Herein,ionomer-free amorphous iridium oxide(IrO_(x))thin electrodes are first developed as highly active anodes for proton exchange membrane electrolyzer cells(PEMECs)via low-cost,environmentally friendly,and easily s...Herein,ionomer-free amorphous iridium oxide(IrO_(x))thin electrodes are first developed as highly active anodes for proton exchange membrane electrolyzer cells(PEMECs)via low-cost,environmentally friendly,and easily scalable electrodeposition at room temperature.Combined with a Nafion 117 membrane,the IrO_(x)-integrated electrode with an ultralow loading of 0.075 mg cm^(-2)delivers a high cell efficiency of about 90%,achieving more than 96%catalyst savings and 42-fold higher catalyst utilization compared to commercial catalyst-coated membrane(2 mg cm^(-2)).Additionally,the IrO_(x)electrode demonstrates superior performance,higher catalyst utilization and significantly simplified fabrication with easy scalability compared with the most previously reported anodes.Notably,the remarkable performance could be mainly due to the amorphous phase property,sufficient Ir^(3+)content,and rich surface hydroxide groups in catalysts.Overall,due to the high activity,high cell efficiency,an economical,greatly simplified and easily scalable fabrication process,and ultrahigh material utilization,the IrO_(x)electrode shows great potential to be applied in industry and accelerates the commercialization of PEMECs and renewable energy evolution.展开更多
The development of catalytic materials for the recycling CO_(2) through a myriad of available processes is an attractive field,especially given the current climate change.While there is increasing publication in this ...The development of catalytic materials for the recycling CO_(2) through a myriad of available processes is an attractive field,especially given the current climate change.While there is increasing publication in this field,the reported catalysts rarely deviate from the traditionally supported metal nanoparticle morphology,with the most simplistic method of enhancement being the addition of more metals to an already complex composition.Encapsulated catalysts,especially yolk@shell catalysts with hollow voids,offer answers to the most prominent issues faced by this field,coking and sintering,and further potential for more advanced phenomena,for example,the confinement effect,to promote selectivity or offer greater protection against coking and sintering.This work serves to demonstrate the current position of catalyst development in the fields of thermal CO_(2) reforming and hydrogenation,summarizing the most recent work available and most common metals used for these reactions,and how yolk@shell catalysts can offer superior performance and survivability in thermal CO_(2) reforming and hydrogenation to the more traditional structure.Furthermore,this work will briefly demonstrate the bespoke nature and highly variable yolk@shell structure.Moreover,this review aims to illuminate the spatial confinement effect and how it enhances yolk@shell structured nanoreactors is presented.展开更多
The review is a comprehensive discussion of current research advances,commercial scale developments,challenges,and techno-eco nomics for the entire H_(2) value chain,including production,mainly focusing on sustainable...The review is a comprehensive discussion of current research advances,commercial scale developments,challenges,and techno-eco nomics for the entire H_(2) value chain,including production,mainly focusing on sustainable sources,storage,and transport.The challenges,advantages,and uses of H_(2) energy are included at length.Moreover,apart from the sustainable production approaches,the approaches and current developments for combating the carbon dioxide(CO_(2))emissions from existing H_(2) production facilities are highlighted in terms of ca rbon capture,utilization,and storage(CCUS).Concisely,the review discusses current material and recent technological adva ncements in developing pilot projects and large-scale establishments for viable and rapidly emerging sou rce-ba sed H_(2) productio n.Moreover,the review also aims to provide an in-depthdiscussion and explore current developments based on the advantages of H_(2) energy in terms of its utilization,based on its high energy density,and its ability to be used as a feedstock and fuel.On the other hand,the challenges of H_(2) are also elabo rated.Next,the role of CCUS in a carbon-neutral economy and value chain for minimization of emissions from existing facilities is thoroughly deliberated,and the recent commercial-scale implementation of CCUS technologies is highlighted.Extending the utilization and recycling of captured CO_(2) emissions along with H_(2) to produce e-fuels in terms of current advances is detailed in this review.Fu rthermore,the most applicable,efficient,a nd develo ping approaches are discussed for physical and chemical H_(2) storage,considering recent la rge-scale implementations of liquid carriers and liquid organic hydrogen carriers as storage options.Lastly,the review elaborates on recent insights into advances in H_(2) transport infrastructure,including compressed and liquid H_(2) delivery via roads,ships,pipelines,and flight cargo.The review gives precise insights into the recent scenario through an elaborated conclusion of each discussion topic separately and a discussion of future perspectives.The current review will help researchers to fully understand the ongoing research advancements and challenges in the H_(2) value chain for formulating new solutions for sustainable H_(2) production,alo ng with focusing on suitable approaches for its storage and tra nsport to make the production and utilization of H_(2) applicable on a large scale.展开更多
随着碳中和目标的推进,综合能源系统(integrated energy system,IES)以其多能耦合、能量梯级利用等优势,逐渐成为能源供应的重要发展方向。在具有差异化用能需求的多功能区IES之间实现协同规划与调度,对提高系统经济性、降低系统碳排放...随着碳中和目标的推进,综合能源系统(integrated energy system,IES)以其多能耦合、能量梯级利用等优势,逐渐成为能源供应的重要发展方向。在具有差异化用能需求的多功能区IES之间实现协同规划与调度,对提高系统经济性、降低系统碳排放有着重要作用。然而,由于碳捕集机组、多类型氢能利用设备等低碳元件的接入以及可再生能源发电的不断增加,随之而来的元件模型非凸性与系统内多类型不确定性对系统规划的影响亟需研究。对此,该文考虑了机组低碳改造和氢能多模式利用低碳特性,提出了一种针对多功能区综合能源系统的不确定性协同规划方法。首先,详细分析了多功能区供/用能特性与多能互补关系,构建了具有分区差异化特征的多功能区设备规划策略。其次,建立了低碳改造后的热电联产机组和氢能多模式利用设备的数学模型,并对其低碳特性进行了分析。基于此,为应对规划周期内系统低碳改造成本的不确定性和短期内可再生能源出力的不确定性,提出了一种混合长-短期不确定性的多功能区IES协同规划模型。通过基于二进制扩展的凸包线性化方法,对所提规划模型中的非线性约束进行凸化,并采用相应的迭代收缩求解算法实现模型的有效求解。最后,通过某实际多功能区IES算例进行仿真,结果验证了所提模型和所用算法的有效性。展开更多
在“双碳”目标驱动下,构建低碳、经济和灵活的能源利用体系至关重要。为此,提出一种考虑源荷双侧需求响应和氢能多元利用的综合能源系统(integrated energy system,IES)低碳优化调度模型。首先,在源侧热电联产(combined heat and power...在“双碳”目标驱动下,构建低碳、经济和灵活的能源利用体系至关重要。为此,提出一种考虑源荷双侧需求响应和氢能多元利用的综合能源系统(integrated energy system,IES)低碳优化调度模型。首先,在源侧热电联产(combined heat and power,CHP)机组中引入电锅炉(electric boiler,EB)和卡琳娜(Kalina)循环模型,解耦CHP“以热定电”和“以电定热”模式,构建CHP灵活输出模型;其次,在荷侧引入电、热需求响应模型,并与源侧CHP灵活输出模型协调优化,构建源荷双侧需求响应模型;最后,在模型中引入含制氢、用氢、燃气混氢和储氢组成的氢能多元利用模型,建立了电-热-气-氢IES低碳优化调度模型。算例仿真结果表明,所提模型不仅有效降低了系统经济成本和碳排放量,还提高了新能源的消纳能力,实现了IES低碳、经济和灵活运行。展开更多
In the hydrogen network with the minimum hydrogen utility flow rate,the pinch appears at the point with zero hydrogen surplus,while the hydrogen surpluses of all the other points are positive.In the hydrogen purity pr...In the hydrogen network with the minimum hydrogen utility flow rate,the pinch appears at the point with zero hydrogen surplus,while the hydrogen surpluses of all the other points are positive.In the hydrogen purity profiles,the pinch can only lie at the sink-tie-line intersecting the source purity profile.According to the alternative distribution of the negative and positive regions,the effect of the purification to the hydrogen surplus is analyzed.The results show that when the purification is applied,the pinch point will appear neither above the purification feed nor between the initial pinch point and the purification feed,no matter the purification feed lies above or below the initial pinch point.This is validated by two case studies.展开更多
Hydrogen production via solar water splitting is regarded as one of the most promising ways to utilize solar energy and has attracted more and more attention. Great progress has been made on photocatalytic water split...Hydrogen production via solar water splitting is regarded as one of the most promising ways to utilize solar energy and has attracted more and more attention. Great progress has been made on photocatalytic water splitting for hydrogen production in the past few years. This review summarizesthe very recent progress (mainly in the last 2–3 years) on three major types of solar hydrogenproduction systems: particulate photocatalysis (PC) systems, photoelectrochemical (PEC) systems,and photovoltaic‐photoelectrochemical (PV‐PEC) hybrid systems. The solar‐to‐hydrogen (STH)conversion efficiency of PC systems has recently exceeded 1.0% using a SrTiO3:La,Rh/Au/BiVO4:Mophotocatalyst, 2.5% for PEC water splitting on a tantalum nitride photoanode, and reached 22.4%for PV‐PEC water splitting using a multi‐junction GaInP/GaAs/Ge cell and Ni electrode hybrid system.The advantages and disadvantages of these systems for hydrogen production via solar watersplitting, especially for their potential demonstration and application in the future, are briefly describedand discussed. Finally, the challenges and opportunities for solar water splitting solutions are also forecasted.展开更多
Nanostructured catalyst-integrated electrodes with remarkably reduced catalyst loadings,high catalyst utilization and facile fabrication are urgently needed to enable cost-effective,green hydrogen production via proto...Nanostructured catalyst-integrated electrodes with remarkably reduced catalyst loadings,high catalyst utilization and facile fabrication are urgently needed to enable cost-effective,green hydrogen production via proton exchange membrane electrolyzer cells(PEMECs).Herein,benefitting from a thin seeding layer,bottom-up grown ultrathin Pt nanosheets(Pt-NSs)were first deposited on thin Ti substrates for PEMECs via a fast,template-and surfactant-free electrochemical growth process at room temperature,showing highly uniform Pt surface coverage with ultralow loadings and vertically well-aligned nanosheet morphologies.Combined with an anode-only Nafion 117 catalyst-coated membrane(CCM),the Pt-NS electrode with an ultralow loading of 0.015 mgPt cm−2 demonstrates superior cell performance to the commercial CCM(3.0 mgPt cm^(−2)),achieving 99.5%catalyst savings and more than 237-fold higher catalyst utilization.The remarkable performance with high catalyst utilization is mainly due to the vertically well-aligned ultrathin nanosheets with good surface coverage exposing abundant active sites for the electrochemical reaction.Overall,this study not only paves a new way for optimizing the catalyst uniformity and surface coverage with ultralow loadings but also provides new insights into nanostructured electrode design and facile fabrication for highly efficient and low-cost PEMECs and other energy storage/conversion devices.展开更多
基金the support from the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy (EERE) under the Hydrogen and Fuel Cell Technologies Office Awards DE-EE0008426 and DE-EE0008423National Energy Technology Laboratory under Award DEFE0011585.
文摘Herein,ionomer-free amorphous iridium oxide(IrO_(x))thin electrodes are first developed as highly active anodes for proton exchange membrane electrolyzer cells(PEMECs)via low-cost,environmentally friendly,and easily scalable electrodeposition at room temperature.Combined with a Nafion 117 membrane,the IrO_(x)-integrated electrode with an ultralow loading of 0.075 mg cm^(-2)delivers a high cell efficiency of about 90%,achieving more than 96%catalyst savings and 42-fold higher catalyst utilization compared to commercial catalyst-coated membrane(2 mg cm^(-2)).Additionally,the IrO_(x)electrode demonstrates superior performance,higher catalyst utilization and significantly simplified fabrication with easy scalability compared with the most previously reported anodes.Notably,the remarkable performance could be mainly due to the amorphous phase property,sufficient Ir^(3+)content,and rich surface hydroxide groups in catalysts.Overall,due to the high activity,high cell efficiency,an economical,greatly simplified and easily scalable fabrication process,and ultrahigh material utilization,the IrO_(x)electrode shows great potential to be applied in industry and accelerates the commercialization of PEMECs and renewable energy evolution.
基金Financial support was provided by the Chinese Academy of Sciences–The World Academy of Sciences(CAS-TWAS)president fellowship。
文摘The development of catalytic materials for the recycling CO_(2) through a myriad of available processes is an attractive field,especially given the current climate change.While there is increasing publication in this field,the reported catalysts rarely deviate from the traditionally supported metal nanoparticle morphology,with the most simplistic method of enhancement being the addition of more metals to an already complex composition.Encapsulated catalysts,especially yolk@shell catalysts with hollow voids,offer answers to the most prominent issues faced by this field,coking and sintering,and further potential for more advanced phenomena,for example,the confinement effect,to promote selectivity or offer greater protection against coking and sintering.This work serves to demonstrate the current position of catalyst development in the fields of thermal CO_(2) reforming and hydrogenation,summarizing the most recent work available and most common metals used for these reactions,and how yolk@shell catalysts can offer superior performance and survivability in thermal CO_(2) reforming and hydrogenation to the more traditional structure.Furthermore,this work will briefly demonstrate the bespoke nature and highly variable yolk@shell structure.Moreover,this review aims to illuminate the spatial confinement effect and how it enhances yolk@shell structured nanoreactors is presented.
基金part of a research project PIF Alfa HI initiative 726174Alfaisal University and its Office of Research&Innovation for their continuous support throughout this study。
文摘The review is a comprehensive discussion of current research advances,commercial scale developments,challenges,and techno-eco nomics for the entire H_(2) value chain,including production,mainly focusing on sustainable sources,storage,and transport.The challenges,advantages,and uses of H_(2) energy are included at length.Moreover,apart from the sustainable production approaches,the approaches and current developments for combating the carbon dioxide(CO_(2))emissions from existing H_(2) production facilities are highlighted in terms of ca rbon capture,utilization,and storage(CCUS).Concisely,the review discusses current material and recent technological adva ncements in developing pilot projects and large-scale establishments for viable and rapidly emerging sou rce-ba sed H_(2) productio n.Moreover,the review also aims to provide an in-depthdiscussion and explore current developments based on the advantages of H_(2) energy in terms of its utilization,based on its high energy density,and its ability to be used as a feedstock and fuel.On the other hand,the challenges of H_(2) are also elabo rated.Next,the role of CCUS in a carbon-neutral economy and value chain for minimization of emissions from existing facilities is thoroughly deliberated,and the recent commercial-scale implementation of CCUS technologies is highlighted.Extending the utilization and recycling of captured CO_(2) emissions along with H_(2) to produce e-fuels in terms of current advances is detailed in this review.Fu rthermore,the most applicable,efficient,a nd develo ping approaches are discussed for physical and chemical H_(2) storage,considering recent la rge-scale implementations of liquid carriers and liquid organic hydrogen carriers as storage options.Lastly,the review elaborates on recent insights into advances in H_(2) transport infrastructure,including compressed and liquid H_(2) delivery via roads,ships,pipelines,and flight cargo.The review gives precise insights into the recent scenario through an elaborated conclusion of each discussion topic separately and a discussion of future perspectives.The current review will help researchers to fully understand the ongoing research advancements and challenges in the H_(2) value chain for formulating new solutions for sustainable H_(2) production,alo ng with focusing on suitable approaches for its storage and tra nsport to make the production and utilization of H_(2) applicable on a large scale.
文摘随着碳中和目标的推进,综合能源系统(integrated energy system,IES)以其多能耦合、能量梯级利用等优势,逐渐成为能源供应的重要发展方向。在具有差异化用能需求的多功能区IES之间实现协同规划与调度,对提高系统经济性、降低系统碳排放有着重要作用。然而,由于碳捕集机组、多类型氢能利用设备等低碳元件的接入以及可再生能源发电的不断增加,随之而来的元件模型非凸性与系统内多类型不确定性对系统规划的影响亟需研究。对此,该文考虑了机组低碳改造和氢能多模式利用低碳特性,提出了一种针对多功能区综合能源系统的不确定性协同规划方法。首先,详细分析了多功能区供/用能特性与多能互补关系,构建了具有分区差异化特征的多功能区设备规划策略。其次,建立了低碳改造后的热电联产机组和氢能多模式利用设备的数学模型,并对其低碳特性进行了分析。基于此,为应对规划周期内系统低碳改造成本的不确定性和短期内可再生能源出力的不确定性,提出了一种混合长-短期不确定性的多功能区IES协同规划模型。通过基于二进制扩展的凸包线性化方法,对所提规划模型中的非线性约束进行凸化,并采用相应的迭代收缩求解算法实现模型的有效求解。最后,通过某实际多功能区IES算例进行仿真,结果验证了所提模型和所用算法的有效性。
文摘在“双碳”目标驱动下,构建低碳、经济和灵活的能源利用体系至关重要。为此,提出一种考虑源荷双侧需求响应和氢能多元利用的综合能源系统(integrated energy system,IES)低碳优化调度模型。首先,在源侧热电联产(combined heat and power,CHP)机组中引入电锅炉(electric boiler,EB)和卡琳娜(Kalina)循环模型,解耦CHP“以热定电”和“以电定热”模式,构建CHP灵活输出模型;其次,在荷侧引入电、热需求响应模型,并与源侧CHP灵活输出模型协调优化,构建源荷双侧需求响应模型;最后,在模型中引入含制氢、用氢、燃气混氢和储氢组成的氢能多元利用模型,建立了电-热-气-氢IES低碳优化调度模型。算例仿真结果表明,所提模型不仅有效降低了系统经济成本和碳排放量,还提高了新能源的消纳能力,实现了IES低碳、经济和灵活运行。
基金Supported by the State Key Development Program for Basic Research of China（2012CB720500） the National Natural Science Foundation of China（21276205,20936004） the State Key Laboratory of Heavy Oil Processing
文摘In the hydrogen network with the minimum hydrogen utility flow rate,the pinch appears at the point with zero hydrogen surplus,while the hydrogen surpluses of all the other points are positive.In the hydrogen purity profiles,the pinch can only lie at the sink-tie-line intersecting the source purity profile.According to the alternative distribution of the negative and positive regions,the effect of the purification to the hydrogen surplus is analyzed.The results show that when the purification is applied,the pinch point will appear neither above the purification feed nor between the initial pinch point and the purification feed,no matter the purification feed lies above or below the initial pinch point.This is validated by two case studies.
基金supported by the National Basic Research Program of the Ministry of Science and Technology (973 Program, 2014CB239400)the National Natural Science Foundation of China (21501236, 21673230)Youth Innovation Promotion Association of Chinese Academy of Sciences (2016167)~~
文摘Hydrogen production via solar water splitting is regarded as one of the most promising ways to utilize solar energy and has attracted more and more attention. Great progress has been made on photocatalytic water splitting for hydrogen production in the past few years. This review summarizesthe very recent progress (mainly in the last 2–3 years) on three major types of solar hydrogenproduction systems: particulate photocatalysis (PC) systems, photoelectrochemical (PEC) systems,and photovoltaic‐photoelectrochemical (PV‐PEC) hybrid systems. The solar‐to‐hydrogen (STH)conversion efficiency of PC systems has recently exceeded 1.0% using a SrTiO3:La,Rh/Au/BiVO4:Mophotocatalyst, 2.5% for PEC water splitting on a tantalum nitride photoanode, and reached 22.4%for PV‐PEC water splitting using a multi‐junction GaInP/GaAs/Ge cell and Ni electrode hybrid system.The advantages and disadvantages of these systems for hydrogen production via solar watersplitting, especially for their potential demonstration and application in the future, are briefly describedand discussed. Finally, the challenges and opportunities for solar water splitting solutions are also forecasted.
基金The authors greatly appreciate the support from the U.S.Department of Energy’s Office of Energy Efficiency and Renewable Energy(EERE)under the Hydrogen and Fuel Cell Technologies Office Awards DE-EE0008426 and DE-EE0008423National Energy Technology Laboratory under Award DEFE0011585.
文摘Nanostructured catalyst-integrated electrodes with remarkably reduced catalyst loadings,high catalyst utilization and facile fabrication are urgently needed to enable cost-effective,green hydrogen production via proton exchange membrane electrolyzer cells(PEMECs).Herein,benefitting from a thin seeding layer,bottom-up grown ultrathin Pt nanosheets(Pt-NSs)were first deposited on thin Ti substrates for PEMECs via a fast,template-and surfactant-free electrochemical growth process at room temperature,showing highly uniform Pt surface coverage with ultralow loadings and vertically well-aligned nanosheet morphologies.Combined with an anode-only Nafion 117 catalyst-coated membrane(CCM),the Pt-NS electrode with an ultralow loading of 0.015 mgPt cm−2 demonstrates superior cell performance to the commercial CCM(3.0 mgPt cm^(−2)),achieving 99.5%catalyst savings and more than 237-fold higher catalyst utilization.The remarkable performance with high catalyst utilization is mainly due to the vertically well-aligned ultrathin nanosheets with good surface coverage exposing abundant active sites for the electrochemical reaction.Overall,this study not only paves a new way for optimizing the catalyst uniformity and surface coverage with ultralow loadings but also provides new insights into nanostructured electrode design and facile fabrication for highly efficient and low-cost PEMECs and other energy storage/conversion devices.
