查看更多>>摘要：The transition towards sustainable and clean energy systems has become a significant concern in the modern world.Hydrogen has the potential to meet the growing energy demands while addressing greenhouse gas emissions.However,one major obstacle in utilizing hydrogen as a fuel is the lack of efficient and cost-effective storage methods.In this regard,liquid organic hydrogen carriers(LOHCs)offer several advantages,including high hydrogen storage capacity,improved safety compared to traditional storage methods,and the ability to transport hydrogen using existing liquid fuels'infrastructure.This review summarizes advancements in the development of LOHC systems for hydrogen storage,with a focus on the latest and innovative systems such as those based on dehydrogenative coupling reactions,renewable LOHCs from lignocellulosic biomass,and the development of LOHCs from plastic waste recycling.In addition to the material aspect,this contribution also discusses various applications of LOHCs in the broader context of the hydrogen economy,including a recently proposed concept of mixed gas hydrogenation of LOHCs for realizing hydrogen purification and storage in a single process step.By highlighting the main advantages and challenges of each LOHC system and providing future directions in the development of efficient LOHC systems,this review aims to contribute to an extensive under-standing and advancement of LOHCs in the evolving hydrogen-based economy.
查看更多>>摘要：In multi-component alloy steels,the interplay of chemical interactions among elements and variations in atomic radius often results in element segregation towards defects,markedly influencing the macroscopic material properties.Despite many recent studies reporting defect-dependent element segregation in steel,a comprehensive overview is still lacking.In this work,element segregation at various defects and their influence on steel per-formance are examined.It specifically delves into the influences of element segregation at dislocation,grain boundary,phase boundary,and precipitate phase interface on the mechanical performance of steel.For each type of crystal defect-induced element segregation,this review discusses the crystallographic structure,segregated microstructure,element segregation distribution,and the corresponding influence of element segregation on the mechanical performance of steel.Finally,this review extensively explores the scientific issues and challenges of element segregation research in steel.It provides valuable insights into the behavior of element segregation in steel and inspires new research directions in other multi-component alloys.
查看更多>>摘要：This paper primarily examines the utilization and obstacles of AI in the domain of chemistry.Machine learning facilitates the advancement of chemical research at every level through the use of AI.AI has significantly contributed to enhancing the efficiency of chemical experiments and manufacturing,as well as reducing costs,throughout the many phases of chemical study,application,and production.Its impact is particularly notable in the development of new materials and the discovery of drugs.Nevertheless,the implementation of AI in the domain of chemistry encounters numerous obstacles,including inadequate data quality,limited model inter-pretability,and data privacy concerns.To address these issues,it is imperative for the scientific and technological community to foster multidisciplinary collaboration,develop a more comprehensive and practical AI framework,and investigate more secure data security technologies.In the future,as AI continues to advance,the relationship between AI and chemical research will become more dependable and intimate.This will lead to increased effi-ciency,safety,and cost-effectiveness in chemical research,ushering in a new era in the field of chemistry.
查看更多>>摘要：The element segregation accompanying the creep process has been shown to significantly affect the deformation resistance of the superalloys.However,the processing and mechanism of element segregation are still unclear.This paper investigated the concentration evolution of a model Co-9Al-9W(at.％)alloy during 900 ℃/275 MPa using developed ternary elastoplastic phase-field model coupled with CALPHAD method and crystal plasticity model.The results of simulation show that co-depletion of Al and W element occurs in γ'precipitate and in y side at γ/γ'interface,and this depletion is gradually increasing with the accumulation of plastic strain.From the perspective of changes of driving force of element diffusion,it is found that these segregation phenomena are attributed to the high elastic potential caused by the large local plastic strain.In addition,the effects of these segregations on creep property are also predicted.The current research provides a new method for exploring the mechanism of element diffusion.
查看更多>>摘要：High entropy alloys(HEAs),known for their synergistic orbital interactions among multiple elements,have been recognized as promising electrocatalysts for enhancing the sluggish kinetics of oxygen evolution reaction(OER).Despite their potential,the facile and rapid preparation of HEA nanoparticles(NPs)with high electrocatalytic activity remains challenging.Here,we report an ultrafast synthesis of noble-metal-free FeCoMnCuAl HEA NPs loaded on conductive carbon fiber networks using a Joule heating strategy.The prepared HEA NPs exhibited a face-centered cubic(FCC)structure with an average size of approximately 25 nm.Synchrotron X-ray absorption fine structure(XAFS)and X-ray photoelectron spectroscopy(XPS)studies were performed to investigate the atomic and electronic structures of the HEA NPs,revealing the co-presence of Fe,Co,Mn,Cu and Al elements as well as their different valences across surface and internal regions.The HEA NPs showed remarkable OER performance,exhibiting an overpotential of 280 mV at 10 mA cm-2 and a low Tafel slope of 76.13 mV dec-1 in a 1.0 M KOH solution with high electrochemical stability,superior to commercial RuO2 electrocatalysts.This work provides a new approach for synthesizing nanoscale noble-metal-free HEA electrocatalysts for clean energy conversion applications on a large-scale basis for practical commercialization.
查看更多>>摘要：This paper demonstrates an alternative and simple approach for achieving a fast temperature change on a py-roelectric system through droplet cooling,which leads to enhancement in pyroelectric current generation.The pyroelectric system was composed of a pyroelectric layer of lithium tantalate(LiTaO3)that was sandwiched between two layers of gold/titanium(Au/Ti)as the top and bottom electrodes.Due to both high latent heat and sensible heat of water,there was a rapid heat exchange during the droplet cooling process,and the pyroelectric layer underwent a fast temperature change with the maximum rate of～725 ℃/s.The induced pyroelectric current density reached as high as～8.8 μA/cm2.Such pyro-current density is among the highest reported so far.The pyroelectric response was also investigated by using the surfaces with different wettability.The hydrophilic surfaces underwent faster heat dissipation,leading to the generation of larger current than that of the hydro-phobic surfaces during the droplet cooling process.This work may help expand the utilization of pyroelectric materials in various applications that involve the current generation using pyroelectric effect.
查看更多>>摘要：Porous reactant is the key component in solar thermochemical reactions,significantly affecting the solar energy conversion and fuel production performance.Triply periodic minimal surface(TPMS)structures,with analytical expressions and predictable structure-property relationships,can facilitate the design and optimization of such structures.This work proposes a machine learning-assisted framework to optimize TPMS structures for enhanced reaction efficiency,increased fuel production,and reduced temperature gradients.To mitigate the computational cost of conventional high-throughput optimization,neural network regression models were used to for performance prediction based on input features.The training dataset was generated using a three-dimensional multiphysics model for the thermochemical reduction driven by concentrated solar energy considering fluid flow,heat and mass transfer,and chemical reacions.Both uniform and gradient structures were initially assessed by the three-dimensional model showing gradient design in c and ω were necessary for performance enhancement.Further,with our proposed optimization framework,we found that structures with parameters c1=c2=0.5(uniform in c)and ω1=0.2,ω2=0.8(gradient in ω)achieved the highest relative efficiency(fchem/fchem,ref)of 1.58,a relative fuel production(Δδ/Δδref)of 7.94,and a max relative temperature gradient(dT/dy)/(dT/dy)ref of 0.26.Kinetic properties,i.e.,bulk diffusion and surface exchange coefficient,were also studied showing that for materilas with slow kinetics,the design space in terms of c and ω were highly limited compared to fast kinetics materials.Our framework is adaptable to diverse porous structures and operational conditions,making it a versatile tool for screening porous structures for solar thermochemical applications.This work has the potential to advance the development of efficient solar fuel production systems and scalable industrial applications in renewable energy technologies.
查看更多>>摘要：In this paper,a series of kelp-derived porous carbon(KPC)materials were prepared from kelp by using a pyrolysis-activation method,where KOH with a fixed ratio was applied as the activator under varying activation tem-perature.Eventually,the KPC-based capacitive deionization(CDI)system showed excellent desalination perfor-mance,and the desalination capacity of KPC with an activation temperature of 800 ℃ was highest,reaching 51.33 mgNaCl g-1 at 1.2 V.This work implies the trade-off effect of the activation temperature for the preparation and application of biomass-derived carbon materials,and provides some insights for carbon-based CDI materials.
查看更多>>摘要：Rational design of electrocatalysts is the key to achieving sustainable oxygen evolution reaction(OER).The conjugation of metal organic frameworks(MOFs)with different multicomponent materials to precisely construct heterostructures is fascinating but remains a significant challenge due to different interface energies and nucle-ation kinetics.In this work,hollow multilayer heterogeneous catalyst(CoFeP/CoFeP/NP-C)was constructed using a rigid template sacrifice approach and an ion exchange strategy.By cleverly combining iron-based MOFs(MIL-88A,sacrifice template)nanorods,layered dihydroxides(LDH)nanosheets,and Prussian blue(PB)nancubes to form rich heterojunction and bimetallic phosphide catalysts,and by tuning the reaction kinetics and electron transfer capacities to enrich the active sites,ultimately promoting the intrinsic activity of the catalyst towards OER.Simultaneously,the co-doping of nitrogen and phosphorus in the heterostructure helped to adjust the electronic structure of the heterogeneous catalyst and the conductivity of the matrix,promoting the adsorption and desorption of OER intermediates on the catalyst surface.This work provides a new strategy for designing efficient and stable bimetallic phosphide electrocatalysts.
Mohammad Hosein RezazadehYalda RamezaniFereshteh Meshkani
921-932页
查看更多>>摘要：This study investigates the performance of Ni and Co catalysts based on Fe-promoted MgAl2O4 for CO2 metha-nation,which is a crucial step in mitigating environmental carbon dioxide levels.The MgAl2O4 support was modified with various Fe loading(5,10,and 15 wt％)and fabricated via a novel coprecipitation technique with the help of ultrasonic waves and chosen as support for 15 wt％Ni and Co active phases.Examination of the BET surface properties of the catalysts showed an increase in surface area in the range of 54-82 m2/g and 73-85 m2/g with an increasing Fe loading for Ni and Co catalysts,respectively.Among the Ni-based catalysts,the 15Ni/10FeMgAl2O4 specimen exhibited the best performance(with a 73.31％CO2 conversion and 95.61％selectivity rate)and remarkable lifetime during 10 h at 400 ℃ due to the better reducibility and the increase in hydrogen consumption.However,a rise in Fe amount to 15 wt％led to a reduction in the CO2 conversion to 34.43％.The catalytic outcomes also demonstrated that the presence of Fe in Co/MgAl2O4 catalysts negatively affects catalytic performance.The unpromoted Co/MgAl2O4 sample demonstrated the best performance,achieving a conversion rate of 52.41％at 350 ℃.
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