In the field of rail transit,the UK Department of Transport stated that it will realize a comprehensive transformation of UK railways by 2050,abandoning traditional diesel trains and upgrading them to new environmenta...In the field of rail transit,the UK Department of Transport stated that it will realize a comprehensive transformation of UK railways by 2050,abandoning traditional diesel trains and upgrading them to new environmentally friendly trains.The current mainstream upgrade methods are electrification and hydrogen fuel cells.Comprehensive upgrades are costly,and choosing the optimal upgrade method for trams and mainline railways is critical.Without a sensitivity analysis,it is difficult for us to determine the influence relationship between each parameter and cost,resulting in a waste of cost when choosing a line reconstruction method.In addition,by analyzing the sensitivity of different parameters to the cost,the primary optimization direction can be determined to reduce the cost.Global higher-order sensitivity analysis enables quantification of parameter interactions,showing non-additive effects between parameters.This paper selects the main parameters that affect the retrofit cost and analyzes the retrofit cost of the two upgrade methods in the case of trams and mainline railways through local and global sensitivity analysis methods.The results of the analysis show that,given the current UK rail system,it is more economical to choose electric trams and hydrogen mainline trains.For trams,the speed at which the train travels has the greatest impact on the final cost.Through the sensitivity analysis,this paper provides an effective data reference for the current railway upgrading and reconstruction plan and provides a theoretical basis for the next step of train parameter optimization.展开更多
Escalating apprehension about the harmful effects of widespread use of conventional fossil fuels in the marine field and in internal combustion engines in general, has led to a vast amount of efforts and the directing...Escalating apprehension about the harmful effects of widespread use of conventional fossil fuels in the marine field and in internal combustion engines in general, has led to a vast amount of efforts and the directing of large capital investment towards research and development of sustainable alternative energy sources. One of the most promising and abundant of these sources is hydrogen. Firstly, the use of current fossil fuels is. discussed focusing on the emissions and economic sides to emphasize the need for a new, cleaner and renewable fuel with particular reference to hydrogen as a suitable possible alternative. Hydrogen properties, production and storage methods are then reviewed along with its suitability from the economical point of view. Finally, a cost analysis for the use of hydrogen in internal combustion engines is carried out to illustrate the benefits of its use as a replacement for diesel. The outcome of this cost analysis shows that 98% of the capital expenditure is consumed by the equipment, and 68.3% of the total cost of the equipment is spent on the solar photovoltaic cells. The hydrogen plant is classified as a large investment project because of its high initial cost which is about 1 billion US$; but this is justified because hydrogen is produced in a totally green way. When hydrogen is used as a fuel, no harmful emissions are obtained.展开更多
Fuel cells are considered to be one of the ideal alternatives to traditional fossil energy conversion devices.Membrane electrodes are the core components in the hydrogen fuel cells.Our work reported the synthesis of t...Fuel cells are considered to be one of the ideal alternatives to traditional fossil energy conversion devices.Membrane electrodes are the core components in the hydrogen fuel cells.Our work reported the synthesis of the Pt/C catalysts with different Pt loading,and by changing the Nafion content,hot pressing temperature and hot pressing pressure,the catalyst coated membrane(CCM)spraying process was optimized.Moreover,the three-dimensional structure model of the single battery membrane electrode was studied quantitatively,and the porous membrane electrode with gradient distribution was fabricated under optimized processing conditions,with excellent electrical performance.展开更多
This paper presents the concept of a passive electrochemical hydrogen recombiner(PEHR).The reaction energy of the recombination of hydrogen and oxygen is used as a source of electrical energy according to the operatin...This paper presents the concept of a passive electrochemical hydrogen recombiner(PEHR).The reaction energy of the recombination of hydrogen and oxygen is used as a source of electrical energy according to the operating principle for hydrogen fuel cells to establish forced circulation of the hydrogen mixture as an alternative to natural circulation(as is not utilized in conventional passive autocatalytic hydrogen recombiners currently used in nuclear power plants(NPPs)).The proposed concept of applying the physical operation principles of a PEHR based on a fuel cell simultaneously increases both productivity in terms of recombined hydrogen and the concentration threshold of flameless operation(the‘ignition’limit).Thus,it is possible to reliably ensure the hydrogen explosion safety of NPPs under all conditions,including beyond-design accidents.An experimental setup was assembled to test a laboratory sample of a membrane electrode assembly(MEA)at various hydrogen concentrations near the catalytic surfaces of the electrodes,and the corresponding current–voltage characteristics were recorded.The simplest MEA based on the Advent P1100W PBI membrane demonstrated stable performance(delivery of electrical power)over a wide range of hydrogen concentrations.展开更多
In this study,an amine-coordinated cobalt phthalocyanine(CoPc)-based anodic catalyst was fabricated by a facile process,to enhance the performance of hydrogen peroxide fuel cells(HPFCs) and enzymatic biofuel cells(EBC...In this study,an amine-coordinated cobalt phthalocyanine(CoPc)-based anodic catalyst was fabricated by a facile process,to enhance the performance of hydrogen peroxide fuel cells(HPFCs) and enzymatic biofuel cells(EBCs).For this purpose,polyethyleneimine(PEI) was added onto the reduced graphene oxide and CoPc composite(RGO/CoPc) to create abundant NH2 axial ligand groups,for anchoring the Co core within the CoPc.Owing to the PEI addition,the onset potential of the hydrogen peroxide oxidation reaction was shifted by 0.13 V in the negative direction(0.02 V) and the current density was improved by 1.92 times(1.297 mA cm^(-2)),compared to those for RGO/CoPc(0.15 V and 0.676 mA cm^(-2),respectively),due to the formation of donor-acceptor dyads and the prevention of CoPc from leaching out.The biocatalyst using glucose oxidase(GOx)([RGO/CoPc]/PEI/GOx) showed a better onset potential and catalytic activity(0.15 V and 318.7 μA cm^(-2)) than comparable structures,as well as significantly improved operational durability and long-term stability.This is also attributed to PEI,which created a favorable microenvironment for the enzyme.The maximum power densities(MPDs) and open-circuit voltages(OCVs) obtained for HPFCs and EBCs using the suggested catalyst were 105.2±1.3 μW cm^(-2)(0.317±0.003 V) and 25.4±0.9 μW cm^(-2)(0.283±0.007 V),respectively.This shows that the amine axial ligand effectively improves the performance of the actual driving HPFCs and EBCs.展开更多
Constructing electrocatalytic overall reaction technology to couple the electrosynthesis of adipic acid with energy-saving hydrogen production is of significant for sustainable energy systems.However,the development o...Constructing electrocatalytic overall reaction technology to couple the electrosynthesis of adipic acid with energy-saving hydrogen production is of significant for sustainable energy systems.However,the development of highly-active bifunctional electrocatalysts remains a challenge.Herein,3D hierarchical nickel-copper alloying arrays with dendritic morphology are manufactured by a simple electrodeposition process,standing for the excellent bifunctional electrocatalyst towards the co-production of adipic acid and H_(2)from cyclohexanone and water.The membrane-free flow electrolyzer of Cu_(0.81)Ni_(0.19)/NF shows the superior electrooxidation performance of ketone-alcohol(KA)oil with high faradaic efficiencies of over 90%for adipic acid and H_(2),robust stability over 200 h as well as a high yield of 0.6 mmol h^(-1) for adipic acid at 100 mA cm^(-2).In-situ spectroscopy indicates the Cu_(0.81)Ni_(0.19)alloy contributes to forming more active NiOOH species to involve in the conversion of cyclohexanone to adipic acid,while the proposed reaction pathway undergoes the 2-hydroxycyclohexanone and 2,7-oxepanedione intermediates.Moreover,the theoretical calculations confirm that the optimal electronic interaction,boosted reaction kinetics as well as improved adsorption free energy of reaction intermediates,synergistically endows Cu_(0.81)Ni_(0.19)alloy with superior bifunctional performance.展开更多
In efforts to overcome an foreseeable energy crisis predicated on limited oil and gas supplies, reserves; economic variations facing the world, and of course the environmental side effects of fossil fuels, an urgent n...In efforts to overcome an foreseeable energy crisis predicated on limited oil and gas supplies, reserves; economic variations facing the world, and of course the environmental side effects of fossil fuels, an urgent need for energy sources that provide sustainable, safe and economic supplies for the world is imperative. The current fossil fuel energy system must be improved to ensure a better and cleaner transportation future for the world. Despite the fact that the marine transportation sector consumes only 5% of global petroleum production; it is responsible for 15% of the world NOx and SOx emissions. These figures must be the engine that powers the scientific research worldwide to develop new solutions for a very old energy problem. In this paper, the most effective types of marine power plants were discussed. The history of the development of each type was presented first and the technical aspects were discussed second. Also, the fuel ceils as a new type of power plants used in marine sector were briefed to give a complete overview of the past, present and future of the marine power plants development. Based on the increased worldwide concerns regarding harmful emissions, many researchers have introduced solutions to this problem, including the adoption of new cleaner fuels. This paper was guided using the same trend and by implementing the hydrogen as fuel for marine internal combustion engine, gas turbines, and fuel cells.展开更多
Nitrogen doping of the carbon is an important method to improve the performance and durability of catalysts for proton exchange membrane fuel cells by platinum–nitrogen and carbon–nitrogen bonds. This study shows th...Nitrogen doping of the carbon is an important method to improve the performance and durability of catalysts for proton exchange membrane fuel cells by platinum–nitrogen and carbon–nitrogen bonds. This study shows that p-phenyl groups and graphitic N acting bridges linking platinum and the graphene/carbon black(the ratio graphene/carbon black = 2/3) hybrid support materials achieved the average size of platinum nanoparticles with(4.88 ± 1.79) nm. It improved the performance of the lower-temperature hydrogen fuel cell up to 0.934 W cm^(-2) at 0.60 V, which is 1.55 times greater than that of commercial Pt/C. Doping also enhanced the interaction between Pt and the support materials, and the resistance to corrosion, thus improving the durability of the low-temperature hydrogen fuel cell with a much lower decay of 10 mV at 0.80 A cm^(-2) after 30 k cycles of an in-situ accelerated stress test of catalyst degradation than that of 92 mV in Pt/C, which achieves the target of Department of Energy(<30 mV). Meanwhile,Pt/Nr EGO_(2)-CB_(3) remains 78% of initial power density at 1.5 A cm^(-2) after 5 k cycles of in-situ accelerated stress test of carbon corrosion, which is more stable than the power density of commercial Pt/C, keeping only 54% after accelerated stress test.展开更多
In the face of growing environmental pollution, developing a fuel-cell-driven shunting locomotive is a great challenge in China for environmental protection and energy saving, which combines the environmental advantag...In the face of growing environmental pollution, developing a fuel-cell-driven shunting locomotive is a great challenge in China for environmental protection and energy saving, which combines the environmental advantages of an electric locomotive with the lower infrastructure costs of a diesel-electric locomotive. In this paper, the investigation status and the development trend of the fuel-cell-driven shunting locomotive were introduced. Through innovation of the power system using fuel cells, an experiment prototype of a fuel-cell shunting locomotive was developed, which would reduce the effects on the environment of the existing locomotives. This was the first locomotive to use a proton exchange membrane fuel-cell （PEMFC） power plant in China. From October 2012, we started to test the fuel-cell power plant and further test runs on the test rail-line in Chengdu, Sichuan. The achieved encouraging results can provide fundamental data for the modification of the current individual fuel cell locomotives or further development of the fuel-cell hybrid ones in China.展开更多
Low activation materials have to be developed toward fusion demonstrationreactors. Ferritic steel, vanadium alloy and SiC/SiC composite are candidate materials of the firstwall, vacuum vessel and blanket components, r...Low activation materials have to be developed toward fusion demonstrationreactors. Ferritic steel, vanadium alloy and SiC/SiC composite are candidate materials of the firstwall, vacuum vessel and blanket components, respectively. Although changes of mechanical-thermalproperties owing to neutron irradiation have been investigated so far, there is little data for theplasma material interactions, such as fuel hydrogen retention and erosion. In the present study,deuterium retention and physical sputtering of low activation ferritic steel, F82H, wereinvestigated by using deuterium ion irradiation apparatus. After a ferritic steel sample wasirradiated by 1.7 keV D^+ ions, the weight loss was measured to obtain the physical sputteringyield. The sputtering yield was 0.04, comparable to that of stainless steel. In order to obtain theretained amount of deuterium, technique of thermal desorption spectroscopy (TDS) was employed to theirradiated sample. The retained deuterium desorbed at temperature ranging from 450 K to 700 K, inthe forms of DHO, D_2, D_2O and hydrocarbons. Hence, the deuterium retained can be reduced by bakingwith a relatively low temperature. The fluence dependence of retained amount of deuterium wasmeasured by changing the ion fluence. In the ferritic steel without mechanical polish, the retainedamount was large even when the fluence was low. In such a case, a large amount of deuterium wastrapped in the surface oxide layer containing O and C. When the fluence was large, the thickness ofsurface oxide layer was reduced by the ion sputtering, and then the retained amount in the oxidelayer decreased. In the case of a high fluence, the retained amount of deuterium became comparableto that of ferritic steel with mechanical polish or SS 316 L, and one order of magnitude smallerthan that of graphite. When the ferritic steel is used, it is required to remove the surface oxidelayer for reduction of fuel hydrogen retention. Ferritic steel sample was exposed to the environmentof JFT-2M tokamak in JAERI and after thatthe deuterium retention was examined. The result wasroughly the same as the case of deuterium ion irradiation experiment.展开更多
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 electrolyt...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.展开更多
文摘In the field of rail transit,the UK Department of Transport stated that it will realize a comprehensive transformation of UK railways by 2050,abandoning traditional diesel trains and upgrading them to new environmentally friendly trains.The current mainstream upgrade methods are electrification and hydrogen fuel cells.Comprehensive upgrades are costly,and choosing the optimal upgrade method for trams and mainline railways is critical.Without a sensitivity analysis,it is difficult for us to determine the influence relationship between each parameter and cost,resulting in a waste of cost when choosing a line reconstruction method.In addition,by analyzing the sensitivity of different parameters to the cost,the primary optimization direction can be determined to reduce the cost.Global higher-order sensitivity analysis enables quantification of parameter interactions,showing non-additive effects between parameters.This paper selects the main parameters that affect the retrofit cost and analyzes the retrofit cost of the two upgrade methods in the case of trams and mainline railways through local and global sensitivity analysis methods.The results of the analysis show that,given the current UK rail system,it is more economical to choose electric trams and hydrogen mainline trains.For trams,the speed at which the train travels has the greatest impact on the final cost.Through the sensitivity analysis,this paper provides an effective data reference for the current railway upgrading and reconstruction plan and provides a theoretical basis for the next step of train parameter optimization.
文摘Escalating apprehension about the harmful effects of widespread use of conventional fossil fuels in the marine field and in internal combustion engines in general, has led to a vast amount of efforts and the directing of large capital investment towards research and development of sustainable alternative energy sources. One of the most promising and abundant of these sources is hydrogen. Firstly, the use of current fossil fuels is. discussed focusing on the emissions and economic sides to emphasize the need for a new, cleaner and renewable fuel with particular reference to hydrogen as a suitable possible alternative. Hydrogen properties, production and storage methods are then reviewed along with its suitability from the economical point of view. Finally, a cost analysis for the use of hydrogen in internal combustion engines is carried out to illustrate the benefits of its use as a replacement for diesel. The outcome of this cost analysis shows that 98% of the capital expenditure is consumed by the equipment, and 68.3% of the total cost of the equipment is spent on the solar photovoltaic cells. The hydrogen plant is classified as a large investment project because of its high initial cost which is about 1 billion US$; but this is justified because hydrogen is produced in a totally green way. When hydrogen is used as a fuel, no harmful emissions are obtained.
基金This work was financially supported by China Petrochemical Corporation(ST 20006-1,ST 20006-2).
文摘Fuel cells are considered to be one of the ideal alternatives to traditional fossil energy conversion devices.Membrane electrodes are the core components in the hydrogen fuel cells.Our work reported the synthesis of the Pt/C catalysts with different Pt loading,and by changing the Nafion content,hot pressing temperature and hot pressing pressure,the catalyst coated membrane(CCM)spraying process was optimized.Moreover,the three-dimensional structure model of the single battery membrane electrode was studied quantitatively,and the porous membrane electrode with gradient distribution was fabricated under optimized processing conditions,with excellent electrical performance.
基金Open access funding provided by North-West University
文摘This paper presents the concept of a passive electrochemical hydrogen recombiner(PEHR).The reaction energy of the recombination of hydrogen and oxygen is used as a source of electrical energy according to the operating principle for hydrogen fuel cells to establish forced circulation of the hydrogen mixture as an alternative to natural circulation(as is not utilized in conventional passive autocatalytic hydrogen recombiners currently used in nuclear power plants(NPPs)).The proposed concept of applying the physical operation principles of a PEHR based on a fuel cell simultaneously increases both productivity in terms of recombined hydrogen and the concentration threshold of flameless operation(the‘ignition’limit).Thus,it is possible to reliably ensure the hydrogen explosion safety of NPPs under all conditions,including beyond-design accidents.An experimental setup was assembled to test a laboratory sample of a membrane electrode assembly(MEA)at various hydrogen concentrations near the catalytic surfaces of the electrodes,and the corresponding current–voltage characteristics were recorded.The simplest MEA based on the Advent P1100W PBI membrane demonstrated stable performance(delivery of electrical power)over a wide range of hydrogen concentrations.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(Nos.2017R1D1A1B03032033 and 2020R1C1C1010386)“Leaders in INdustry-university Cooperation+”project supported by the Ministry of Education and National Research Foundation of Korea。
文摘In this study,an amine-coordinated cobalt phthalocyanine(CoPc)-based anodic catalyst was fabricated by a facile process,to enhance the performance of hydrogen peroxide fuel cells(HPFCs) and enzymatic biofuel cells(EBCs).For this purpose,polyethyleneimine(PEI) was added onto the reduced graphene oxide and CoPc composite(RGO/CoPc) to create abundant NH2 axial ligand groups,for anchoring the Co core within the CoPc.Owing to the PEI addition,the onset potential of the hydrogen peroxide oxidation reaction was shifted by 0.13 V in the negative direction(0.02 V) and the current density was improved by 1.92 times(1.297 mA cm^(-2)),compared to those for RGO/CoPc(0.15 V and 0.676 mA cm^(-2),respectively),due to the formation of donor-acceptor dyads and the prevention of CoPc from leaching out.The biocatalyst using glucose oxidase(GOx)([RGO/CoPc]/PEI/GOx) showed a better onset potential and catalytic activity(0.15 V and 318.7 μA cm^(-2)) than comparable structures,as well as significantly improved operational durability and long-term stability.This is also attributed to PEI,which created a favorable microenvironment for the enzyme.The maximum power densities(MPDs) and open-circuit voltages(OCVs) obtained for HPFCs and EBCs using the suggested catalyst were 105.2±1.3 μW cm^(-2)(0.317±0.003 V) and 25.4±0.9 μW cm^(-2)(0.283±0.007 V),respectively.This shows that the amine axial ligand effectively improves the performance of the actual driving HPFCs and EBCs.
基金financially supported by the National Natural Science Foundation of China(22205205,22472151)the Zhejiang Provincial Natural Science Foundation of China(LQ22B030008)the Science Foundation of Zhejiang Sci-Tech University(ZSTU)under Grant No.21062337-Y.
文摘Constructing electrocatalytic overall reaction technology to couple the electrosynthesis of adipic acid with energy-saving hydrogen production is of significant for sustainable energy systems.However,the development of highly-active bifunctional electrocatalysts remains a challenge.Herein,3D hierarchical nickel-copper alloying arrays with dendritic morphology are manufactured by a simple electrodeposition process,standing for the excellent bifunctional electrocatalyst towards the co-production of adipic acid and H_(2)from cyclohexanone and water.The membrane-free flow electrolyzer of Cu_(0.81)Ni_(0.19)/NF shows the superior electrooxidation performance of ketone-alcohol(KA)oil with high faradaic efficiencies of over 90%for adipic acid and H_(2),robust stability over 200 h as well as a high yield of 0.6 mmol h^(-1) for adipic acid at 100 mA cm^(-2).In-situ spectroscopy indicates the Cu_(0.81)Ni_(0.19)alloy contributes to forming more active NiOOH species to involve in the conversion of cyclohexanone to adipic acid,while the proposed reaction pathway undergoes the 2-hydroxycyclohexanone and 2,7-oxepanedione intermediates.Moreover,the theoretical calculations confirm that the optimal electronic interaction,boosted reaction kinetics as well as improved adsorption free energy of reaction intermediates,synergistically endows Cu_(0.81)Ni_(0.19)alloy with superior bifunctional performance.
文摘In efforts to overcome an foreseeable energy crisis predicated on limited oil and gas supplies, reserves; economic variations facing the world, and of course the environmental side effects of fossil fuels, an urgent need for energy sources that provide sustainable, safe and economic supplies for the world is imperative. The current fossil fuel energy system must be improved to ensure a better and cleaner transportation future for the world. Despite the fact that the marine transportation sector consumes only 5% of global petroleum production; it is responsible for 15% of the world NOx and SOx emissions. These figures must be the engine that powers the scientific research worldwide to develop new solutions for a very old energy problem. In this paper, the most effective types of marine power plants were discussed. The history of the development of each type was presented first and the technical aspects were discussed second. Also, the fuel ceils as a new type of power plants used in marine sector were briefed to give a complete overview of the past, present and future of the marine power plants development. Based on the increased worldwide concerns regarding harmful emissions, many researchers have introduced solutions to this problem, including the adoption of new cleaner fuels. This paper was guided using the same trend and by implementing the hydrogen as fuel for marine internal combustion engine, gas turbines, and fuel cells.
基金supported by the Engineering and Physical Sciences Research Council (EPSRC) EP/P009050/1 and EP/S021531/1the Henry Royce Institute for Advanced Materials, funded through the EPSRC grants EP/R00661X/1, EP/S019367/1, EP/P025021/1 and EP/P025498/1funding from the European Commission H2020ERC Starter grant Evolu TEM (715502)。
文摘Nitrogen doping of the carbon is an important method to improve the performance and durability of catalysts for proton exchange membrane fuel cells by platinum–nitrogen and carbon–nitrogen bonds. This study shows that p-phenyl groups and graphitic N acting bridges linking platinum and the graphene/carbon black(the ratio graphene/carbon black = 2/3) hybrid support materials achieved the average size of platinum nanoparticles with(4.88 ± 1.79) nm. It improved the performance of the lower-temperature hydrogen fuel cell up to 0.934 W cm^(-2) at 0.60 V, which is 1.55 times greater than that of commercial Pt/C. Doping also enhanced the interaction between Pt and the support materials, and the resistance to corrosion, thus improving the durability of the low-temperature hydrogen fuel cell with a much lower decay of 10 mV at 0.80 A cm^(-2) after 30 k cycles of an in-situ accelerated stress test of catalyst degradation than that of 92 mV in Pt/C, which achieves the target of Department of Energy(<30 mV). Meanwhile,Pt/Nr EGO_(2)-CB_(3) remains 78% of initial power density at 1.5 A cm^(-2) after 5 k cycles of in-situ accelerated stress test of carbon corrosion, which is more stable than the power density of commercial Pt/C, keeping only 54% after accelerated stress test.
基金supported by the National Natural Science Foundation of China (51177138)the Specialized Research Fund for the Doctoral Program of Higher Education (20100184110015)+3 种基金the International Science and Technology Cooperation and Exchange Research Plan of Sichuan Province (2012HH0007)the Science and Technology Development Plan of Ministry of Railways (2012J012-D)the Fundamental Research Funds for the Central Universities (SWJTU11CX030)the Specialized Research Fund for the Doctoral Program of Higher Education (20120184120011)
文摘In the face of growing environmental pollution, developing a fuel-cell-driven shunting locomotive is a great challenge in China for environmental protection and energy saving, which combines the environmental advantages of an electric locomotive with the lower infrastructure costs of a diesel-electric locomotive. In this paper, the investigation status and the development trend of the fuel-cell-driven shunting locomotive were introduced. Through innovation of the power system using fuel cells, an experiment prototype of a fuel-cell shunting locomotive was developed, which would reduce the effects on the environment of the existing locomotives. This was the first locomotive to use a proton exchange membrane fuel-cell （PEMFC） power plant in China. From October 2012, we started to test the fuel-cell power plant and further test runs on the test rail-line in Chengdu, Sichuan. The achieved encouraging results can provide fundamental data for the modification of the current individual fuel cell locomotives or further development of the fuel-cell hybrid ones in China.
文摘Low activation materials have to be developed toward fusion demonstrationreactors. Ferritic steel, vanadium alloy and SiC/SiC composite are candidate materials of the firstwall, vacuum vessel and blanket components, respectively. Although changes of mechanical-thermalproperties owing to neutron irradiation have been investigated so far, there is little data for theplasma material interactions, such as fuel hydrogen retention and erosion. In the present study,deuterium retention and physical sputtering of low activation ferritic steel, F82H, wereinvestigated by using deuterium ion irradiation apparatus. After a ferritic steel sample wasirradiated by 1.7 keV D^+ ions, the weight loss was measured to obtain the physical sputteringyield. The sputtering yield was 0.04, comparable to that of stainless steel. In order to obtain theretained amount of deuterium, technique of thermal desorption spectroscopy (TDS) was employed to theirradiated sample. The retained deuterium desorbed at temperature ranging from 450 K to 700 K, inthe forms of DHO, D_2, D_2O and hydrocarbons. Hence, the deuterium retained can be reduced by bakingwith a relatively low temperature. The fluence dependence of retained amount of deuterium wasmeasured by changing the ion fluence. In the ferritic steel without mechanical polish, the retainedamount was large even when the fluence was low. In such a case, a large amount of deuterium wastrapped in the surface oxide layer containing O and C. When the fluence was large, the thickness ofsurface oxide layer was reduced by the ion sputtering, and then the retained amount in the oxidelayer decreased. In the case of a high fluence, the retained amount of deuterium became comparableto that of ferritic steel with mechanical polish or SS 316 L, and one order of magnitude smallerthan that of graphite. When the ferritic steel is used, it is required to remove the surface oxidelayer for reduction of fuel hydrogen retention. Ferritic steel sample was exposed to the environmentof JFT-2M tokamak in JAERI and after thatthe deuterium retention was examined. The result wasroughly the same as the case of deuterium ion irradiation experiment.
基金supported by the Ministry of Knowledge Economy (MKE, Korea) under the Global Collaborative R&D program supervised by the KIAT (N0000698)
文摘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.
