The Experts below are selected from a list of 38055 Experts worldwide ranked by ideXlab platform
Shi-zhang Qiao - One of the best experts on this subject based on the ideXlab platform.
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hydrogen evolution by a metal free electrocatalyst
Science & Engineering Faculty, 2014Co-Authors: Yao Zheng, Lu Hua Li, Aijun Du, Yan Jiao, Mietek Jaroniec, Ying Chen, Shi-zhang QiaoAbstract:This article is free to read on the publisher's website Electrocatalytic reduction of water to molecular hydrogen via the hydrogen evolution reaction may provide a Sustainable Energy Supply for the future, but its commercial application is hampered by the use of precious platinum catalysts. All alternatives to platinum thus far are based on nonprecious metals, and, to our knowledge, there is no report about a catalyst for electrocatalytic hydrogen evolution beyond metals. Here we couple graphitic-carbon nitride with nitrogen-doped graphene to produce a metal-free hybrid catalyst, which shows an unexpected hydrogen evolution reaction activity with comparable overpotential and Tafel slope to some of well-developed metallic catalysts. Experimental observations in combination with density functional theory calculations reveal that its unusual electrocatalytic properties originate from an intrinsic chemical and electronic coupling that synergistically promotes the proton adsorption and reduction kinetics.
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hydrogen evolution by a metal free electrocatalyst
Science & Engineering Faculty, 2014Co-Authors: Yao Zheng, Yihan Zhu, Yan Jiao, Mietek Jaroniec, Yu Ji-han, Ying Chen, Shi-zhang QiaoAbstract:This article is free to read on the publisher's website Electrocatalytic reduction of water to molecular hydrogen via the hydrogen evolution reaction may provide a Sustainable Energy Supply for the future, but its commercial application is hampered by the use of precious platinum catalysts. All alternatives to platinum thus far are based on nonprecious metals, and, to our knowledge, there is no report about a catalyst for electrocatalytic hydrogen evolution beyond metals. Here we couple graphitic-carbon nitride with nitrogen-doped graphene to produce a metal-free hybrid catalyst, which shows an unexpected hydrogen evolution reaction activity with comparable overpotential and Tafel slope to some of well-developed metallic catalysts. Experimental observations in combination with density functional theory calculations reveal that its unusual electrocatalytic properties originate from an intrinsic chemical and electronic coupling that synergistically promotes the proton adsorption and reduction kinetics.
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Hydrogen evolution by a metal-free electrocatalyst
Nature Communications, 2014Co-Authors: Yao Zheng, Yihan Zhu, Lu Hua Li, Aijun Du, Yan Jiao, Mietek Jaroniec, Yu Ji-han, Ying Chen, Shi-zhang QiaoAbstract:Electrocatalytic reduction of water to molecular hydrogen via the hydrogen evolution reaction may provide a Sustainable Energy Supply for the future, but its commercial application is hampered by the use of precious platinum catalysts. All alternatives to platinum thus far are based on nonprecious metals, and, to our knowledge, there is no report about a catalyst for electrocatalytic hydrogen evolution beyond metals. Here we couple graphitic-carbon nitride with nitrogen-doped graphene to produce a metal-free hybrid catalyst, which shows an unexpected hydrogen evolution reaction activity with comparable overpotential and Tafel slope to some of well-developed metallic catalysts. Experimental observations in combination with density functional theory calculations reveal that its unusual electrocatalytic properties originate from an intrinsic chemical and electronic coupling that synergistically promotes the proton adsorption and reduction kinetics.
G Czisch - One of the best experts on this subject based on the ideXlab platform.
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combined solar power and desalination plants for the mediterranean region Sustainable Energy Supply using large scale solar thermal power plants
Desalination, 2003Co-Authors: Franz Trieb, Joachim Nitsch, Stefan Kronshage, Christoph Schillings, Larsarvid Brischke, G Knies, G CzischAbstract:The paper gives a review of concentrating solar power technologies and shows their perspectives for Sustainable development and climate protection. New concepts for the combined generation of power and water are presented together with instruments for enhanced project assessment using remote sensing technologies and geographic information systems. The vast solar Energy resources of the South can be activated by international renewable Energy alliances and allow for a smooth transition of the present electricity schemes to a Sustainable power system based on renewable Energy sources.
Markus Seitz - One of the best experts on this subject based on the ideXlab platform.
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techno economic heat transfer optimization of large scale latent heat Energy storage systems in solar thermal power plants
Applied Thermal Engineering, 2016Co-Authors: Stefan Hubner, Markus Eck, Christoph Stiller, Markus SeitzAbstract:Concentrated solar power plants with integrated storage systems are key technologies for Sustainable Energy Supply systems and reduced anthropogenic CO2-emissions. Developing technologies include direct steam generation in parabolic trough systems, which offer benefits due to higher steam temperatures and, thus, higher electrical efficiencies. However, no large scale Energy storage technology is available yet. A promising option is a combined system consisting of a state-of-the art sensible molten salt storage system and a high temperature latent heat thermal Energy storage system (LHTESS). This paper discusses the systematic development and optimization of heat transfer structures in LHTESS from a technological and economic point of view. Two evaluation parameters are developed in order to minimize the specific investment costs. First, the specific product costs determine the optimum equipment of the latent heat storage module, i.e. the finned tube. The second parameter reflects the interacting behavior of the LHTESS and the steam turbine during discharge. This behavior is described with a simplified power block model that couples both components.
Joachim Nitsch - One of the best experts on this subject based on the ideXlab platform.
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market perspectives of stationary fuel cells in a Sustainable Energy Supply system long term scenarios for germany
Energy Policy, 2006Co-Authors: Wolfram Krewi, Joachim Nitsch, Manfred Fischedick, Marti Peh, Heiner Volke TemmingAbstract:Abstract Because of high efficiency, low environmental impacts and a potential role in transforming our Energy system into a hydrogen economy, fuel cells are often considered as a key technology for a Sustainable Energy Supply. However, the future framing conditions under which stationary fuel cells have to prove their technical and economic competitiveness are most likely characterised by a reduced demand for space heating, and a growing contribution of renewable Energy sources to heat and electricity Supply, which both directly limit the potential for combined heat and power generation, and thus also for fuel cells. Taking Germany as a case study, this paper explores the market potential of stationary fuel cells under the structural changes of the Energy demand and Supply system required to achieve a Sustainable Energy Supply. Results indicate that among the scenarios analysed it is in particular a strategy oriented towards ambitious CO2-reduction targets, which due to its changes in the Supply structure is in a position to mobilise a market potential that might be large enough for a successful fuel cell commercialisation. However, under the conditions of a business-as-usual trajectory the sales targets of fuel cell manufacturers cannot be met.
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combined solar power and desalination plants for the mediterranean region Sustainable Energy Supply using large scale solar thermal power plants
Desalination, 2003Co-Authors: Franz Trieb, Joachim Nitsch, Stefan Kronshage, Christoph Schillings, Larsarvid Brischke, G Knies, G CzischAbstract:The paper gives a review of concentrating solar power technologies and shows their perspectives for Sustainable development and climate protection. New concepts for the combined generation of power and water are presented together with instruments for enhanced project assessment using remote sensing technologies and geographic information systems. The vast solar Energy resources of the South can be activated by international renewable Energy alliances and allow for a smooth transition of the present electricity schemes to a Sustainable power system based on renewable Energy sources.
Xin-bo Zhang - One of the best experts on this subject based on the ideXlab platform.
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High-Performance Integrated Self-Package Flexible Li–O2 Battery Based on Stable Composite Anode and Flexible Gas Diffusion Layer
Advanced Materials, 2017Co-Authors: Xiao-yang Yang, Da Peng Liu, Di Bao, Ji-jing Xu, Zhi-wen Chang, Yu Zhang, Xin-bo ZhangAbstract:With the rising development of flexible and wearable electronics, corresponding flexible Energy storage devices with high Energy density are required to provide a Sustainable Energy Supply. Theoretically, rechargeable flexible Li-O-2 batteries can provide high specific Energy density; however, there are only a few reports on the construction of flexible Li-O-2 batteries. Conventional flexible Li-O-2 batteries possess a loose battery structure, which prevents flexibility and stability. The low mechanical strength of the gas diffusion layer and anode also lead to a flexible Li-O-2 battery with poor mechanical properties. All these attributes limit their practical applications. Herein, the authors develop an integrated flexible Li-O-2 battery based on a high-fatigue-resistance anode and a novel flexible stretchable gas diffusion layer. Owing to the synergistic effect of the stable electrocatalytic activity and hierarchical 3D interconnected network structure of the free-standing cathode, the obtained flexible Li-O-2 batteries exhibit superior electrochemical performance, including a high specific capacity, an excellent rate capability, and exceptional cycle stability. Furthermore, benefitting from the above advantages, the as-fabricated flexible batteries can realize excellent mechanical and electrochemical stability. Even after a thousand cycles of the bending process, the flexible Li-O-2 battery can still possess a stable open-circuit voltage, a high specific capacity, and a durable cycle performance.
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liquid phase chemical hydrogen storage catalytic hydrogen generation under ambient conditions
Chemsuschem, 2010Co-Authors: Hai-long Jiang, Sanjay Kumar Singh, Jun-min Yan, Xin-bo ZhangAbstract:There is a demand for a sufficient and Sustainable Energy Supply. Hence, the search for applicable hydrogen storage materials is extremely important owing to the diversified merits of hydrogen Energy. Lithium and sodium borohydride, ammonia borane, hydrazine, and formic acid have been extensively investigated as promising hydrogen storage materials based on their relatively high hydrogen content. Significant advances, such as hydrogen generation temperatures and reaction kinetics, have been made in the catalytic hydrolysis of aqueous lithium and sodium borohydride and ammonia borane as well as in the catalytic decomposition of hydrous hydrazine and formic acid. In this Minireview we briefly survey the research progresses in catalytic hydrogen generation from these liquid-phase chemical hydrogen storage materials.
