-cost, and environmental-friendliness. However, it suffers from serious degradation of its reversible capacity because of the dissolution of reaction intermediates, lithium polysulfides, into the electrolyte. To solve this limitation, there are many studies using graphene-based materials due to their excellent mechanical strength and high conductivity. Compared with graphene, graphene oxide （GO） contains various oxygen functional groups, which enhance the reaction with lithium polysulfides. Here, we investigated the positive effect of using GO mixed with carbon black on the performance of cathode in LSB. We have observed a smaller drop of capacity in GO mixed sulfur cathode. We further demonstrate that the mechanistic origin of reversibility improvement, as confirmed through CV and Raman spectra, can be explained by the stabilization of sulfur in lithium polysulfide intermediates by oxygen functional groups of GO to prevent dissolution. Our findings suggest that the use of graphene oxide-based cathode is a promising route to significantly improve the reversibility of current LSB.

关键词： lithiums sulfur battery graphene oxide capacity fading lithium polysulfide dissolution

High-temperature liquid Sn-air energy storage cell

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2015年第5期24卷 614-619页

作者： HyungKuk Ju Jaeyoung Lee Ertl Center for Electrochemistry and Catalysis Research Institute for Solar and Sustainable Energies (RISE) Gwangju Institute of Science and Technology Electrochemical Reaction and Technology Laboratory (ertl) School of Environmental Science and Engineering Gwangju Institute of Science and Technology

A new type of a high temperature liquid metal-air energy storage cell based on solid oxide electrolyte has been successfully demonstrated at 750 ℃ by feeding metal Sn. In order to understanding the initial size effect of metal as a liquid fuel, we report here the impact of the thermal and electrochemical oxidation behavior of nano Sn （-100 nm）, comparing with micro-sized （-5 μm） and macro-sized （4350 μm） Sn. The thermogravimetric analysis and the monitoring OCV test indicate that the distinct property of nano-sized Sn results in a favorable thermal oxidation behavior near the melting point and a promising power performance due to enhanced fuel transport to the anode. However, the accumulated Sn oxide at the reaction interface during a discharge test towards the limitation of further electrochemical oxidation.

关键词： Nano tin Metal-air battery Solid oxide electrolyte Thermal oxidation Discharge behavior

Atomic layer deposition of ultrathin layered TiO_2 on Pt/C cathode catalyst for extended durability in polymer electrolyte fuel cells

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2016年第2期25卷 256-262页

作者： Sangho Chung Myounghoon Choun Beomgyun Jeong Jae Kwang Lee Jaeyoung Lee Electrochemical Reaction and Technology Laboratory School of Environmental Science and TechnologyGwangju Institute of Science and Technology Ertl Center for Electrochemistry and Catalysis Research Institute for Solar and sustainable EnergiesGwangju Institute of Science and Technology

This study shows the preparation of a TiO2 coated Pt/C（TiO2/Pt/C） by atomic layer deposition（ALD）,and the examination of the possibility for TiO2/Pt/C to be used as a durable cathode catalyst in polymer electrolyte fuel cells（PEFCs）. Cyclic voltammetry results revealed that TiO2/Pt/C catalyst which has 2 nm protective layer showed similar activity for the oxygen reduction reaction compared to Pt/C catalysts and they also had good durability. TiO2/Pt/C prepared by 10 ALD cycles degraded 70% after 2000 Accelerated degradation test, while Pt/C corroded 92% in the same conditions. TiO2 ultrathin layer by ALD is able to achieve a good balance between the durability and activity, leading to TiO2/Pt/C as a promising cathode catalyst for PEFCs. The mechanism of the TiO2 protective layer used to prevent the degradation of Pt/C is discussed.

关键词： Polymer electrolyte hydrogen fuel cells Atomic layer deposition Gas diffusion layer Protective layer Titanium dioxide

Development of high quality Fe_3O_4/rGO composited electrode for low energy water treatment

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2016年第3期25卷 354-360页

作者： Ngoc Tuan Trinh Sangho Chung Jae Kwang Lee Jaeyoung Lee Electrochemical Reaction and Technology Laboratory School of Environmental Science and Technology Gwangju Institute of Science and Technology (GIST) center for Chemical Energy Storage System Research Institute for Solar and Sustainable Energies GIST Ertl Center for Electrochemistry and Catalysis GIST

Electrochemical water treatment is an attractive technology for water desalination and softening due to its low energy consumption. Especially, capacitive Deionization(CDI) is promising as a future technology for water treatment. Graphene(rGO) has been intensively studied for CDI electrode because of its advantages such as excellent electrical conductivity and high specific surface area. However, its 2D dimensional structure with small specific capacitance, high resistance between layers and hydrophobicity degrades ion adsorption efficiency. In this work, we successfully prepared uniformly dispersed Fe3O4/rGO nanocomposite by simple thermal reactions and applied it as effective electrodes for CDI. Iron oxides play a role in uniting graphene sheets, and specific capacitance and wettability of electrodes are improved significantly;hence CDI performances are enhanced. The hardness removal of Fe3O4/rGO nanocomposite electrodes can reach 4.3 mg/g at applied voltage of 1.5V, which is 3 times higher than that of separate r GO electrodes.Thus this material is a promising candidate for water softening technology.

关键词： Electrochemical water treatment Capacitive deionization Water softening Grapheme Fe_3O_4/rGO nanocomposite Fe_3O_4 nanoparticle

Positively charged carbon electrocatalyst for enhanced power performance of L-ascorbic acid fuel cells

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2016年第5期25卷 793-797页

作者： Myounghoon Choun Hye Jin Lee Jaeyoung Lee Electrochemical Reaction and Technology Laboratory School of Environmental Science and Engineering GIST Department of Chemistry and Green-Nano Materials Research center Kyungpook National University Ertl Center for Electrochemistry and Catalysis Research Institute for Solar and Sustainable Energies (RISE) GIST

Carbon surface with large oxygen and carbon ratio(O/C) indicated an outstanding electro-catalytic activity toward L-ascorbic acid oxidation, compared to platinum group metals. However, interrelation of surface functional groups and its electro-catalytic activity is still unclear. In this paper, we prepared different levels of oxidized carbons by a simple acid treatment and investigated the correlation between the surface oxygen functional groups of acid-treated carbon and electro-catalytic activity in an electrooxidation of L-ascorbic acid. Positively charged carbon was demonstrated by lone pair electron of oxygen from valence band spectra study. It was revealed that the positively charged carbon, especially involved in carbonyl, showed enhanced the electro-catalytic activity through both better adsorption of negatively charged reactants and lowered LUMO by electronegativity of oxygen.

关键词： Vitamin-C electrooxidation Electronegativity Carbon Atomic charge Surface oxygen

100 W-class green hydrogen production from ammonia at a dual-layer electrode containing a Pt-Ir catalyst for an alkaline electrolytic process

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第6期93卷 352-360页

作者： Donghyun Yoon Sunki Chung Minjun Choi Eunhyeok Yang Jaeyoung Lee School of Earth Sciences and Environmental Engineering Gwangju Institute of Science and Technology (GIST) International Future Research center of Chemical Energy Storage and Conversion Processes GIST Ertl Center for Electrochemistry and Catalysis GIST TKG Huchems Co.Ltd

Ammonia allows storage and transport of hydrogen over long distances and is an attractive potential hydrogen carrier.Electrochemical decomposition has recently been used for the conversion of ammonia to hydrogen and is regarded as a future technology for production of CO2-free pure hydrogen.Herein,a heterostructural Pt-Ir dual-layer electrode is developed and shown to achieve successful long-term operation in an ammonia electrolyzer with an anion exchange membrane(AEM).This electrolyzer consisted of eight membra ne electrode assemblies(MEAs) with a total geometric area of 200 cm2on the anode side,which resulted in a hydrogen production rate of 25 L h-1.We observed the degradation in MEA performance attributed to changes in the anode catalyst layer during hydrogen production via ammonia electrolysis.Furthermore,we demonstrated the relationship between the ammonia oxidation reaction(AOR)and the oxygen evolution reaction(OER).

关键词： Ammonia oxidation Dual-layer catalyst Electrolytic process Green hydrogen Oxygen evolution reaction

Optimistic performance of carbon-free hydrazine fuel cells based on controlled electrode structure and water management

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2020年第12期29卷 175-181页

作者： Hongsun Hwang Sujik Hong Do-Hyeong Kim Moon-Sung Kang Jin-Soo Park Sunghyun Uhm Jaeyoung Lee Electrochemical Reaction and Technology Laboratory(ertl) School of Earth Sciences and Environmental EngineeringGwangju Institute of Science and Technology(GIST)Cwangju 61005Republic of Korea Ertl Center for Electrochemistry and Catalysis Gwangju Institute of Science and Technology(GIST)Gwangju 61005Republic of Korea Department of Green Chemical Engineering Sangmyung UniversityCheonanChungnam 31066Republic of Korea Plant Engineering center Institute for Advanced EngineeringYongin 17180Republic of Korea

In this study, we first attempted to discover the optimal configuration of membrane-electrode assemblies(MEAs) used to achieve a high performance of direct hydrazine fuel cells(DHFCs). We have investigated the effect of water management and the electrode thickness on the performance of DHFCs, depending on the hydrophobicity of the gas diffusion layers in the cathode and the catalyst loading in the anode with the carbon-supported Ni, synthesized by a polyol process. With the optimal water management and electrode thickness, the MEA constructed using the as-prepared Ni/C anode catalyst containing the metallic and low oxidative state and ultra-low Pt loading cathode reduced the ohmic resistance and mass transfer limitation in the current-voltage curves observed for the alkaline DHFC, achieving an impressive power performance over 500 mW cm^(–2).

关键词： Fuel cell Hydrazine Alkaline media Membrane-electrode assembly