Solar-hydrogen system has great potential for contributing to sustainable and clean energy supply. The aim of this study is to clarify the impact of heat transfer media in solar collector such as methane, ammonium, hy...Solar-hydrogen system has great potential for contributing to sustainable and clean energy supply. The aim of this study is to clarify the impact of heat transfer media in solar collector such as methane, ammonium, hydrogen, air and water on the performance of solar-hydrogen system. After estimating the highest temperature attainable by each heat transfer media, the amount of thermal energy that could be saved in the production of hydrogen or preheat for power generation by fuel cell was calculated. The power generation performance of fuel cell using each heat transfer media was also investigated. As a result, it has been revealed that the temperature changes of methane, ammonium and air follow the horizontal solar radiation intensity irrespective of seasons, and their highest temperatures are almost the same among them. The temperature response of hydrogen is slower than methane, ammonium and air. This study defines the ratio of saving thermal energy which indicates the effect of solar thermal utilization for production of hydrogen or preheat for power generation by fuel cell without using utility gas. It has been found that the biggest thermal energy saving is obtained when hydrogen and air are used as the heat transfer media. The power generated by PEFC system per effective area of evacuated tube collector in the case of using methane or ammonium is 3.309×10-2 kWh/m2 and 2.076×10-2 kWh/m2, respectively, while it is 2.466×10-2 kWh in the case of using hydrogen and air.展开更多
The performance of an electrocatalyst, which is needed e.g. for key energy conversion reactions such as hydrogen evolution, oxygen reduction or CO2 reduction, is determined not only by the inherent structure of active...The performance of an electrocatalyst, which is needed e.g. for key energy conversion reactions such as hydrogen evolution, oxygen reduction or CO2 reduction, is determined not only by the inherent structure of active sites but also by the properties of the interfacial structures at catalytic surfaces. Ionic liquids（ILs）, as a unique class of metal salts with melting point below 100 ℃, present themselves as ideal modulators for manipulations of the interfacial structures. Due to their excellent properties such as good chemical stability, high ionic conductivity, wide electrochemical windows and tunable solvent properties the performance of electrocatalysts can be substantially improved through ILs. In the current minireview, we highlight the critical role of the IL phase at the microenvironments created by the IL, the liquid electrolyte, catalytic nanoparticles and/or support materials, by detailing the promotional effect of IL in electrocatalysis as reaction media, binders, and surface modifiers. Updated exemplary applications of IL in electrocatalysis are given and moreover, the latest developments of IL modified electrocatalysts following the ＂Solid Catalyst with Ionic Liquid Layer（SCILL）＂ concept are presented.展开更多
文摘Solar-hydrogen system has great potential for contributing to sustainable and clean energy supply. The aim of this study is to clarify the impact of heat transfer media in solar collector such as methane, ammonium, hydrogen, air and water on the performance of solar-hydrogen system. After estimating the highest temperature attainable by each heat transfer media, the amount of thermal energy that could be saved in the production of hydrogen or preheat for power generation by fuel cell was calculated. The power generation performance of fuel cell using each heat transfer media was also investigated. As a result, it has been revealed that the temperature changes of methane, ammonium and air follow the horizontal solar radiation intensity irrespective of seasons, and their highest temperatures are almost the same among them. The temperature response of hydrogen is slower than methane, ammonium and air. This study defines the ratio of saving thermal energy which indicates the effect of solar thermal utilization for production of hydrogen or preheat for power generation by fuel cell without using utility gas. It has been found that the biggest thermal energy saving is obtained when hydrogen and air are used as the heat transfer media. The power generated by PEFC system per effective area of evacuated tube collector in the case of using methane or ammonium is 3.309×10-2 kWh/m2 and 2.076×10-2 kWh/m2, respectively, while it is 2.466×10-2 kWh in the case of using hydrogen and air.
基金supported by the funding of the German Research Council (DFG), which, within the framework of its Excellence Initiative, supports the Cluster of Excellence “Engineering of Advanced Materials” (www.eam.uni-erlangen.de) at the University of Erlangen-Nürnberg
文摘The performance of an electrocatalyst, which is needed e.g. for key energy conversion reactions such as hydrogen evolution, oxygen reduction or CO2 reduction, is determined not only by the inherent structure of active sites but also by the properties of the interfacial structures at catalytic surfaces. Ionic liquids（ILs）, as a unique class of metal salts with melting point below 100 ℃, present themselves as ideal modulators for manipulations of the interfacial structures. Due to their excellent properties such as good chemical stability, high ionic conductivity, wide electrochemical windows and tunable solvent properties the performance of electrocatalysts can be substantially improved through ILs. In the current minireview, we highlight the critical role of the IL phase at the microenvironments created by the IL, the liquid electrolyte, catalytic nanoparticles and/or support materials, by detailing the promotional effect of IL in electrocatalysis as reaction media, binders, and surface modifiers. Updated exemplary applications of IL in electrocatalysis are given and moreover, the latest developments of IL modified electrocatalysts following the ＂Solid Catalyst with Ionic Liquid Layer（SCILL）＂ concept are presented.
