This future article discusses the new prospects and directions of CO_(2)conversion via the photo-electrocatalytic(PEC)route.The second(2nd)generation solar fuels and chemicals(SFs)are generated directly in PEC systems...This future article discusses the new prospects and directions of CO_(2)conversion via the photo-electrocatalytic(PEC)route.The second(2nd)generation solar fuels and chemicals(SFs)are generated directly in PEC systems via electrons/protons reactions without forming molecular H_(2)as an intermediate,overcoming the thermodynamics limitations and practical issues encountered for electro-fuels produced by multistep thermocatalytic processes(i.e.CO_(2)conversion with H_(2)coming from water electrolysis).A distributed and decentralized production of SFs requires very compact,highly integrated,and intensified technologies.Among the existing reactors of advanced design(based on artificial leaves or photosynthesis),the integrated photovoltaic plus electrocatalytic(PV-EC)device is the only system(demonstrated at large scale)to produce SFs with high solar-to-fuel(STF)efficiency.However,while the literature indicates STF efficiency as the main(and only)measure of process performance,we remark here the need to refer to productivity(in terms of current density)and make tests with reliable flow PEC systems(with electrodes of at least 5–10 cm^(2))to accelerate the scaling-up process.Using approaches that minimize downstream separation costs is also mandatory.Many limitations exist in PEC systems,but most can be overcome by proper electrode and cell engineering,thus going beyond the properties of the electrocatalysts.As examples of current developments,we present the progress of(i)artificial leaf/tree devices for green H_(2)distributed production and(ii)a PEC device producing the same chemicals at both cathode and anode parts without downstream operations for green solvent distributed production.Based on these developments,future directions,such as producing fertilizers and food components from the air,are outlined.The aim is to provide new ideas and research directions from a personal perspective.展开更多
Improving vehicle fuel consumption,performance and aerodynamic efficiency by drag reduction especially in heavy vehicles is one of the indispensable issues of automotive industry.In this work,the effects of adding app...Improving vehicle fuel consumption,performance and aerodynamic efficiency by drag reduction especially in heavy vehicles is one of the indispensable issues of automotive industry.In this work,the effects of adding append devices like deflector and cab vane corner on heavy commercial vehicle drag reduction were investigated.For this purpose,the vehicle body structure was modeled with various supplementary parts at the first stage.Then,computational fluid dynamic(CFD) analysis was utilized for each case to enhance the optimal aerodynamic structure at different longitudinal speeds for heavy commercial vehicles.The results show that the most effective supplementary part is deflector,and by adding this part,the drag coefficient is decreased considerably at an optimum angle.By adding two cab vane corners at both frontal edges of cab,a significant drag reduction is noticed.Back vanes and base flaps are simple plates which can be added at the top and side end of container and at the bottom with specific angle respectively to direct the flow and prevent the turbulence.Through the analysis of airflow and pressure distribution,the results reveal that the cab vane reduces fuel consumption and drag coefficient by up to 20 % receptively using proper deflector angle.Finally,by adding all supplementary parts at their optimized positions,41% drag reduction is obtained compared to the simple model.展开更多
“双碳”背景下,煤电清洁低碳发展是必然趋势。通过煤与生物质、污泥、生活垃圾等可再生燃料耦合掺烧发电,能显著降低CO_(2)排放量,是燃煤电厂实现碳中和、碳达峰的路径之一。燃煤掺烧可再生燃料发电后,烟气中非常规污染物(痕量元素、V...“双碳”背景下,煤电清洁低碳发展是必然趋势。通过煤与生物质、污泥、生活垃圾等可再生燃料耦合掺烧发电,能显著降低CO_(2)排放量,是燃煤电厂实现碳中和、碳达峰的路径之一。燃煤掺烧可再生燃料发电后,烟气中非常规污染物(痕量元素、VOCs等)种类及含量将增加,因此研究燃煤电厂现有的大气污染物控制装置(air pollution control devices,APCDs)的脱除能力,及未来可用于燃煤电厂的多污染物协同控制技术对于非常规污染物减排尤为必要。基于掺烧后烟气非常规污染物的排放特征,该文重点分析其在APCDs各环保设备中的迁移转化规律及净化效果,阐述为更高效控制非常规污染物的改进工艺的技术进展。进一步对污染物协同脱除资源化技术的发展现状、技术问题及工程应用进行探讨,其规模化发展仍要面临许多技术挑战。未来燃煤电厂可通过耦合可再生燃料发电、污染物的协同控制并联合CO_(2)捕集利用与封存技术,助力实现“减污降碳”目标。展开更多
A monolithic hybrid fuel cell (MHFC) with a novel configuration was proposed in an effort to improve the fuel cell performance during instantaneous power changes. A modified direct methanol fuel cell (DMFC) with a lay...A monolithic hybrid fuel cell (MHFC) with a novel configuration was proposed in an effort to improve the fuel cell performance during instantaneous power changes. A modified direct methanol fuel cell (DMFC) with a layer of hydrous ruthenium dioxide (RuO2·xH2O) sandwiched between the anode catalyst layer and membrane was used to demonstrate the principle of the MHFC. Experimental results indicate that the RuO2·xH2O layer is equivalent to a resistor-capacitor transmission line and functions similar to a capacitor in parallel with the anode electrode. The improvement in dynamic response of the MHFC was experimentally confirmed under step current change and square current pulse operating. The ionic conductivity of the RuO2·xH2O layer was also obtained.展开更多
The components required for artificial photosynthesis including light absorbers and catalysts are being developed at a rapid rate.In many cases,the anodic and cathodic reactions driven with these systems are optimized...The components required for artificial photosynthesis including light absorbers and catalysts are being developed at a rapid rate.In many cases,the anodic and cathodic reactions driven with these systems are optimized for significantly different pH conditions,raising the issue of how they can be made compatible.Recent work from our group has shown that large pH gradients can be maintained during electrolysis using BPM(bipolar membrane)and that electronic/ionic membranes can be used to couple the two half reactions without the use of external wiring and reducing the ohmic drop in the system.This study investigates the properties of composite BPMs designed for artificial photosynthetic devices that require half reactions to operate under different pH conditions.Details of performance as a function of the nature of the composites and methods of creating BPMs are detailed.展开更多
基金the EU for providing support to these activities through the EU projects DECADE(862030),EPOCH(101070976)and SCOPE(810182)。
文摘This future article discusses the new prospects and directions of CO_(2)conversion via the photo-electrocatalytic(PEC)route.The second(2nd)generation solar fuels and chemicals(SFs)are generated directly in PEC systems via electrons/protons reactions without forming molecular H_(2)as an intermediate,overcoming the thermodynamics limitations and practical issues encountered for electro-fuels produced by multistep thermocatalytic processes(i.e.CO_(2)conversion with H_(2)coming from water electrolysis).A distributed and decentralized production of SFs requires very compact,highly integrated,and intensified technologies.Among the existing reactors of advanced design(based on artificial leaves or photosynthesis),the integrated photovoltaic plus electrocatalytic(PV-EC)device is the only system(demonstrated at large scale)to produce SFs with high solar-to-fuel(STF)efficiency.However,while the literature indicates STF efficiency as the main(and only)measure of process performance,we remark here the need to refer to productivity(in terms of current density)and make tests with reliable flow PEC systems(with electrodes of at least 5–10 cm^(2))to accelerate the scaling-up process.Using approaches that minimize downstream separation costs is also mandatory.Many limitations exist in PEC systems,but most can be overcome by proper electrode and cell engineering,thus going beyond the properties of the electrocatalysts.As examples of current developments,we present the progress of(i)artificial leaf/tree devices for green H_(2)distributed production and(ii)a PEC device producing the same chemicals at both cathode and anode parts without downstream operations for green solvent distributed production.Based on these developments,future directions,such as producing fertilizers and food components from the air,are outlined.The aim is to provide new ideas and research directions from a personal perspective.
文摘Improving vehicle fuel consumption,performance and aerodynamic efficiency by drag reduction especially in heavy vehicles is one of the indispensable issues of automotive industry.In this work,the effects of adding append devices like deflector and cab vane corner on heavy commercial vehicle drag reduction were investigated.For this purpose,the vehicle body structure was modeled with various supplementary parts at the first stage.Then,computational fluid dynamic(CFD) analysis was utilized for each case to enhance the optimal aerodynamic structure at different longitudinal speeds for heavy commercial vehicles.The results show that the most effective supplementary part is deflector,and by adding this part,the drag coefficient is decreased considerably at an optimum angle.By adding two cab vane corners at both frontal edges of cab,a significant drag reduction is noticed.Back vanes and base flaps are simple plates which can be added at the top and side end of container and at the bottom with specific angle respectively to direct the flow and prevent the turbulence.Through the analysis of airflow and pressure distribution,the results reveal that the cab vane reduces fuel consumption and drag coefficient by up to 20 % receptively using proper deflector angle.Finally,by adding all supplementary parts at their optimized positions,41% drag reduction is obtained compared to the simple model.
文摘“双碳”背景下,煤电清洁低碳发展是必然趋势。通过煤与生物质、污泥、生活垃圾等可再生燃料耦合掺烧发电,能显著降低CO_(2)排放量,是燃煤电厂实现碳中和、碳达峰的路径之一。燃煤掺烧可再生燃料发电后,烟气中非常规污染物(痕量元素、VOCs等)种类及含量将增加,因此研究燃煤电厂现有的大气污染物控制装置(air pollution control devices,APCDs)的脱除能力,及未来可用于燃煤电厂的多污染物协同控制技术对于非常规污染物减排尤为必要。基于掺烧后烟气非常规污染物的排放特征,该文重点分析其在APCDs各环保设备中的迁移转化规律及净化效果,阐述为更高效控制非常规污染物的改进工艺的技术进展。进一步对污染物协同脱除资源化技术的发展现状、技术问题及工程应用进行探讨,其规模化发展仍要面临许多技术挑战。未来燃煤电厂可通过耦合可再生燃料发电、污染物的协同控制并联合CO_(2)捕集利用与封存技术,助力实现“减污降碳”目标。
文摘A monolithic hybrid fuel cell (MHFC) with a novel configuration was proposed in an effort to improve the fuel cell performance during instantaneous power changes. A modified direct methanol fuel cell (DMFC) with a layer of hydrous ruthenium dioxide (RuO2·xH2O) sandwiched between the anode catalyst layer and membrane was used to demonstrate the principle of the MHFC. Experimental results indicate that the RuO2·xH2O layer is equivalent to a resistor-capacitor transmission line and functions similar to a capacitor in parallel with the anode electrode. The improvement in dynamic response of the MHFC was experimentally confirmed under step current change and square current pulse operating. The ionic conductivity of the RuO2·xH2O layer was also obtained.
文摘The components required for artificial photosynthesis including light absorbers and catalysts are being developed at a rapid rate.In many cases,the anodic and cathodic reactions driven with these systems are optimized for significantly different pH conditions,raising the issue of how they can be made compatible.Recent work from our group has shown that large pH gradients can be maintained during electrolysis using BPM(bipolar membrane)and that electronic/ionic membranes can be used to couple the two half reactions without the use of external wiring and reducing the ohmic drop in the system.This study investigates the properties of composite BPMs designed for artificial photosynthetic devices that require half reactions to operate under different pH conditions.Details of performance as a function of the nature of the composites and methods of creating BPMs are detailed.
