Developing hydrogen energy is a key strategic pillar for global climate change mitigation and accelerating the energy transition.Currently,major economies globally are elevating hydrogen industry planning to national ...Developing hydrogen energy is a key strategic pillar for global climate change mitigation and accelerating the energy transition.Currently,major economies globally are elevating hydrogen industry planning to national energy strategy status,and international energy companies have begun to focus on developing hydrogen businesses.This study systematically reviews the development prospects,application fields,and strategic significance of hydrogen,summarizes the current status of the global hydrogen industry,analyzes the current development characteristics of the hydrogen industry,and reviews the hydrogen strategies of international energy companies.Finally,from a strategic,comprehensive,precise,and forward-looking perspective,it is suggested that China’s Energy enterprises promote the high-quality development of the hydrogen industry by overcoming bottlenecks across the entire hydrogen industry value chain,jointly driving industrial development from both the technology supply and demand sides,defining key development fields based on their respective strengths,and actively participating in international hydrogen energy trade.展开更多
Widespread use of green hydrogen is a critical route to achieving a carbon-neutral society,but it cannot be accomplished without extensive hydrogen distribution.Hydrogen pipelines are the most energy-efficient approac...Widespread use of green hydrogen is a critical route to achieving a carbon-neutral society,but it cannot be accomplished without extensive hydrogen distribution.Hydrogen pipelines are the most energy-efficient approach to transporting hydrogen in areas with high,long-term demand for hydrogen.A well-known fact is that the properties of hydrogen differ from those of natural gas,which leads to significant variations in the pipeline transportation process.In addition,hydrogen can degrade the mechanical properties of steels,thereby affecting pipeline integrity.This situation has led to two inevitable key challenges in the current development of hydrogen-pipeline technology:economic viability and safety.Based on a review of the current state of hydrogen pipelines,including material compatibility with hydrogen,design methods,process operations,safety monitoring,and standards,this paper highlights key knowledge gaps in gaseous hydrogen pipelines.These gaps include the utilisation of high-strength materials for hydrogen pipelines,design of high-quality hydrogen pipelines,determination of hydrogen velocity,and repurposing of existing natural-gas pipelines.This review aims to identify the challenges in current hydrogen pipelines development and provide valuable suggestions for future research.展开更多
Dibenzyltoluene(DBT)is a prospective liquid organic hydrogen carrier(LOHC)with low cost and high theoretical hydrogen storage capacity(6.2 wt%).However,the wide application of DBT is severely restricted by expensive n...Dibenzyltoluene(DBT)is a prospective liquid organic hydrogen carrier(LOHC)with low cost and high theoretical hydrogen storage capacity(6.2 wt%).However,the wide application of DBT is severely restricted by expensive noble catalysts.In this work,a new Mg-based metal hydride hydrogenation catalyst,which is composed of MgH_(2),Mg_(2)NiH_(4) and LaH_(3) micro-nano-particles.展开更多
The bicarbonate-formate(HCO_(3)−–HCO_(2)−)interconversion provides a promising cycle for a conveniently accessible hydrogen storage system via reversible dehydrogenation and hydrogenation processes.Existing catalytic...The bicarbonate-formate(HCO_(3)−–HCO_(2)−)interconversion provides a promising cycle for a conveniently accessible hydrogen storage system via reversible dehydrogenation and hydrogenation processes.Existing catalytic systems often use organic solvents,tedious optimization as well as manipulation of pH values,solvent,pressure and various additives.Herein,we present an operational,robust,safe and cost-effective catalytic system for hydrogen storage and liberation.We have established a unique catalytic system with two different solid organometallic assemblies(NHC-Ru and NHC-Ir)that facilitate the reversible transformation between sodium formate and bicarbonate in aqueous solutions collaboratively and efficiently.Notably,the NHC-Ru catalyst is privileged for the hydrogenation of sodium bicarbonate,whereas the NHC-Ir component enables the dehydrogenation of sodium formate,all in a single reaction vessel.What sets this system apart is its simplicity.The H_(2)discharging and recharging is simply regulated by heating the mixture with or without H_(2).Remarkably,this process requires no extra additives or supplementary treatments.Moreover,the reversible hydrogen storage system is durable and can be reused for over 30 cycles without a discernible decline in activity and selectivity.The strategic paradigm in this study shows significant practical potential in hydrogen fuel cell applications.展开更多
Electrocatalytic nitrate reduction reaction(NitRR)utilizing water as a hydrogen source under ambient conditions represents a highly promising avenue for sustainable ammonia synthesis and environmental remediation.Howe...Electrocatalytic nitrate reduction reaction(NitRR)utilizing water as a hydrogen source under ambient conditions represents a highly promising avenue for sustainable ammonia synthesis and environmental remediation.However,achieving high efficiency and selectivity in NitRR is fundamentally challenged by the complex lifecycle management of active hydrogen derived from water splitting.This review provides a timely and comprehensive analysis centered on the pivotal role and meticulous regulation of active hydrogen throughout the NitRR process.We first elucidate the distinct functions and characteristics of various hydrogen species,followed by a survey of advanced characterization techniques crucial for monitoring the dynamics of active hydrogen.Critically,three core strategies were systematically dissected to modulate the active hydrogen lifecycle:accelerating water activation and dissociation,enhancing the directional transport of hydrogen species,and precisely tuning active hydrogen coupling pathways while suppressing parasitic hydrogen evolution.By consolidating current understanding from both catalyst design and reaction mechanism perspectives,this review offers a hydrogen-centric roadmap and highlights emerging opportunities for rationally engineering advanced NitRR systems.展开更多
Direct evidence of hydrogen-assisted crack nucleation and propagation associated with the δ phase in the selective laser melted GH4169 superalloy was obtained.The analysis of hydrogen trapping sites using thermal des...Direct evidence of hydrogen-assisted crack nucleation and propagation associated with the δ phase in the selective laser melted GH4169 superalloy was obtained.The analysis of hydrogen trapping sites using thermal desorption spectroscopy revealed that the δ phase exhibits strong hydrogen capture capability,with a hydrogen desorption activation energy of 35.45±2.51 kJ/mol.In addition,spatially resolved hydrogen mapping conducted by scanning Kelvin probe force microscopy and hydrogen microprint technique provided further evidence for the δ phase as a deep hydrogen trapping site.The atomic-scale characterization sufficiently reveals the deformation mechanism of the δ phase induced by dislocation accumulation.Hydrogen-promoted dislocation slip localization facilitates the formation of microvoid defects in the δ phase,which is the main reason for the δ phase fracture,and induces intergranular and transgranular cracks.展开更多
Medium-entropy alloys(MEAs)that exhibit transformation-induced plasticity(TRIP)from face-centered cubic(FCC)to body-centered cubic(BCC)are considered promising for liquid hydrogen environments due to their remarkable ...Medium-entropy alloys(MEAs)that exhibit transformation-induced plasticity(TRIP)from face-centered cubic(FCC)to body-centered cubic(BCC)are considered promising for liquid hydrogen environments due to their remarkable cryogenic strength.Nonetheless,studies on hydrogen embrittlement(HE)in BCC-TRIP MEAs have not been conducted,although the TRIP effect and consequent BCC martensite usually deteriorate HE susceptibility.In these alloys,initial as-quenched martensite alters hydrogen diffusion and trap behavior,and deformation-induced martensitic transformation(DIMT)provides preferred crack propagation sites,which critically affects HE susceptibility.Therefore,this study aims to investigate the HE behav-ior of BCC-TRIP MEAs by designing four V10 Cr_(10)Co_(30)Fe_(50-x)Ni_(x)(x=0,1,2,and 3 at%)MEAs,adjusting both the initial phase constituent and phase metastability.A decreased Ni content leads to a reduced fraction and mechanical stability of FCC,which in turn increases HE susceptibility,as determined through electro-chemical hydrogen pre-charging and slow-strain rate tests The permeation test and thermal desorption analysis reveal that the hydrogen diffusivity and content are affected by initial BCC fraction,interconnectivity of BCC,and refined FCC.As these initial phase constituents differ between the alloys with FCC-and BCC-dominant initial phase,microstructural factors affecting HE are unveiled discretely among these alloy groups by correlation of hydrogen-induced crack behavior with hydrogen diffusion and trap behavior.In alloys with an FCC-dominant initial phase,the initial BCC fraction and DIMT initiation rate emerge as critical factors,rather than the extent of DIMT.For BCC-dominant alloys,the primary contributor is an increase in the initial BCC fraction,rather than the extent or rate of DIMT.The unraveled roles of microstructural factors provide insights into designing HE-resistant BCC-TRIP MEAs.展开更多
Green hydrogen is the most promising option and a two in one remedy that resolve the problem of both energy crisis and environmental pollution.Wide band gap semiconductors(WBG)(E_(g)>2 eV)are the most prominent and...Green hydrogen is the most promising option and a two in one remedy that resolve the problem of both energy crisis and environmental pollution.Wide band gap semiconductors(WBG)(E_(g)>2 eV)are the most prominent and leading catalytic materials in both electro and photocatalytic water splitting(WSR);two sustainable methods of green hydrogen production.WBGs guarantee long life time of photo charge carriers and thereby surface availability of electrons and holes.Therefore,WBG(with appropriate VB-CB potential)along with small band gap materials or sensitizers can yield extraordinary photocatalytic system for hydrogen production under solar light.The factors such as,free energy of hydrogen adsorption(ΔGH^(*))close to zero,high electron mobility,great thermal as well as electro chemical stability and high tunability make WBG an interesting and excellent catalyst in electrolysis too.Taking into account the current relevance and future scope,the present review article comprehends different dimensions of WBG materials as an electro/photo catalyst for hydrogen evolution reaction.Herein WBG semiconductors are presented under various classes;viz.II-VI,III-V,III-VI,lanthanide oxides,transition metal based systems,carbonaceous materials and other systems such as SiC and MXenes.Catalytic properties of WBGs favorable for hydrogen production are then reviewed.A detailed analysis on relationship between band structure and activity(electro,photo and photo-electrochemical WSR)is performed.The challenges involved in these reactions as well as the direction of advancement in WBG based catalysis are also debated.By virtue of this article authors aims to guideline and promote the development of new WBG based electro/photocatalyst for HER and other applications.展开更多
The magnesium based metal hydrogen storage composite system Mg(NH_(2))_(2)-2LiH has a theoretical hydro-gen storage capacity of 5.6 wt.%and is a promising hydrogen storage material for vehicles.However,its application...The magnesium based metal hydrogen storage composite system Mg(NH_(2))_(2)-2LiH has a theoretical hydro-gen storage capacity of 5.6 wt.%and is a promising hydrogen storage material for vehicles.However,its application is limited due to serious thermodynamic and kinetic barriers.Introducing efficient catalysts is an effective method to improve the hydrogen storage performance of Mg(NH_(2))_(2)-2LiH.This article in-vestigates for the first time the use of nano rare earth oxide CeO_(2)(~44.5 nm)as an efficient modifier,achieving comprehensive regulation of the hydrogen storage performance of Mg(NH_(2))_(2)-2LiH composite system through oxygen vacancy driven catalysis.The modification mechanism of nano CeO_(2) is also sys-tematically studied using density functional theory(DFT)calculations and experimental results.Research has shown that the comprehensive hydrogen storage performance of the Mg(NH_(2))_(2)-2LiH-5 wt.%CeO_(2) composite system is optimal,with high hydrogen absorption and desorption kinetics and reversible per-formance.The initial hydrogen absorption and desorption temperatures of the composite system were significantly reduced from 110/130℃to 65/80℃,and the release of by-product ammonia was signifi-cantly inhibited.Under the conditions of 170℃/50 min and 180℃/100 min,4.37 wt.%of hydrogen can be rapidly absorbed and released.After 10 cycles of hydrogen release,the hydrogen cycle retention rate increased from 85%to nearly 100%.Further mechanistic studies have shown that the nano CeO_(2-x) gen-erated in situ during hydrogen evolution can effectively weaken the Mg-N and N-H bonds of Mg(NH_(2))_(2),exhibiting good catalytic effects.Meanwhile,oxygen vacancies provide a fast pathway for the diffusion of hydrogen atoms in the composite system.In addition,nano CeO_(2-x) can effectively inhibit the polycrys-talline transformation of the hydrogen evolving product Li_(2)MgN_(2)H_(2) in the system at high temperatures,reducing the difficulty of re-hydrogenation of the system.This study provides an innovative perspective for the efficient modification of magnesium based metal hydrogen storage composite materials using rare earth based catalysts,and also provides a reference for regulating the comprehensive hydrogen storage performance of hydrogen storage materials using rare earth catalysts with oxygen vacancies.展开更多
This review details the advancement in the development of V–Ti-based hydrogen storage materials for using in metal hydride(MH)tanks to supply hydrogen to fuel cells at relatively ambient temperatures and pressures.V...This review details the advancement in the development of V–Ti-based hydrogen storage materials for using in metal hydride(MH)tanks to supply hydrogen to fuel cells at relatively ambient temperatures and pressures.V–Tibased solid solution alloys are excellent hydrogen storage materials among many metal hydrides due to their high reversible hydrogen storage capacity which is over 2 wt%at ambient temperature.The preparation methods,structure characteristics,improvement methods of hydrogen storage performance,and attenuation mechanism are systematically summarized and discussed.The relationships between hydrogen storage properties and alloy compositions as well as phase structures are discussed emphatically.For large-scale applications on MH tanks,it is necessary to develop low-cost and high-performance V–Ti-based solid solution alloys with high reversible hydrogen storage capacity,good cyclic durability,and excellent activation performance.展开更多
Herein,we report the multi-metal atomic catalysts for solid-state dehydrogenation of MgH_(2).It aims to reveal the multi-element synergy in catalysts for solid-state hydrogen storage.The kinetic measurements and fitti...Herein,we report the multi-metal atomic catalysts for solid-state dehydrogenation of MgH_(2).It aims to reveal the multi-element synergy in catalysts for solid-state hydrogen storage.The kinetic measurements and fitting reveal two mechanisms:one shows a maximum rate at the early stage,such as V and Cr;the other needs a temperature-sensitive preparation time for its maximum rate,such as Ni.The combina-tion of two catalyst components demonstrates the best kinetics:V and Cr boost the initial dehydrogena-tion,and Ni benefits the further hydrogen transfer which alleviates the rate of decay.This work provides guidelines for the design of multi-element doped catalysts for MgH_(2) dehydrogenation.展开更多
The selective hydrogenation ofα,β-unsaturated aldehydes/ketones enables precise control over product structures and properties by regulating hydrogen transport pathways and bond cleavage sequences to selectively red...The selective hydrogenation ofα,β-unsaturated aldehydes/ketones enables precise control over product structures and properties by regulating hydrogen transport pathways and bond cleavage sequences to selectively reduce C=C or C=O bonds while preserving other functional groups within the molecule.This approach serves as a critical strategy for the directional synthesis of high-value molecules.However,achieving such selectivity remains challenging due to the thermodynamic equilibrium and kinetic competition between C=O and C=C bonds inα,β-unsaturated systems.Consequently,constructing precisely targeted catalytic systems is essential to overcome these limitations,offering both fundamental scientific significance and industrial application potential.Metal-organic frameworks(MOFs)and their derivatives have emerged as innovative platforms for designing such systems,owing to their programmable topology,tunable pore microenvironments,spatially controllable active sites,and modifiable electronic structures.This review systematically summarizes the research progress of MOF-based catalysts for selec-tive hydrogenation ofα,β-unsaturated aldehydes/ketones in the last decade,with emphasis on the design strategy,conformational relationship,and catalytic mechanism,aiming to provide new ideas for the design of targeted catalyt-ic systems for the selective hydrogenation ofα,β-unsaturated aldehydes/ketones.展开更多
The Caribbean presents a wide range of opportunities with varying potential to contribute to the Gross National Incomes of the countries.However,the tourism industry remains a key source of income but is vulnerable to...The Caribbean presents a wide range of opportunities with varying potential to contribute to the Gross National Incomes of the countries.However,the tourism industry remains a key source of income but is vulnerable to disasters and other upheavals.There are alternatives to sustainable growth such as the blue economy with the potential for hydrogen extraction from the Caribbean Sea,which can make a signi fiicant contribution.The Caribbean Transshipment Triangle boasts signi fiicant port infrastructure that plays a crucial role in transporting goods and has the potential to become hydrogen hubs.The aim of this research is to examine the potential for countries in the region to develop this industry.A quantitative methodology was employed to examine the correlation between renewable energy and economic growth among six major transshipment countries in the Caribbean transshipment triangle,from 2010 to 2020.The study employed the Pearson correlation coef fiicient to analyze the data collected from these countries.The fiindings indicated that the Dominican Republic and Panama had the highest correlation between renewable energy and economic growth.Speci fiically,Jamaica,Panama,and the Dominican Republic demonstrated a moderate to high correlation between Renewable Power Capacity(RPC)and GDP.Consequently,investing in port infrastructure to facilitate hydrogen production,storage,distribution,and export could have positive effects on these economies.These fiindings are of interest to governments,managers,professionals,policymakers,and investors in the power generation sector.The research supports visions of a resilient blue economy and addresses sustainable development concerns in the Caribbean region.展开更多
Combined with the hydrogen pre-charging and tensile testing methods,the effect of charged hydrogen content on the microstructure and mechanical behavior of an as-forged Ti–6Al–4V alloy was investigated.After perform...Combined with the hydrogen pre-charging and tensile testing methods,the effect of charged hydrogen content on the microstructure and mechanical behavior of an as-forged Ti–6Al–4V alloy was investigated.After performing hydrogen charging for 2,4,6,8 and 10 h at a constant cathodic current density value of 75 mA/cm^(2) in a corrosion medium of 3.5 wt.%NaCl solution,the hydrogen contents in the charged samples increased gradually from 73×10^(−4) to 230×10^(−4) wt.%.When the hydrogen content was less than 190×10^(−4) wt.%,the charged hydrogen atoms were present as the solute atoms in the matrix,resulting in the enhanced tensile strength due to the solid solution strengthening of hydrogen atoms.Moreover,the reduced axial ratio c/a for α-Ti matrix due to the hydrogen dissolution was beneficial to improving the ductility of the hydrogenated samples.The critical hydrogen content for simultaneously improving the ductility and strength is determined to be 99×10^(−4)wt.%.When the hydrogen content was 230×10^(−4)wt.%,a small number of δ-TiHx hydrides and micro cracks formed in the localized areas of α-Ti matrix,resulting in the simultaneous decrease of ductility and strength.展开更多
ZnO-based catalysts have been widely used in hydrogenation reactions,but less attention has been paid to the electrocatalytic hydrogenation process on ZnO electrodes.In this work,the preparation of hydrogen species an...ZnO-based catalysts have been widely used in hydrogenation reactions,but less attention has been paid to the electrocatalytic hydrogenation process on ZnO electrodes.In this work,the preparation of hydrogen species and the associ-ated reduction properties under electrochemi-cal processes in aqueous solutions have been in-vestigated on ZnO and Au/ZnO electrodes.The measurements of cyclic voltammetry(CV),X-ray diffraction,and electron paramagnetic resonance(EPR)confirm the formation of hydro-gen species on the interstitial sites(Hi)or on the oxygen vacancy sites(H_(O)).The hydrogena-tion reaction of p-nitrophenol(pNP)at 40μmol/L occurs on both ZnO and Au/ZnO elec-trodes,and the hydrogenation reduction performance of Au/ZnO electrode is better than that of ZnO electrode.CVs show H_(O)species is much more reactive with pNP than Hi species.Compared with the ZnO electrode,the presence of Au on ZnO promotes the formation of H_(O)species and improves the electro-reduction performance to pNP.These results help us to un-derstand the reaction processes related to the electrochemical hydrogenation on ZnO and Au/ZnO surfaces and shed new light on the design of new catalytic hydrogenation systems.展开更多
Methane,the primary constituent of natural gas,shale gas,and flammable ice,serves as a crucial carbon-based energy source and chemical feedstock.Traditional gas reserves are universally acknowledged as limited and non...Methane,the primary constituent of natural gas,shale gas,and flammable ice,serves as a crucial carbon-based energy source and chemical feedstock.Traditional gas reserves are universally acknowledged as limited and non-renewable resources over an extended timespan stretching from decades to millennia.Biomethane,with its unique renewable properties,showcases remarkable development potential and presents a compelling supplement and even alternative for fossil fuel.Although catalytic hydrothermal processes appear as promising valorization routes to transfer biomass to sustainable methane,the safety and supply source of high-pressure hydrogen remain key factors restricting the widespread application.Herein,a catalytic approach without an external hydrogen source was developed to transform waste biomass resources into CH_(4)under the Ni-Mo catalyst.The total carbon yield of gas products reached up to 92.2%,of which the yield of methane and C2–C4 hydrocarbons were 44.9%and 3.0%,respectively.And it’s calculated that approximately 343.6 liters of CH_(4)could potentially be generated from 1 kilogram of raw biomass.Ni-based catalysts exhibited the robust activity in cleaving C–C and C–O bonds.And the introduction of an appropriate amount of molybdenum significantly enhanced catalytic performance of reforming and subsequent methanation reaction,likely due to the high adsorption capacity of highly dispersed Ni-Mo catalysts for carbon monoxide and hydrogen molecules,facilitating the methanation reaction.The pathway of catalytic methane production might be inferred that CO,H_(2)and a large number of oxygen-containing intermediates were formed via decarbonylation,dehydrogenation,and retro-aldol condensation reaction under hydrothermal condition.These intermediates then underwent the reforming reaction to generate H_(2)and CO_(2),ultimately forming CH_(4)through the methanation reaction.展开更多
Hydrogen embrittlement(HE)in 2 GPa-grade press-hardened steel(PHS)has posed a great risk to its lightweighting application in automotive crash-resistant components.While conventional slow strain rate tensile tests sho...Hydrogen embrittlement(HE)in 2 GPa-grade press-hardened steel(PHS)has posed a great risk to its lightweighting application in automotive crash-resistant components.While conventional slow strain rate tensile tests show that the precharged hydrogen concentration of 3.5 wppm induces a severe loss in strength and ductility,the high strain rate tests conducted at 1–103 s−1 that simulate the crash condition demonstrate no loss in strength and a minimal loss in ductility.Such strain rate dependency cannot be exclusively explained via hydrogen diffusion and redistribution to susceptible prior austenite grain boundaries,as the tensile testing of precharged samples with jumping strain rates offers a sufficient redistribution period at slow-strain-rate loading,but does not necessarily lead to a high level of HE afterwards.Detailed fractography analysis acknowledges that hydrogen-induced microcracks nucleated within early deformation stages are directly responsible for the high HE susceptibility of all test conditions.A phase-field simulation comprising 2 GPa-grade PHS's microstructure features and the hydrogen diffusion under tested loading conditions is applied.The calculation reveals that the hydrogen redistribution behavior is spatially confined to the crack tip areas but to a much greater extent.It thus facilitates continuous crack growth following the main crack with minimal plastic deformation and avoids branching to form secondary cracks.The combined experiments and modeling highlight the vital role of microcracks in the HE performance of 2 GPa-grade PHS,upon which the safety factor of HE in high-strength martensitic steels shall be established.展开更多
Integrating the photovoltaic/thermal(PV/T)system in green hydrogen production is an improvement in sustainable energy technologies.In PV/T systems,solar energy is converted into electricity and thermal energy simultan...Integrating the photovoltaic/thermal(PV/T)system in green hydrogen production is an improvement in sustainable energy technologies.In PV/T systems,solar energy is converted into electricity and thermal energy simultaneously using hot water or air together with electricity.This dual use saves a significant amount of energy and officially fights greenhouse gases.Different cooling techniques have been proposed in the literature for improving the overall performance of the PV/T systems;employing different types of agents including nanofluids and phase change materials.Hydrogen is the lightest and most abundant element in the universe and has later turned into a flexible energy carrier for transportation and other industrial applications.Issues,including the processes of Hydrogen manufacturing,preservation as well as some risks act as barriers.This paper provides an analysis of several recent publications on the efficiency of using PV/T technology in the process of green hydrogen production and indicates the potential for its increased efficiency as compared to conventional systems that rely on fossil fuels.Due to the effective integration of solar energy,the PV/T system can play an important role in the reduction of the levelized cost of hydrogen(LCOH)and hence play an important part in reducing the economic calculations of the decarbonized energy system.展开更多
Metallic single-atom catalysts(SACs)have demonstrated high activity and potential in enhancing the hydrogen storage properties of MgH_(2).However,previous reports primarily focus on supported SACs,which often suffer f...Metallic single-atom catalysts(SACs)have demonstrated high activity and potential in enhancing the hydrogen storage properties of MgH_(2).However,previous reports primarily focus on supported SACs,which often suffer from insufficient co ntact between single-atom active sites and hydrogen storage materials.In this study,the precursor Mo(CO)_(6)is uniformly dispersed on the surface of MgH_(2)via impregnation adsorption,leading to the formation of alloy-type Mo single atoms after hydrogenation/dehydrogenation activation.This alloy structure enables zero-distance contact between catalytic sites and the hydrogen storage material,facilitating electron exchange and hydrogen transfer between the Mo sites and MgH_(2).The MgH_(2)loaded with Mo single atoms(Mo_(1)-MgH_(2))exhibits excellent hydrogen absorption and desorption properties,with the initial hydrogen release temperature lowered from 323 to 218℃.At 250℃,Mo_(1)-MgH_(2)absorbs over 6.77 wt% of hydrogen within 1 min and releases over 5.85 wt% within 4 h.During 10 cycles of hydrogenation and dehydrogenation reactions,Mo_(1)-MgH_(2)maintains nearly 100% capacity and shows stable kinetics.This work provides new insights into the design and fabrication of catalysts for hydrogen storage materials.展开更多
Although MgH_(2)is widely deemed to be the most promising solid-state hydrogen storage materials for the medium-high temperature fuelcell applications expected in the near future,the high-temperature desorption and sl...Although MgH_(2)is widely deemed to be the most promising solid-state hydrogen storage materials for the medium-high temperature fuelcell applications expected in the near future,the high-temperature desorption and sluggish hydrogen absorption/desorption kinetics are the major challenges for its applications.Herein,reduced graphene oxide/patronite nanoparticle composite(rGO@VS_(4))is successfully synthesized using an ionic liquid(IL)-assisted hydrothermal method,and superior catalytic effects originated from the rGO@VS_(4)composite precursor towards the hydrogen storage reaction of MgH_(2)are systematically investigated.The VS_(4)reacts with MgH_(2)leads to the in-situ formed and uniformly scattered of metallic V and MgS during both ball-milling and the initial hydrogen desorption,and the synergic catalytic effect of metallic V and MgS facilitates the improved hydrogen desorption of MgH_(2).The MgH_(2)-15 wt%rGO@VS_(4)composite starts releasing hydrogen at 180℃and peaks at 220℃,which is 145℃and 128℃lower than that of the Pristine MgH_(2),respectively.The energy required for H_(2)desorption from MgH_(2)is decreased to 63.8 kJ mol^(-1),58.9 kJ mol^(-1)lower than that of the Pristine MgH_(2).Furthermore,the MgH_(2)-15 wt%rGO@VS_(4)composite shows excellent cycling stability,of which reversible hydrogen capacity can stabilize at about 5.9 wt%with capacity retention of 98.2%at 300℃for 100 cycles.This study provides a deeper insight into metallic V and MgS to enhance the hydrogen desorption of solid-state hydrogen storage materials and also offers a perspective for the construction of high-activity catalysts for solid-state hydrogen storage materials.展开更多
文摘Developing hydrogen energy is a key strategic pillar for global climate change mitigation and accelerating the energy transition.Currently,major economies globally are elevating hydrogen industry planning to national energy strategy status,and international energy companies have begun to focus on developing hydrogen businesses.This study systematically reviews the development prospects,application fields,and strategic significance of hydrogen,summarizes the current status of the global hydrogen industry,analyzes the current development characteristics of the hydrogen industry,and reviews the hydrogen strategies of international energy companies.Finally,from a strategic,comprehensive,precise,and forward-looking perspective,it is suggested that China’s Energy enterprises promote the high-quality development of the hydrogen industry by overcoming bottlenecks across the entire hydrogen industry value chain,jointly driving industrial development from both the technology supply and demand sides,defining key development fields based on their respective strengths,and actively participating in international hydrogen energy trade.
基金supported by the National Key Research and Development Program of China(No.2022YFB4003400)the Key Research and Development Program of Zhejiang Province of China(No.2023C01225)the State Key Laboratory of Clean Energy Utilization,China。
文摘Widespread use of green hydrogen is a critical route to achieving a carbon-neutral society,but it cannot be accomplished without extensive hydrogen distribution.Hydrogen pipelines are the most energy-efficient approach to transporting hydrogen in areas with high,long-term demand for hydrogen.A well-known fact is that the properties of hydrogen differ from those of natural gas,which leads to significant variations in the pipeline transportation process.In addition,hydrogen can degrade the mechanical properties of steels,thereby affecting pipeline integrity.This situation has led to two inevitable key challenges in the current development of hydrogen-pipeline technology:economic viability and safety.Based on a review of the current state of hydrogen pipelines,including material compatibility with hydrogen,design methods,process operations,safety monitoring,and standards,this paper highlights key knowledge gaps in gaseous hydrogen pipelines.These gaps include the utilisation of high-strength materials for hydrogen pipelines,design of high-quality hydrogen pipelines,determination of hydrogen velocity,and repurposing of existing natural-gas pipelines.This review aims to identify the challenges in current hydrogen pipelines development and provide valuable suggestions for future research.
基金supported by the National Key R&D Program of China(No.2023YFB3809100)the Youth Fund Project of Grinm(No.SKHT10422023060280).
文摘Dibenzyltoluene(DBT)is a prospective liquid organic hydrogen carrier(LOHC)with low cost and high theoretical hydrogen storage capacity(6.2 wt%).However,the wide application of DBT is severely restricted by expensive noble catalysts.In this work,a new Mg-based metal hydride hydrogenation catalyst,which is composed of MgH_(2),Mg_(2)NiH_(4) and LaH_(3) micro-nano-particles.
基金Financial support from the National Natural Science Foundation of China(No.22271060)。
文摘The bicarbonate-formate(HCO_(3)−–HCO_(2)−)interconversion provides a promising cycle for a conveniently accessible hydrogen storage system via reversible dehydrogenation and hydrogenation processes.Existing catalytic systems often use organic solvents,tedious optimization as well as manipulation of pH values,solvent,pressure and various additives.Herein,we present an operational,robust,safe and cost-effective catalytic system for hydrogen storage and liberation.We have established a unique catalytic system with two different solid organometallic assemblies(NHC-Ru and NHC-Ir)that facilitate the reversible transformation between sodium formate and bicarbonate in aqueous solutions collaboratively and efficiently.Notably,the NHC-Ru catalyst is privileged for the hydrogenation of sodium bicarbonate,whereas the NHC-Ir component enables the dehydrogenation of sodium formate,all in a single reaction vessel.What sets this system apart is its simplicity.The H_(2)discharging and recharging is simply regulated by heating the mixture with or without H_(2).Remarkably,this process requires no extra additives or supplementary treatments.Moreover,the reversible hydrogen storage system is durable and can be reused for over 30 cycles without a discernible decline in activity and selectivity.The strategic paradigm in this study shows significant practical potential in hydrogen fuel cell applications.
基金financially supported by the National Natural Science Foundation of China(22179035)the Science Fund for Distinguished Young Scholars of Heilongjiang Province(JQ2022B001)the Fundamental Research Funds for the Universities of Heilongjiang Province of China(2023-KYYWF1440)。
文摘Electrocatalytic nitrate reduction reaction(NitRR)utilizing water as a hydrogen source under ambient conditions represents a highly promising avenue for sustainable ammonia synthesis and environmental remediation.However,achieving high efficiency and selectivity in NitRR is fundamentally challenged by the complex lifecycle management of active hydrogen derived from water splitting.This review provides a timely and comprehensive analysis centered on the pivotal role and meticulous regulation of active hydrogen throughout the NitRR process.We first elucidate the distinct functions and characteristics of various hydrogen species,followed by a survey of advanced characterization techniques crucial for monitoring the dynamics of active hydrogen.Critically,three core strategies were systematically dissected to modulate the active hydrogen lifecycle:accelerating water activation and dissociation,enhancing the directional transport of hydrogen species,and precisely tuning active hydrogen coupling pathways while suppressing parasitic hydrogen evolution.By consolidating current understanding from both catalyst design and reaction mechanism perspectives,this review offers a hydrogen-centric roadmap and highlights emerging opportunities for rationally engineering advanced NitRR systems.
基金financially supported by the National Natural Science Foundation of China(Nos.U21A2044 and 52201060)Science Center for Gas Turbine Project(No.P2022-B-Ⅳ-008-001)China Postdoctoral Science Foundation(Nos.BX20220035 and 2022M710347).
文摘Direct evidence of hydrogen-assisted crack nucleation and propagation associated with the δ phase in the selective laser melted GH4169 superalloy was obtained.The analysis of hydrogen trapping sites using thermal desorption spectroscopy revealed that the δ phase exhibits strong hydrogen capture capability,with a hydrogen desorption activation energy of 35.45±2.51 kJ/mol.In addition,spatially resolved hydrogen mapping conducted by scanning Kelvin probe force microscopy and hydrogen microprint technique provided further evidence for the δ phase as a deep hydrogen trapping site.The atomic-scale characterization sufficiently reveals the deformation mechanism of the δ phase induced by dislocation accumulation.Hydrogen-promoted dislocation slip localization facilitates the formation of microvoid defects in the δ phase,which is the main reason for the δ phase fracture,and induces intergranular and transgranular cracks.
基金supported by the Korea Institute for Advance-ment of Technology(KIAT)grant funded by the Korea Government(MOTIE)(HRD Program for Industrial Innovation)(No.P0023676)the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(Nos.NRF-2022R1A5A1030054 and RS-2023-00281508).
文摘Medium-entropy alloys(MEAs)that exhibit transformation-induced plasticity(TRIP)from face-centered cubic(FCC)to body-centered cubic(BCC)are considered promising for liquid hydrogen environments due to their remarkable cryogenic strength.Nonetheless,studies on hydrogen embrittlement(HE)in BCC-TRIP MEAs have not been conducted,although the TRIP effect and consequent BCC martensite usually deteriorate HE susceptibility.In these alloys,initial as-quenched martensite alters hydrogen diffusion and trap behavior,and deformation-induced martensitic transformation(DIMT)provides preferred crack propagation sites,which critically affects HE susceptibility.Therefore,this study aims to investigate the HE behav-ior of BCC-TRIP MEAs by designing four V10 Cr_(10)Co_(30)Fe_(50-x)Ni_(x)(x=0,1,2,and 3 at%)MEAs,adjusting both the initial phase constituent and phase metastability.A decreased Ni content leads to a reduced fraction and mechanical stability of FCC,which in turn increases HE susceptibility,as determined through electro-chemical hydrogen pre-charging and slow-strain rate tests The permeation test and thermal desorption analysis reveal that the hydrogen diffusivity and content are affected by initial BCC fraction,interconnectivity of BCC,and refined FCC.As these initial phase constituents differ between the alloys with FCC-and BCC-dominant initial phase,microstructural factors affecting HE are unveiled discretely among these alloy groups by correlation of hydrogen-induced crack behavior with hydrogen diffusion and trap behavior.In alloys with an FCC-dominant initial phase,the initial BCC fraction and DIMT initiation rate emerge as critical factors,rather than the extent of DIMT.For BCC-dominant alloys,the primary contributor is an increase in the initial BCC fraction,rather than the extent or rate of DIMT.The unraveled roles of microstructural factors provide insights into designing HE-resistant BCC-TRIP MEAs.
文摘Green hydrogen is the most promising option and a two in one remedy that resolve the problem of both energy crisis and environmental pollution.Wide band gap semiconductors(WBG)(E_(g)>2 eV)are the most prominent and leading catalytic materials in both electro and photocatalytic water splitting(WSR);two sustainable methods of green hydrogen production.WBGs guarantee long life time of photo charge carriers and thereby surface availability of electrons and holes.Therefore,WBG(with appropriate VB-CB potential)along with small band gap materials or sensitizers can yield extraordinary photocatalytic system for hydrogen production under solar light.The factors such as,free energy of hydrogen adsorption(ΔGH^(*))close to zero,high electron mobility,great thermal as well as electro chemical stability and high tunability make WBG an interesting and excellent catalyst in electrolysis too.Taking into account the current relevance and future scope,the present review article comprehends different dimensions of WBG materials as an electro/photo catalyst for hydrogen evolution reaction.Herein WBG semiconductors are presented under various classes;viz.II-VI,III-V,III-VI,lanthanide oxides,transition metal based systems,carbonaceous materials and other systems such as SiC and MXenes.Catalytic properties of WBGs favorable for hydrogen production are then reviewed.A detailed analysis on relationship between band structure and activity(electro,photo and photo-electrochemical WSR)is performed.The challenges involved in these reactions as well as the direction of advancement in WBG based catalysis are also debated.By virtue of this article authors aims to guideline and promote the development of new WBG based electro/photocatalyst for HER and other applications.
基金supported by the National Natural Science Foundation of China(Nos.51971199 and 51771171).
文摘The magnesium based metal hydrogen storage composite system Mg(NH_(2))_(2)-2LiH has a theoretical hydro-gen storage capacity of 5.6 wt.%and is a promising hydrogen storage material for vehicles.However,its application is limited due to serious thermodynamic and kinetic barriers.Introducing efficient catalysts is an effective method to improve the hydrogen storage performance of Mg(NH_(2))_(2)-2LiH.This article in-vestigates for the first time the use of nano rare earth oxide CeO_(2)(~44.5 nm)as an efficient modifier,achieving comprehensive regulation of the hydrogen storage performance of Mg(NH_(2))_(2)-2LiH composite system through oxygen vacancy driven catalysis.The modification mechanism of nano CeO_(2) is also sys-tematically studied using density functional theory(DFT)calculations and experimental results.Research has shown that the comprehensive hydrogen storage performance of the Mg(NH_(2))_(2)-2LiH-5 wt.%CeO_(2) composite system is optimal,with high hydrogen absorption and desorption kinetics and reversible per-formance.The initial hydrogen absorption and desorption temperatures of the composite system were significantly reduced from 110/130℃to 65/80℃,and the release of by-product ammonia was signifi-cantly inhibited.Under the conditions of 170℃/50 min and 180℃/100 min,4.37 wt.%of hydrogen can be rapidly absorbed and released.After 10 cycles of hydrogen release,the hydrogen cycle retention rate increased from 85%to nearly 100%.Further mechanistic studies have shown that the nano CeO_(2-x) gen-erated in situ during hydrogen evolution can effectively weaken the Mg-N and N-H bonds of Mg(NH_(2))_(2),exhibiting good catalytic effects.Meanwhile,oxygen vacancies provide a fast pathway for the diffusion of hydrogen atoms in the composite system.In addition,nano CeO_(2-x) can effectively inhibit the polycrys-talline transformation of the hydrogen evolving product Li_(2)MgN_(2)H_(2) in the system at high temperatures,reducing the difficulty of re-hydrogenation of the system.This study provides an innovative perspective for the efficient modification of magnesium based metal hydrogen storage composite materials using rare earth based catalysts,and also provides a reference for regulating the comprehensive hydrogen storage performance of hydrogen storage materials using rare earth catalysts with oxygen vacancies.
基金supported by the Key-Area Research and Development Program of Guangdong Province(No.2023B0909060001)the National Natural Science Foundation of China(No.52271213)。
文摘This review details the advancement in the development of V–Ti-based hydrogen storage materials for using in metal hydride(MH)tanks to supply hydrogen to fuel cells at relatively ambient temperatures and pressures.V–Tibased solid solution alloys are excellent hydrogen storage materials among many metal hydrides due to their high reversible hydrogen storage capacity which is over 2 wt%at ambient temperature.The preparation methods,structure characteristics,improvement methods of hydrogen storage performance,and attenuation mechanism are systematically summarized and discussed.The relationships between hydrogen storage properties and alloy compositions as well as phase structures are discussed emphatically.For large-scale applications on MH tanks,it is necessary to develop low-cost and high-performance V–Ti-based solid solution alloys with high reversible hydrogen storage capacity,good cyclic durability,and excellent activation performance.
基金Yijing Wang acknowledges the funding support of the National Key Research and Development Program of China(No.2021YFB4000604)the National Natural Science Foundation of China(No.52271220)+6 种基金the Higher Education Discipline Innovation Project(No.B12015)“the Fundamental Research Funds for the Central Universities”Huaiyu Shao acknowledges the funding support of the Multi-Year Research Grant(MYRG)from the University of Macao(No.MYRG2022-00105-IAPME)the Joint Scientific Research Project Funding by the National Natural Science Foundation of China and the Macao Science and Technology Development Fund(No.0090/2022/AFJ)the Macao Science and Technology Development Fund(FDCT)for funding No.006/2022/ALC of the Macao Centre for Research and Development in Advanced Materials(No.2022-2024)the Natural Science Foundation of Guangdong Province(Grant No.2023A1515010765)the Shenzhen-Hong Kong-Macao Science and Technology Innovation Project(Category C).
文摘Herein,we report the multi-metal atomic catalysts for solid-state dehydrogenation of MgH_(2).It aims to reveal the multi-element synergy in catalysts for solid-state hydrogen storage.The kinetic measurements and fitting reveal two mechanisms:one shows a maximum rate at the early stage,such as V and Cr;the other needs a temperature-sensitive preparation time for its maximum rate,such as Ni.The combina-tion of two catalyst components demonstrates the best kinetics:V and Cr boost the initial dehydrogena-tion,and Ni benefits the further hydrogen transfer which alleviates the rate of decay.This work provides guidelines for the design of multi-element doped catalysts for MgH_(2) dehydrogenation.
文摘The selective hydrogenation ofα,β-unsaturated aldehydes/ketones enables precise control over product structures and properties by regulating hydrogen transport pathways and bond cleavage sequences to selectively reduce C=C or C=O bonds while preserving other functional groups within the molecule.This approach serves as a critical strategy for the directional synthesis of high-value molecules.However,achieving such selectivity remains challenging due to the thermodynamic equilibrium and kinetic competition between C=O and C=C bonds inα,β-unsaturated systems.Consequently,constructing precisely targeted catalytic systems is essential to overcome these limitations,offering both fundamental scientific significance and industrial application potential.Metal-organic frameworks(MOFs)and their derivatives have emerged as innovative platforms for designing such systems,owing to their programmable topology,tunable pore microenvironments,spatially controllable active sites,and modifiable electronic structures.This review systematically summarizes the research progress of MOF-based catalysts for selec-tive hydrogenation ofα,β-unsaturated aldehydes/ketones in the last decade,with emphasis on the design strategy,conformational relationship,and catalytic mechanism,aiming to provide new ideas for the design of targeted catalyt-ic systems for the selective hydrogenation ofα,β-unsaturated aldehydes/ketones.
文摘The Caribbean presents a wide range of opportunities with varying potential to contribute to the Gross National Incomes of the countries.However,the tourism industry remains a key source of income but is vulnerable to disasters and other upheavals.There are alternatives to sustainable growth such as the blue economy with the potential for hydrogen extraction from the Caribbean Sea,which can make a signi fiicant contribution.The Caribbean Transshipment Triangle boasts signi fiicant port infrastructure that plays a crucial role in transporting goods and has the potential to become hydrogen hubs.The aim of this research is to examine the potential for countries in the region to develop this industry.A quantitative methodology was employed to examine the correlation between renewable energy and economic growth among six major transshipment countries in the Caribbean transshipment triangle,from 2010 to 2020.The study employed the Pearson correlation coef fiicient to analyze the data collected from these countries.The fiindings indicated that the Dominican Republic and Panama had the highest correlation between renewable energy and economic growth.Speci fiically,Jamaica,Panama,and the Dominican Republic demonstrated a moderate to high correlation between Renewable Power Capacity(RPC)and GDP.Consequently,investing in port infrastructure to facilitate hydrogen production,storage,distribution,and export could have positive effects on these economies.These fiindings are of interest to governments,managers,professionals,policymakers,and investors in the power generation sector.The research supports visions of a resilient blue economy and addresses sustainable development concerns in the Caribbean region.
基金supported by the National Natural Science Foundation of China(Grant Nos.51871211,U21A2049,52071220,51701129 and 51971054)Liaoning Province’s project of“Revitalizing Liaoning Talents”(XLYC1907062)+5 种基金the Doctor Startup Fund of Natural Science Foundation Program of Liaoning Province(No.2019-BS-200)Liaoning BaiQianWan Talents Program,the Domain Foundation of Equipment Advance Research of 13th Five-Year Plan(61409220118)National Key Research and Development Program of China(Grant Nos.2017YFB0702001 and 2016YFB0301105)the Innovation Fund of Institute of Metal Research(IMR),Chinese Academy of Sciences(CAS)the National Basic Research Program of China(973 Program)(Grant No.2013CB632205)the Fundamental Research Fund for the Central Universities(Grant No.N2009006).
文摘Combined with the hydrogen pre-charging and tensile testing methods,the effect of charged hydrogen content on the microstructure and mechanical behavior of an as-forged Ti–6Al–4V alloy was investigated.After performing hydrogen charging for 2,4,6,8 and 10 h at a constant cathodic current density value of 75 mA/cm^(2) in a corrosion medium of 3.5 wt.%NaCl solution,the hydrogen contents in the charged samples increased gradually from 73×10^(−4) to 230×10^(−4) wt.%.When the hydrogen content was less than 190×10^(−4) wt.%,the charged hydrogen atoms were present as the solute atoms in the matrix,resulting in the enhanced tensile strength due to the solid solution strengthening of hydrogen atoms.Moreover,the reduced axial ratio c/a for α-Ti matrix due to the hydrogen dissolution was beneficial to improving the ductility of the hydrogenated samples.The critical hydrogen content for simultaneously improving the ductility and strength is determined to be 99×10^(−4)wt.%.When the hydrogen content was 230×10^(−4)wt.%,a small number of δ-TiHx hydrides and micro cracks formed in the localized areas of α-Ti matrix,resulting in the simultaneous decrease of ductility and strength.
基金supported by the National Key Re-search and Development Program of China(No.2021YFA1500403)the National Natural Science Foundation of China(No.21773047 and No.U1832180)partially carried out at the USTC Center for Micro and Nanoscale Research and Fabrication.
文摘ZnO-based catalysts have been widely used in hydrogenation reactions,but less attention has been paid to the electrocatalytic hydrogenation process on ZnO electrodes.In this work,the preparation of hydrogen species and the associ-ated reduction properties under electrochemi-cal processes in aqueous solutions have been in-vestigated on ZnO and Au/ZnO electrodes.The measurements of cyclic voltammetry(CV),X-ray diffraction,and electron paramagnetic resonance(EPR)confirm the formation of hydro-gen species on the interstitial sites(Hi)or on the oxygen vacancy sites(H_(O)).The hydrogena-tion reaction of p-nitrophenol(pNP)at 40μmol/L occurs on both ZnO and Au/ZnO elec-trodes,and the hydrogenation reduction performance of Au/ZnO electrode is better than that of ZnO electrode.CVs show H_(O)species is much more reactive with pNP than Hi species.Compared with the ZnO electrode,the presence of Au on ZnO promotes the formation of H_(O)species and improves the electro-reduction performance to pNP.These results help us to un-derstand the reaction processes related to the electrochemical hydrogenation on ZnO and Au/ZnO surfaces and shed new light on the design of new catalytic hydrogenation systems.
文摘Methane,the primary constituent of natural gas,shale gas,and flammable ice,serves as a crucial carbon-based energy source and chemical feedstock.Traditional gas reserves are universally acknowledged as limited and non-renewable resources over an extended timespan stretching from decades to millennia.Biomethane,with its unique renewable properties,showcases remarkable development potential and presents a compelling supplement and even alternative for fossil fuel.Although catalytic hydrothermal processes appear as promising valorization routes to transfer biomass to sustainable methane,the safety and supply source of high-pressure hydrogen remain key factors restricting the widespread application.Herein,a catalytic approach without an external hydrogen source was developed to transform waste biomass resources into CH_(4)under the Ni-Mo catalyst.The total carbon yield of gas products reached up to 92.2%,of which the yield of methane and C2–C4 hydrocarbons were 44.9%and 3.0%,respectively.And it’s calculated that approximately 343.6 liters of CH_(4)could potentially be generated from 1 kilogram of raw biomass.Ni-based catalysts exhibited the robust activity in cleaving C–C and C–O bonds.And the introduction of an appropriate amount of molybdenum significantly enhanced catalytic performance of reforming and subsequent methanation reaction,likely due to the high adsorption capacity of highly dispersed Ni-Mo catalysts for carbon monoxide and hydrogen molecules,facilitating the methanation reaction.The pathway of catalytic methane production might be inferred that CO,H_(2)and a large number of oxygen-containing intermediates were formed via decarbonylation,dehydrogenation,and retro-aldol condensation reaction under hydrothermal condition.These intermediates then underwent the reforming reaction to generate H_(2)and CO_(2),ultimately forming CH_(4)through the methanation reaction.
基金support from the National Natural Science Foundation of China(No.52130102)the National Key Research and Development Program of China(No.2019YFA0209900)+5 种基金the Research Grants Council of Hong Kong(No.R7066–18)the Guangzhou Municipal Science and Technology Project(No.202007020007)the Guangdong Basic and Applied Basic Research Foundation of China(No.2020B1515130007)Lunhua He and Mingxin Huang acknowledge the support from the International Partnership Program of the Chinese Academy of Sciences(No.113111KYSB20190029)the key program of the Chinese Academy of Sciences(CAS)China Spallation Neutron Source(CSNS)is acknowledged for supporting neutron diffraction experiments using the General Purpose Powder Diffractometer(GPPD).
文摘Hydrogen embrittlement(HE)in 2 GPa-grade press-hardened steel(PHS)has posed a great risk to its lightweighting application in automotive crash-resistant components.While conventional slow strain rate tensile tests show that the precharged hydrogen concentration of 3.5 wppm induces a severe loss in strength and ductility,the high strain rate tests conducted at 1–103 s−1 that simulate the crash condition demonstrate no loss in strength and a minimal loss in ductility.Such strain rate dependency cannot be exclusively explained via hydrogen diffusion and redistribution to susceptible prior austenite grain boundaries,as the tensile testing of precharged samples with jumping strain rates offers a sufficient redistribution period at slow-strain-rate loading,but does not necessarily lead to a high level of HE afterwards.Detailed fractography analysis acknowledges that hydrogen-induced microcracks nucleated within early deformation stages are directly responsible for the high HE susceptibility of all test conditions.A phase-field simulation comprising 2 GPa-grade PHS's microstructure features and the hydrogen diffusion under tested loading conditions is applied.The calculation reveals that the hydrogen redistribution behavior is spatially confined to the crack tip areas but to a much greater extent.It thus facilitates continuous crack growth following the main crack with minimal plastic deformation and avoids branching to form secondary cracks.The combined experiments and modeling highlight the vital role of microcracks in the HE performance of 2 GPa-grade PHS,upon which the safety factor of HE in high-strength martensitic steels shall be established.
基金funding support from Arabian Gulf University to cover any necessary publication fees.
文摘Integrating the photovoltaic/thermal(PV/T)system in green hydrogen production is an improvement in sustainable energy technologies.In PV/T systems,solar energy is converted into electricity and thermal energy simultaneously using hot water or air together with electricity.This dual use saves a significant amount of energy and officially fights greenhouse gases.Different cooling techniques have been proposed in the literature for improving the overall performance of the PV/T systems;employing different types of agents including nanofluids and phase change materials.Hydrogen is the lightest and most abundant element in the universe and has later turned into a flexible energy carrier for transportation and other industrial applications.Issues,including the processes of Hydrogen manufacturing,preservation as well as some risks act as barriers.This paper provides an analysis of several recent publications on the efficiency of using PV/T technology in the process of green hydrogen production and indicates the potential for its increased efficiency as compared to conventional systems that rely on fossil fuels.Due to the effective integration of solar energy,the PV/T system can play an important role in the reduction of the levelized cost of hydrogen(LCOH)and hence play an important part in reducing the economic calculations of the decarbonized energy system.
基金supported by the Science and Technology Foundation of China Electric Power Research Institute(Development of high-energy-density alloy solid hydrogen storage materials,DG8323-002)。
文摘Metallic single-atom catalysts(SACs)have demonstrated high activity and potential in enhancing the hydrogen storage properties of MgH_(2).However,previous reports primarily focus on supported SACs,which often suffer from insufficient co ntact between single-atom active sites and hydrogen storage materials.In this study,the precursor Mo(CO)_(6)is uniformly dispersed on the surface of MgH_(2)via impregnation adsorption,leading to the formation of alloy-type Mo single atoms after hydrogenation/dehydrogenation activation.This alloy structure enables zero-distance contact between catalytic sites and the hydrogen storage material,facilitating electron exchange and hydrogen transfer between the Mo sites and MgH_(2).The MgH_(2)loaded with Mo single atoms(Mo_(1)-MgH_(2))exhibits excellent hydrogen absorption and desorption properties,with the initial hydrogen release temperature lowered from 323 to 218℃.At 250℃,Mo_(1)-MgH_(2)absorbs over 6.77 wt% of hydrogen within 1 min and releases over 5.85 wt% within 4 h.During 10 cycles of hydrogenation and dehydrogenation reactions,Mo_(1)-MgH_(2)maintains nearly 100% capacity and shows stable kinetics.This work provides new insights into the design and fabrication of catalysts for hydrogen storage materials.
基金supported by the National Key Research and Development Program of China(2022YFB3803801)National Natural Science Foundation of China(Grant No.52201275,52301287,52307250)+1 种基金Two-chain integration key project of Shaanxi Province(Grant No.2021LLRH-09)Young Talent Fund of Association for Science and Technology in Shaanxi,China(No.20220456).
文摘Although MgH_(2)is widely deemed to be the most promising solid-state hydrogen storage materials for the medium-high temperature fuelcell applications expected in the near future,the high-temperature desorption and sluggish hydrogen absorption/desorption kinetics are the major challenges for its applications.Herein,reduced graphene oxide/patronite nanoparticle composite(rGO@VS_(4))is successfully synthesized using an ionic liquid(IL)-assisted hydrothermal method,and superior catalytic effects originated from the rGO@VS_(4)composite precursor towards the hydrogen storage reaction of MgH_(2)are systematically investigated.The VS_(4)reacts with MgH_(2)leads to the in-situ formed and uniformly scattered of metallic V and MgS during both ball-milling and the initial hydrogen desorption,and the synergic catalytic effect of metallic V and MgS facilitates the improved hydrogen desorption of MgH_(2).The MgH_(2)-15 wt%rGO@VS_(4)composite starts releasing hydrogen at 180℃and peaks at 220℃,which is 145℃and 128℃lower than that of the Pristine MgH_(2),respectively.The energy required for H_(2)desorption from MgH_(2)is decreased to 63.8 kJ mol^(-1),58.9 kJ mol^(-1)lower than that of the Pristine MgH_(2).Furthermore,the MgH_(2)-15 wt%rGO@VS_(4)composite shows excellent cycling stability,of which reversible hydrogen capacity can stabilize at about 5.9 wt%with capacity retention of 98.2%at 300℃for 100 cycles.This study provides a deeper insight into metallic V and MgS to enhance the hydrogen desorption of solid-state hydrogen storage materials and also offers a perspective for the construction of high-activity catalysts for solid-state hydrogen storage materials.
