Transition metal phosphides(TMPs)have been regarded as alternative hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)catalysts owing to their comparable activity to those of noble metal-based catalysts...Transition metal phosphides(TMPs)have been regarded as alternative hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)catalysts owing to their comparable activity to those of noble metal-based catalysts.TMPs have been produced in various morphologies,including hollow and porous nanostructures,which are features deemed desirable for electrocatalytic materials.Templated synthesis routes are often responsible for such morphologies.This paper reviews the latest advances and existing challenges in the synthesis of TMP-based OER and HER catalysts through templated methods.A comprehensive review of the structure-property-performance of TMP-based HER and OER catalysts prepared using different templates is presented.The discussion proceeds according to application,first by HER and further divided among the types of templates used-from hard templates,sacrificial templates,and soft templates to the emerging dynamic hydrogen bubble template.OER catalysts are then reviewed and grouped according to their morphology.Finally,prospective research directions for the synthesis of hollow and porous TMP-based catalysts,such as improvements on both activity and stability of TMPs,design of environmentally benign templates and processes,and analysis of the reaction mechanism through advanced material characterization techniques and theoretical calculations,are suggested.展开更多
Supercapacitors(SCs)are considered promising energy storge systems because of their outstanding power density,fast charge and discharge rate and long-term cycling stability.The exploitation of cheap and efficient elec...Supercapacitors(SCs)are considered promising energy storge systems because of their outstanding power density,fast charge and discharge rate and long-term cycling stability.The exploitation of cheap and efficient electrode materials is the key to improve the performance of supercapacitors.As the battery-type materials,transition metal phosphides(TMPs)possess high theoretical specific capacity,good electrical conductivity and superior structural stability,which have been extensively studied to be electrode materials for supercapacitors.In this review,we summarize the up-to-date progress on TMPs materials from diversified synthetic methods,diverse nanostructures and several prominent TMPs and their composites in application of supercapacitors.In the end,we also propose the remaining challenges toward the rational discovery and synthesis of high-performance TMP electrodes materials for energy storage.展开更多
The exploitation of electrocatalysts with high activity and durability for HER is desirable for future energy systems,but it is still a challenge.NMPs have attracted increasing attentions,but the preparation process o...The exploitation of electrocatalysts with high activity and durability for HER is desirable for future energy systems,but it is still a challenge.NMPs have attracted increasing attentions,but the preparation process often needs toxic regents or dangerous reaction conditions.Herein,we develop a general green method to fabricate metal-rich NMPs anchored on NPG through pyrolyzing DNA cross-linked complexes.The obtained Ru_(2) P-NPG exhibits an ultrasmall overpotential of 7 mV at 10 mA cm^(2) and ultralow Tafel slope of 33 mV dec^(-1) in 1.0 mol L?1 KOH,even better than that of commercial Pt/C.In addition,Ru 2 P-NPG also shows low overpotentials of 29 and 78 mV in 0.5 mol L^(-1) H_(2)SO_(4) and 1.0 mol L^(-1) PBS,respectively.The superior activity can be attributed to the ultrafine dispersion of Ru 2 P nanoparticles for more accessible sites,more defects formed for abundant active sites,the two-dimensional plane structure for accelerated electron transfer and mass transport,as well as the regulation of electron distribution of the catalyst.Moreover,the synthetic method can also be applied to prepare other metal-rich noble metal phosphides(Pd_(3)P-NPG and Rh_(2)P-NPG),which also exhibits high activity for HER.This work provides an effective strategy for designing NMP-based electrocatalysts.展开更多
The electronic modulation characteristics of efficient metal phosphide electrocatalysts can be utilized to tune the performance of oxygen evolution reaction(OER).However,improving the overall water splitting performan...The electronic modulation characteristics of efficient metal phosphide electrocatalysts can be utilized to tune the performance of oxygen evolution reaction(OER).However,improving the overall water splitting performance remains a challenging task.By building metal organic framework(MOF)on MOF heterostructures,an efficient strategy for controlling the electrical structure of MOFs was presented in this study.ZIF-67 was in-situ synthesized on MIL-88(Fe)using a two-step self-assembly method,followed by low-temperature phosphorization to ultimately synthesize FeP-CoP_(3)bimetallic phosphides.By combining atomic orbital theory and theoretical calculations(density functional theory),the results reveal the successful modulation of electronic orbitals in FeP-CoP_(3)bimetallic phosphides,which are synthesized from MOF on MOF structure.The synergistic impact of the metal center Co species and the phase conjugation of both kinds of MOFs are responsible for this regulatory phenomenon.Therefore,the catalyst demonstrates excellent properties,demonstrating HER 81 mV(η10)in a 1.0 mol L^(−1)KOH solution and OER 239 mV(η50)low overpotentials.The FeP-CoP_(3)linked dual electrode alkaline batteries,which are bifunctional electrocatalysts,have a good electrocatalytic ability and may last for 50 h.They require just 1.49 V(η50)for total water breakdown.Through this technique,the electrical structure of electrocatalysts may be altered to increase catalytic activity.展开更多
Oxygen evolution reaction(OER),as an important half‐reaction involved in water splitting,has been intensely studied since the last century.Transition metal phosphide and sulfide‐based compounds have attracted increa...Oxygen evolution reaction(OER),as an important half‐reaction involved in water splitting,has been intensely studied since the last century.Transition metal phosphide and sulfide‐based compounds have attracted increasing attention as active OER catalysts due to their excellent physical and chemical characters,and massive efforts have been devoted to improving the phosphide and sulfide‐based materials with better activity and stability in recent years.In this review,the recent progress on phosphide and sulfide‐based OER electrocatalysts in terms of chemical properties,synthetic methodologies,catalytic performances evaluation and improvement strategy is reviewed.The most accepted reaction pathways as well as the thermodynamics and electrochemistry of the OER are firstly introduced in brief,followed by a summary of the recent research and optimization strategy of phosphide and sulfide‐based OER electrocatalysts.Finally,some mechanistic studies of the active phase of phosphide and sulfide‐based compounds are discussed to give insight into the nature of active catalytic sites.It is expected to indicate guidance for further improving the performances of phosphide and sulfide‐based OER electrocatalysts.展开更多
Li-S batteries have been considered as one of advanced next-generation energy storage systems owing to their remarkable theoretical capacity(1672 m Ah g^(-1))and high energy density(2600 Wh kg^(-1)).However,critical i...Li-S batteries have been considered as one of advanced next-generation energy storage systems owing to their remarkable theoretical capacity(1672 m Ah g^(-1))and high energy density(2600 Wh kg^(-1)).However,critical issues,mainly pertaining to lithium polysulfide shuttle and slow sulfur reaction kinetics,have posed a fatal threat to the electrochemical performances of Li-S batteries.The situation is even worse for high sulfur-loaded and flexible cathodes,which are the essential components for practical Li-S batteries.In response,the use of metal compounds as electrocatalysts in Li-S systems have been confirmed as an effective strategy to date.Particularly,recent years have witnessed many progresses in phosphidesoptimized Li-S chemistry.This has been motivated by the superior electron conductivity and high electrocatalytic activity of phosphides.In this tutorial review,we offer a systematic summary of active metal phosphides as promoters for Li-S chemistry,aiming at helping to understanding the working mechanism of phosphide electrocatalysts and guiding the construction of advanced Li-S batteries.展开更多
Among the sustainable energy sources,hydrogen is the one most promising for alleviating the pollution issues related to the usage of conventional fuels,as it can be produced in an efficient and eco-friendly way via el...Among the sustainable energy sources,hydrogen is the one most promising for alleviating the pollution issues related to the usage of conventional fuels,as it can be produced in an efficient and eco-friendly way via electrocatalytic water splitting.The hydrogen evolution reaction(HER,a half-reaction of water splitting)plays a pivotal role in decreasing the price and increasing the catalytic efficiency of hydrogen production and is efficiently promoted by metal phosphides in different electrolytes.Herein,we summarize the recent advances in the development of metal phosphides as HER electrocatalysts,focus on their synthesis(post-treatment,in situ generation,and electrodeposition methods)and the enhancement of their electrocatalytic activity(via elemental doping,interface and vacancy engineering,construction of specific supports and nanostructures,and the design of bior polymetallic phosphides),and highlight the crucial issues and challenges of future development.展开更多
It is critical to synthesize high-efficiency electrocatalysts to boost the performance of water splitting to meet the requirements of industrial applications. Metal-organic frameworks(MOFs) can function as ideal molec...It is critical to synthesize high-efficiency electrocatalysts to boost the performance of water splitting to meet the requirements of industrial applications. Metal-organic frameworks(MOFs) can function as ideal molecular platforms for the design of highly reactive transition metal phosphides(TMPs), a kind of candidates for high-efficiently electrocatalytic water splitting. The intrinsic activity of the electrocatalysts can be greatly improved via modulating the electronic structure of the catalytic center through the MOF precursors/templates. Moreover, the carbon layer converted in-situ by the organic ligands can not only protect the TMPs from being degraded in the harsh electrochemical environments, but also avoid agglomeration of the catalysts, thereby promoting their activities and stabilities. Furthermore,heteroatom-containing ligands can incorporate N, S or P, etc. atoms into the carbon matrixes after conversion, regulating the coordination microenvironments of the active centers as well as their electronic structures. In this review, we first summarized the latest developments in MOF-derived TMPs by the unique advantages in metal, organic ligand, and morphology regulations for electrocatalytic water splitting. Secondly, we concluded the critical scientific issues currently facing for designing state-of-the-art TMP-based electrocatalysts. Finally, we presented an outlook on this research area, encompassing electrocatalyst construction, catalytic mechanism research, etc.展开更多
Lithium−sulfur batteries are one of the most competitive high-energy batteries due to their high theoretical energy density of _(2)600 W·h·kg^(−1).However,their commercialization is limited by poor cycle sta...Lithium−sulfur batteries are one of the most competitive high-energy batteries due to their high theoretical energy density of _(2)600 W·h·kg^(−1).However,their commercialization is limited by poor cycle stability mainly due to the low intrinsic electrical conductivity of sulfur and its discharged products(Li_(2)S_(2)/Li_(2)S),the sluggish reaction kinetics of sulfur cathode,and the“shuttle effect”of soluble intermediate lithi-um polysulfides in ether-based electrolyte.To address these challenges,catalytic hosts have recently been introduced in sulfur cathodes to en-hance the conversion of soluble polysulfides to the final solid products and thus prevent the dissolution and loss of active-sulfur material.In this review,we summarize the recent progress on the use of metal phosphides and borides of different dimensions as the catalytic host of sulfur cathodes and demonstrate the catalytic conversion mechanism of sulfur cathodes with the help of metal phosphides and borides for high-en-ergy and long-life lithium-sulfur batteries.Finally,future outlooks are proposed on developing advanced catalytic host materials to improve battery performance.展开更多
Transition metal phosphides(TMPs)have exhibited decent performance in an oxygen evolution reaction(OER),which is a kinetic bottleneck in many energy storages and conversion systems.Most reported catalysts are composed...Transition metal phosphides(TMPs)have exhibited decent performance in an oxygen evolution reaction(OER),which is a kinetic bottleneck in many energy storages and conversion systems.Most reported catalysts are composed of three or fewer metallic components.The inherent complexity of multicomponent TMPs with more than four metallic components hinders their investigation in rationally designing the structure and,more importantly,comprehending the component-activity correlation.Through hydrothermal growth and subsequent phosphor-ization,we reported a facile strategy for combining TMPs with tunable elemental compositions(Ni,Fe,Mn,Co,Cu)on a two-dimensional ti-tanium carbide(MXene)flake.The obtained TMPs/MXene hybrid nanostructures demonstrate homogeneously distributed elements.They ex-hibit high electrical conductivity and strong interfacial interaction,resulting in an accelerated reaction kinetics and long-term stability.The res-ults of different component catalysts’OER performance show that NiFeMnCoP/MXene is the most active catalyst,with a low overpotential of 240 mV at 10 mA·cm−2,a small Tafel slope of 41.43 mV·dec−1,and a robust long-term electrochemical stability.According to the electrocata-lytic mechanism investigation,the enhanced NiFeMnCoP/MXene OER performance is due to the strong synergistic effect of the multi-ele-mental composition.Our work,therefore,provides a scalable synthesis route for multi-elemental TMPs and a valuable guideline for efficient MXene-supported catalysts design.展开更多
Metal-organic frameworks(MOFs)with high porosity and variable structure have attracted extensive attention in the field of electrochemistry,but their poor conductivity and stability have limited their development.Mate...Metal-organic frameworks(MOFs)with high porosity and variable structure have attracted extensive attention in the field of electrochemistry,but their poor conductivity and stability have limited their development.Materials derived from MOFs can maintain the structural diversity and porosity characteristics of MOFs while improving their electrical conductivity and stability.Metal phosphides play an important role in electrochemistry because they possess rich active sites,unique physicochemical properties,and a porous structure.Published results show that MOF-derived metal-phosphides materials have great promise in the field of electrochemistry due to their controllable structure,high specific surface area,high stability and excellent electrical conductivity.MOF-derived metal-phosphides with significant electrochemical properties can be obtained by simply,economical and scalable synthetic methods.This work reviews the application of MOF-derived metal phosphides in electrochemistry.Specifically,the synthesis methodology and morphological characterization of MOFs derived metal-phosphides and their application in electrochemistry are described.Based on recent scientific advances,we discuss the challenges and opportunities for future research on MOF-derived metal-phosphides materials.展开更多
Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass exhibited excellent magnetic refrigeration material with a wide temperature range and high refrigeration capacity(RC)was reported.Er_(20)Ho_(20)Dy_(20)Cu_...Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass exhibited excellent magnetic refrigeration material with a wide temperature range and high refrigeration capacity(RC)was reported.Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass was observed with typical spin glass behavior around 15.5 K.In addition,we find that the magnetic entropy change(-△S_(M))originates from the sample undergoing a ferromagnetic(FM)to paramagnetic(PM)transition around 20 K.Under a field change from 0 T to 7 T,the value of maximum magnetic entropy change(-△S_(M)^(max))reaches 12.5 J/kg·K,and the corresponding value of RC reaches 487.7 J/kg in the temperature range from 6 K to 60 K.The large RC and wide temperature range make the Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass be a promising material for application in magnetic refrigerators.展开更多
Thioetherification between mercaptan and diolefin is an efficient process to remove mercaptans in FCC gasoline at mild condition, during which the selective hydrogenation of diolefin to monoolefin is also expected. He...Thioetherification between mercaptan and diolefin is an efficient process to remove mercaptans in FCC gasoline at mild condition, during which the selective hydrogenation of diolefin to monoolefin is also expected. Here, Si O2 supported transition metal(Fe, Co, Ni, Mo and W) phosphides were tested for the thioetherification of isoprene and butanethiol on a fixed-bed reactor at 120℃ and 1.5 MPa H2, and their structure before and after reaction was characterized by means of XRD, HRTEM, N2 sorption, CO chemisorption, NH3-TPD, XPS and TG. It was found that, among different metal phosphides, Mo P/Si O2 showed the best performance, and the optimal nominal Mo P loading was 25%. Apart from the nature of metal, the density of metal and acid sites determined the catalyst performance. Metal site was mainly responsible for hydrogenation of isoprene, while acid site dominantly contributed to the thioetherification and the polymerization of olefins. Moreover, a balance between metallic and acidic functions is required to arrive at a desired performance. Excessive metal sites or acid sites led to the over-hydrogenation of isoprene or the severe polymerization of olefins, respectively. 25%Mo P/Si O2 was tested for 37 h time on stream, and butanethiol conversion maintained at 100%; although isoprene conversion remarkably decreased, the selectivity to isopentenes exceeded 80% after reaction for 11 h. We suggest that the deactivation of Mo P/Si O2 is mainly ascribed to the butanethiol poisoning and the carbonaceous deposit, especially the former.展开更多
Designing cost-effective and high-efficiency electrocatalysts is critical to the water splitting performance during hydrogen generation.Herein,we have developed Fe_(2)P-Co_(2)P heterostructure nanowire arrays with exc...Designing cost-effective and high-efficiency electrocatalysts is critical to the water splitting performance during hydrogen generation.Herein,we have developed Fe_(2)P-Co_(2)P heterostructure nanowire arrays with excellent lattice torsions and grain boundaries for highly efficient water splitting.According to the microstructural investigations and theoretical calculations,the lattice torsion interface not only contributes to the exposure of more active sites but also effectively tunes the adsorption energy of hydrogen/oxygen intermediates via the accumulation of charge redistribution.As a result,the Fe_(2)P-Co_(2)P heterostructure nanowire array exhibits exceptional bifunctional catalytic activity with overpotentials of 65 and 198 mV at 10 mA cm^(-2) for hydrogen and oxygen evolution reactions,respectively.Moreover,the Fe_(2)P-Co_(2)P/NF-assembled electrolyzer can deliver 10 mA cm^(-2) at an ultralow voltage of1.51 V while resulting in a high solar-to-hydrogen conversion efficiency of 19.8%in the solar-driven water electrolysis cell.展开更多
Designing highly active,durable,and nonprecious metal-based bifunctional electrocatalysts for overall water electrolysis is of urgent scientific importance to realize the sustainable hydrogen production,which remains ...Designing highly active,durable,and nonprecious metal-based bifunctional electrocatalysts for overall water electrolysis is of urgent scientific importance to realize the sustainable hydrogen production,which remains a grand challenge.Herein,an innovative approach is demonstrated to synthesize flower-like 3D homogenous trimetallic Mn,Ni,Co phosphide catalysts directly on nickel foam via electrodeposition followed by plasma phosphidation.The electrochemical activity of the catalysts with varying Mn:Ni:Co ratios is assessed to identify the optimal composition,demonstrating that the equimolar trimetallic phosphide yields an outstanding HER catalytic performance with a current density of 10 mA cm^(-2) at an ultra-low overpotential of~14 mV,outperforming the best reported electrocatalysts.This is asserted by the DFT calculations,revealing strong interaction of the metals and the P atom,resulting in enhanced water activation and optimized G_(H)^(*)values for the HER process.Moreover,this optimal composition appreciably catalyzes the OER by exposing more intrinsic active species in-situ formed on the catalyst surface during the OER.Therefore,the Mn_(1)-Ni_(1)-Co_(1)-P-(O)/NF catalyst exhibits a decreased overpotential of~289 mV at 10 mA cm^(-2).More importantly,the electrocatalyst sustains perfect durability up to 48 h at a current density of 10 mA cm^(-2) and continued 5000 cycling stability for both HER and OER.Meanwhile,the assembled MNC-P/NF||MNC-P/NF full water electrolyzer system attains an extremely low cell voltage of 1.48 V at 10 mA cm^(-2).Significantly,the robust stability of the overall system results in a remarkable current retention of~96%after a continuous 50-h run.Therefore,this study provides a facile design and a scalable construction of superb bifunctional ternary MNC-phosphide electrocatalysts for efficient electrochemical energy production systems.展开更多
Exploring feasible synthesis approaches to highly efficient and robust bifunctional electrocatalysts toward both oxygen evolution reaction(OER)and oxygen reduction reaction(ORR)is triggering researcher’s even-increas...Exploring feasible synthesis approaches to highly efficient and robust bifunctional electrocatalysts toward both oxygen evolution reaction(OER)and oxygen reduction reaction(ORR)is triggering researcher’s even-increasing interest in rechargeable Zn-air batteries.Herein,sulfur-doped bimetal FeCo phosphide nanoparticles dispersed on N,P,S-tri-doped graphene(donated as S-FeCo3P/NPSG)are rationally prepared through a controllable one-step carbothermal-phosphorization strategy.The modified charge distribution and electron-donor properties of S-FeCo3P/NPSG caused by S decoration render a significantly beneficial effect on the electrocatalytic activities.Consequently,the S-FeCo3P/NPSG electrode exhibits extraordinary bifunctional activities toward oxygen electrochemistry of the OER overpotential of 290 m V at 10 m A cm^(-2) and the ORR half-wave potential of 0.83 V,approaching to that of noblemetal IrO_(2)(289 m V)and Pt/C(0.84 V),respectively,but with more stronger operation stability in alkaline media.When S-FeCo3P/NPSG serves as the air cathode for liquid-state Zn-air battery,the large peak power density and energy density,as well as superb discharge-charge durability(cycling life>600 h)of this device are obtained.Furthermore,all-solid-state Zn-air battery with S-FeCo3P/NPSG as air electrode also displays excellent mechanical flexibility,high power density and stable cycling stability.The self-reconstruction behavior of the S-FeCo3P/NPSG cathode catalysts is also investigated during the electrocatalytic Zn-air battery operation.This work would provide some novel inspiration from aspects of bonding and charge distribution for the rational construction of active and cost-efficient bifucntional oxygen electrocatalysts for energy storage and conversion devices.展开更多
SiO2-supported Ni-Mo bimetallic phosphides were prepared by temperature-programmed reduction (TPR) method from the phosphate precur- sors calcined at different temperatures. Their properties were characterized by me...SiO2-supported Ni-Mo bimetallic phosphides were prepared by temperature-programmed reduction (TPR) method from the phosphate precur- sors calcined at different temperatures. Their properties were characterized by means of ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS), H2 temperature-programmed reduction (H2-TPR), X-ray diffraction (XRD), transmission electron microscopy (TEM), CO chemisorption, H2 and NH3 temperature-programmed desorptions (H2-TPD and NH3-TPD). Their catalytic performances for the deoxygena- tion of methyl laurate were tested in a fixed-bed reactor. When the precursors were calcined at 400 and 500 ℃, respectively, NiMoP2 phase could be formed apart from Ni2P and MoP phases in the prepared C400 and C500 catalysts. However, when the precursors were calcined at 600, 700 and 800 ℃, respectively, only Ni2P and MoP phases could be detected in the prepared C600, C700 and C800 catalysts. Also, in C400, C500 and C600 catalysts, Mo atoms were found to be entered in the lattice of Ni2P phase, but the entering extent became less with the increase of calcination temperature. As the calcination temperature of the precursor increased, the interaction between Ni and Mo in the prepared catalysts decreased, and the phosphide crystallite size tended to increase, subsequently leading to the decrease in the surface metal site density and the acid amount. C600 catalyst showed the highest activity among the tested ones for the deoxygenation of methyl laurate. As the calcination temperature of the precursor increased, the selectivity to C12 hydrocarbons decreased while the selectivity to C11 hydrocarbons tended to increase. This can be mainly attributed to the decreased Ni-Mo interaction and the increased phosphide particle size. In sum, the structure and performance of Ni-Mo bimetallic phosphide catalyst can be tuned by the calcination temperature of precursor.展开更多
Progress in materials development is often paced by the time required to produce and evaluate a large number of alloys with different chemical compositions.This applies especially to refractory high-entropy alloys(RHE...Progress in materials development is often paced by the time required to produce and evaluate a large number of alloys with different chemical compositions.This applies especially to refractory high-entropy alloys(RHEAs),which are difficult to synthesize and process by conventional methods.To evaluate a possible way to accelerate the process,high-throughput laser metal deposition was used in this work to prepare a quinary RHEA,TiZrNbHfTa,as well as its quaternary and ternary subsystems by in-situ alloying of elemental powders.Compositionally graded variants of the quinary RHEA were also analyzed.Our results show that the influence of various parameters such as powder shape and purity,alloy composition,and especially the solidification range,on the processability,microstructure,porosity,and mechanical properties can be investigated rapidly.The strength of these alloys was mainly affected by the oxygen and nitrogen contents of the starting powders,while substitutional solid solution strengthening played a minor role.展开更多
Rational design of efficient pH-universal hydrogen evolution reaction catalysts to enable large-scale hydrogen production via electrochemical water splitting is of great significance,yet a challenging task.Herein,Ru a...Rational design of efficient pH-universal hydrogen evolution reaction catalysts to enable large-scale hydrogen production via electrochemical water splitting is of great significance,yet a challenging task.Herein,Ru atoms in the Ru_(2)P structure were replaced with M=Co,Ni,or Mo to produce M_(2-x)Ru_(x)P nanocrystals.The metals show strong site preference,with Co and Ni occupying the tetrahedral sites and Ru the square pyramidal sites of the CoRuP and NiRuP Ru_(2)P-type structures.The presence of Co or Ni in the tetrahedral sites leads to charge redistribution for Ru and,according to density functional theory calculations,a significant increase in the Ru d-band centers.As a result,the intrinsic activity of CoRuP and NiRuP increases considerably compared to Ru_(2)P in both acidic and alkaline media.The effect is not observed for MoRuP,in which Mo prefers to occupy the pyramidal sites.In particular,CoRuP shows state-of-the-art activity,outperforming Ru_(2)P with Pt-like activity in 0.5 M H_(2)SO_(4)(η_(10)=12.3 mV;η100=52 mV;turnover frequency(TOF)=4.7 s^(-1)).It remains extraordinarily active in alkaline conditions(η10=12.9 mV;η_(100)=43.5 mV)with a TOF of 4.5 s^(-1),which is 4x higher than that of Ru_(2)P and 10x that of Pt/C.Further increase in the Co content does not lead to drastic loss of activity,especially in alkaline medium,where,for example,the TOF of Co_(1.9)Ru_(0.1)P remains comparable to that of Ru_(2)P and higher than that of Pt/C,highlighting the viability of the adopted approach to prepare cost-efficient catalysts.展开更多
基金the support from the CIPHER Project(IIID 2018-008)funded by the Commission on Higher Education-Philippine California Advanced Research Institutes(CHED-PCARI)。
文摘Transition metal phosphides(TMPs)have been regarded as alternative hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)catalysts owing to their comparable activity to those of noble metal-based catalysts.TMPs have been produced in various morphologies,including hollow and porous nanostructures,which are features deemed desirable for electrocatalytic materials.Templated synthesis routes are often responsible for such morphologies.This paper reviews the latest advances and existing challenges in the synthesis of TMP-based OER and HER catalysts through templated methods.A comprehensive review of the structure-property-performance of TMP-based HER and OER catalysts prepared using different templates is presented.The discussion proceeds according to application,first by HER and further divided among the types of templates used-from hard templates,sacrificial templates,and soft templates to the emerging dynamic hydrogen bubble template.OER catalysts are then reviewed and grouped according to their morphology.Finally,prospective research directions for the synthesis of hollow and porous TMP-based catalysts,such as improvements on both activity and stability of TMPs,design of environmentally benign templates and processes,and analysis of the reaction mechanism through advanced material characterization techniques and theoretical calculations,are suggested.
基金supported by National Undergraduate Training Programs for Innovations[grant number 202210225259]the Outstanding Youth Project of Natural Science Foundation in Heilongjiang Province(YQ2022E040)+3 种基金the Shandong Provincial Natural Science Foundation(ZR2022ME166)the Postdoctoral Scientific Research Developmental Fund of Heilongjiang Province(LBH-Q20023)the University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province(UNPYSCT-2020197)the 111 Project(B20088).
文摘Supercapacitors(SCs)are considered promising energy storge systems because of their outstanding power density,fast charge and discharge rate and long-term cycling stability.The exploitation of cheap and efficient electrode materials is the key to improve the performance of supercapacitors.As the battery-type materials,transition metal phosphides(TMPs)possess high theoretical specific capacity,good electrical conductivity and superior structural stability,which have been extensively studied to be electrode materials for supercapacitors.In this review,we summarize the up-to-date progress on TMPs materials from diversified synthetic methods,diverse nanostructures and several prominent TMPs and their composites in application of supercapacitors.In the end,we also propose the remaining challenges toward the rational discovery and synthesis of high-performance TMP electrodes materials for energy storage.
基金This work was supported by the Fundamental Research Funds for the Central Universities(No.2022XJHH02)the National Key Research and Development Program of China(No.2019YFC1907602).
文摘The exploitation of electrocatalysts with high activity and durability for HER is desirable for future energy systems,but it is still a challenge.NMPs have attracted increasing attentions,but the preparation process often needs toxic regents or dangerous reaction conditions.Herein,we develop a general green method to fabricate metal-rich NMPs anchored on NPG through pyrolyzing DNA cross-linked complexes.The obtained Ru_(2) P-NPG exhibits an ultrasmall overpotential of 7 mV at 10 mA cm^(2) and ultralow Tafel slope of 33 mV dec^(-1) in 1.0 mol L?1 KOH,even better than that of commercial Pt/C.In addition,Ru 2 P-NPG also shows low overpotentials of 29 and 78 mV in 0.5 mol L^(-1) H_(2)SO_(4) and 1.0 mol L^(-1) PBS,respectively.The superior activity can be attributed to the ultrafine dispersion of Ru 2 P nanoparticles for more accessible sites,more defects formed for abundant active sites,the two-dimensional plane structure for accelerated electron transfer and mass transport,as well as the regulation of electron distribution of the catalyst.Moreover,the synthetic method can also be applied to prepare other metal-rich noble metal phosphides(Pd_(3)P-NPG and Rh_(2)P-NPG),which also exhibits high activity for HER.This work provides an effective strategy for designing NMP-based electrocatalysts.
文摘The electronic modulation characteristics of efficient metal phosphide electrocatalysts can be utilized to tune the performance of oxygen evolution reaction(OER).However,improving the overall water splitting performance remains a challenging task.By building metal organic framework(MOF)on MOF heterostructures,an efficient strategy for controlling the electrical structure of MOFs was presented in this study.ZIF-67 was in-situ synthesized on MIL-88(Fe)using a two-step self-assembly method,followed by low-temperature phosphorization to ultimately synthesize FeP-CoP_(3)bimetallic phosphides.By combining atomic orbital theory and theoretical calculations(density functional theory),the results reveal the successful modulation of electronic orbitals in FeP-CoP_(3)bimetallic phosphides,which are synthesized from MOF on MOF structure.The synergistic impact of the metal center Co species and the phase conjugation of both kinds of MOFs are responsible for this regulatory phenomenon.Therefore,the catalyst demonstrates excellent properties,demonstrating HER 81 mV(η10)in a 1.0 mol L^(−1)KOH solution and OER 239 mV(η50)low overpotentials.The FeP-CoP_(3)linked dual electrode alkaline batteries,which are bifunctional electrocatalysts,have a good electrocatalytic ability and may last for 50 h.They require just 1.49 V(η50)for total water breakdown.Through this technique,the electrical structure of electrocatalysts may be altered to increase catalytic activity.
文摘Oxygen evolution reaction(OER),as an important half‐reaction involved in water splitting,has been intensely studied since the last century.Transition metal phosphide and sulfide‐based compounds have attracted increasing attention as active OER catalysts due to their excellent physical and chemical characters,and massive efforts have been devoted to improving the phosphide and sulfide‐based materials with better activity and stability in recent years.In this review,the recent progress on phosphide and sulfide‐based OER electrocatalysts in terms of chemical properties,synthetic methodologies,catalytic performances evaluation and improvement strategy is reviewed.The most accepted reaction pathways as well as the thermodynamics and electrochemistry of the OER are firstly introduced in brief,followed by a summary of the recent research and optimization strategy of phosphide and sulfide‐based OER electrocatalysts.Finally,some mechanistic studies of the active phase of phosphide and sulfide‐based compounds are discussed to give insight into the nature of active catalytic sites.It is expected to indicate guidance for further improving the performances of phosphide and sulfide‐based OER electrocatalysts.
基金supported by the Project of State Key Laboratory of Environment-Friendly Energy Materials(SWUST,China,Grant Nos.19FKSY16 and 18ZD320304)。
文摘Li-S batteries have been considered as one of advanced next-generation energy storage systems owing to their remarkable theoretical capacity(1672 m Ah g^(-1))and high energy density(2600 Wh kg^(-1)).However,critical issues,mainly pertaining to lithium polysulfide shuttle and slow sulfur reaction kinetics,have posed a fatal threat to the electrochemical performances of Li-S batteries.The situation is even worse for high sulfur-loaded and flexible cathodes,which are the essential components for practical Li-S batteries.In response,the use of metal compounds as electrocatalysts in Li-S systems have been confirmed as an effective strategy to date.Particularly,recent years have witnessed many progresses in phosphidesoptimized Li-S chemistry.This has been motivated by the superior electron conductivity and high electrocatalytic activity of phosphides.In this tutorial review,we offer a systematic summary of active metal phosphides as promoters for Li-S chemistry,aiming at helping to understanding the working mechanism of phosphide electrocatalysts and guiding the construction of advanced Li-S batteries.
文摘Among the sustainable energy sources,hydrogen is the one most promising for alleviating the pollution issues related to the usage of conventional fuels,as it can be produced in an efficient and eco-friendly way via electrocatalytic water splitting.The hydrogen evolution reaction(HER,a half-reaction of water splitting)plays a pivotal role in decreasing the price and increasing the catalytic efficiency of hydrogen production and is efficiently promoted by metal phosphides in different electrolytes.Herein,we summarize the recent advances in the development of metal phosphides as HER electrocatalysts,focus on their synthesis(post-treatment,in situ generation,and electrodeposition methods)and the enhancement of their electrocatalytic activity(via elemental doping,interface and vacancy engineering,construction of specific supports and nanostructures,and the design of bior polymetallic phosphides),and highlight the crucial issues and challenges of future development.
基金supported by the National Natural Science Foundation of China (21901088, 21901089, 22161021, 21971091)the Natural Science Foundation of Jiangxi Province(20192ACB20013)+1 种基金support of Jiangxi Province (jxsq2018106041)the “Young Elite Scientists Sponsorship Program” by CAST。
文摘It is critical to synthesize high-efficiency electrocatalysts to boost the performance of water splitting to meet the requirements of industrial applications. Metal-organic frameworks(MOFs) can function as ideal molecular platforms for the design of highly reactive transition metal phosphides(TMPs), a kind of candidates for high-efficiently electrocatalytic water splitting. The intrinsic activity of the electrocatalysts can be greatly improved via modulating the electronic structure of the catalytic center through the MOF precursors/templates. Moreover, the carbon layer converted in-situ by the organic ligands can not only protect the TMPs from being degraded in the harsh electrochemical environments, but also avoid agglomeration of the catalysts, thereby promoting their activities and stabilities. Furthermore,heteroatom-containing ligands can incorporate N, S or P, etc. atoms into the carbon matrixes after conversion, regulating the coordination microenvironments of the active centers as well as their electronic structures. In this review, we first summarized the latest developments in MOF-derived TMPs by the unique advantages in metal, organic ligand, and morphology regulations for electrocatalytic water splitting. Secondly, we concluded the critical scientific issues currently facing for designing state-of-the-art TMP-based electrocatalysts. Finally, we presented an outlook on this research area, encompassing electrocatalyst construction, catalytic mechanism research, etc.
基金financially supported by the National Natural Science Foundation of China (Nos. 51725401, 51904030, and 21935006)
文摘Lithium−sulfur batteries are one of the most competitive high-energy batteries due to their high theoretical energy density of _(2)600 W·h·kg^(−1).However,their commercialization is limited by poor cycle stability mainly due to the low intrinsic electrical conductivity of sulfur and its discharged products(Li_(2)S_(2)/Li_(2)S),the sluggish reaction kinetics of sulfur cathode,and the“shuttle effect”of soluble intermediate lithi-um polysulfides in ether-based electrolyte.To address these challenges,catalytic hosts have recently been introduced in sulfur cathodes to en-hance the conversion of soluble polysulfides to the final solid products and thus prevent the dissolution and loss of active-sulfur material.In this review,we summarize the recent progress on the use of metal phosphides and borides of different dimensions as the catalytic host of sulfur cathodes and demonstrate the catalytic conversion mechanism of sulfur cathodes with the help of metal phosphides and borides for high-en-ergy and long-life lithium-sulfur batteries.Finally,future outlooks are proposed on developing advanced catalytic host materials to improve battery performance.
基金the National Nat-ural Science Foundation of China(No.51771132)the Open Fund Project of Qinghai Minzu University-Nanoma-terials and Nanotechnology Team&Platform(No.2021-QHMU-PI-nano-KF01).
文摘Transition metal phosphides(TMPs)have exhibited decent performance in an oxygen evolution reaction(OER),which is a kinetic bottleneck in many energy storages and conversion systems.Most reported catalysts are composed of three or fewer metallic components.The inherent complexity of multicomponent TMPs with more than four metallic components hinders their investigation in rationally designing the structure and,more importantly,comprehending the component-activity correlation.Through hydrothermal growth and subsequent phosphor-ization,we reported a facile strategy for combining TMPs with tunable elemental compositions(Ni,Fe,Mn,Co,Cu)on a two-dimensional ti-tanium carbide(MXene)flake.The obtained TMPs/MXene hybrid nanostructures demonstrate homogeneously distributed elements.They ex-hibit high electrical conductivity and strong interfacial interaction,resulting in an accelerated reaction kinetics and long-term stability.The res-ults of different component catalysts’OER performance show that NiFeMnCoP/MXene is the most active catalyst,with a low overpotential of 240 mV at 10 mA·cm−2,a small Tafel slope of 41.43 mV·dec−1,and a robust long-term electrochemical stability.According to the electrocata-lytic mechanism investigation,the enhanced NiFeMnCoP/MXene OER performance is due to the strong synergistic effect of the multi-ele-mental composition.Our work,therefore,provides a scalable synthesis route for multi-elemental TMPs and a valuable guideline for efficient MXene-supported catalysts design.
基金supported by the National Natural Science Foundation of China(U1904215)Natural Science Foundation of Jiangsu Province(BK20200044)Changjiang scholars program of the Ministry of Education(Q2018270)。
文摘Metal-organic frameworks(MOFs)with high porosity and variable structure have attracted extensive attention in the field of electrochemistry,but their poor conductivity and stability have limited their development.Materials derived from MOFs can maintain the structural diversity and porosity characteristics of MOFs while improving their electrical conductivity and stability.Metal phosphides play an important role in electrochemistry because they possess rich active sites,unique physicochemical properties,and a porous structure.Published results show that MOF-derived metal-phosphides materials have great promise in the field of electrochemistry due to their controllable structure,high specific surface area,high stability and excellent electrical conductivity.MOF-derived metal-phosphides with significant electrochemical properties can be obtained by simply,economical and scalable synthetic methods.This work reviews the application of MOF-derived metal phosphides in electrochemistry.Specifically,the synthesis methodology and morphological characterization of MOFs derived metal-phosphides and their application in electrochemistry are described.Based on recent scientific advances,we discuss the challenges and opportunities for future research on MOF-derived metal-phosphides materials.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.52371203 and 52271192)the Ministry of Science and Technology of China(Grant No.2021YFB3501201)。
文摘Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass exhibited excellent magnetic refrigeration material with a wide temperature range and high refrigeration capacity(RC)was reported.Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass was observed with typical spin glass behavior around 15.5 K.In addition,we find that the magnetic entropy change(-△S_(M))originates from the sample undergoing a ferromagnetic(FM)to paramagnetic(PM)transition around 20 K.Under a field change from 0 T to 7 T,the value of maximum magnetic entropy change(-△S_(M)^(max))reaches 12.5 J/kg·K,and the corresponding value of RC reaches 487.7 J/kg in the temperature range from 6 K to 60 K.The large RC and wide temperature range make the Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass be a promising material for application in magnetic refrigerators.
基金supported by the State Key Laboratory of Catalytic Materials and Reaction Engineering(RIPP,SINOPEC)
文摘Thioetherification between mercaptan and diolefin is an efficient process to remove mercaptans in FCC gasoline at mild condition, during which the selective hydrogenation of diolefin to monoolefin is also expected. Here, Si O2 supported transition metal(Fe, Co, Ni, Mo and W) phosphides were tested for the thioetherification of isoprene and butanethiol on a fixed-bed reactor at 120℃ and 1.5 MPa H2, and their structure before and after reaction was characterized by means of XRD, HRTEM, N2 sorption, CO chemisorption, NH3-TPD, XPS and TG. It was found that, among different metal phosphides, Mo P/Si O2 showed the best performance, and the optimal nominal Mo P loading was 25%. Apart from the nature of metal, the density of metal and acid sites determined the catalyst performance. Metal site was mainly responsible for hydrogenation of isoprene, while acid site dominantly contributed to the thioetherification and the polymerization of olefins. Moreover, a balance between metallic and acidic functions is required to arrive at a desired performance. Excessive metal sites or acid sites led to the over-hydrogenation of isoprene or the severe polymerization of olefins, respectively. 25%Mo P/Si O2 was tested for 37 h time on stream, and butanethiol conversion maintained at 100%; although isoprene conversion remarkably decreased, the selectivity to isopentenes exceeded 80% after reaction for 11 h. We suggest that the deactivation of Mo P/Si O2 is mainly ascribed to the butanethiol poisoning and the carbonaceous deposit, especially the former.
基金financially supported by the National Natural Science Foundation of China(U2002213)the Creative Project of Engineering Research Center of Alternative Energy Materials&Devices,Ministry of Education,Sichuan University(AEMD202207)+7 种基金the Open Foundation of Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials of Guangxi University(2022GXYSOF10)the Guangdong Colleges&Universities Characteristic Innovation Project(2021KTSCX263)the Guangdong Education&Scientific Research Project(2021GXJK535)the Guangzhou Panyu Polytechnic Science&Technology Project(2021KJ01)the East-Land Middle-aged and Young Backbone Teacher of Yunnan University(C176220200)the Yunnan Applied Basic Research Projects(202001BB050006,202001BB050007)the Double Tops Joint Fund of the Yunnan Science and Technology Bureau and Yunnan University(2019FY003025)the Double First Class University Plan(C176220100042)。
文摘Designing cost-effective and high-efficiency electrocatalysts is critical to the water splitting performance during hydrogen generation.Herein,we have developed Fe_(2)P-Co_(2)P heterostructure nanowire arrays with excellent lattice torsions and grain boundaries for highly efficient water splitting.According to the microstructural investigations and theoretical calculations,the lattice torsion interface not only contributes to the exposure of more active sites but also effectively tunes the adsorption energy of hydrogen/oxygen intermediates via the accumulation of charge redistribution.As a result,the Fe_(2)P-Co_(2)P heterostructure nanowire array exhibits exceptional bifunctional catalytic activity with overpotentials of 65 and 198 mV at 10 mA cm^(-2) for hydrogen and oxygen evolution reactions,respectively.Moreover,the Fe_(2)P-Co_(2)P/NF-assembled electrolyzer can deliver 10 mA cm^(-2) at an ultralow voltage of1.51 V while resulting in a high solar-to-hydrogen conversion efficiency of 19.8%in the solar-driven water electrolysis cell.
文摘Designing highly active,durable,and nonprecious metal-based bifunctional electrocatalysts for overall water electrolysis is of urgent scientific importance to realize the sustainable hydrogen production,which remains a grand challenge.Herein,an innovative approach is demonstrated to synthesize flower-like 3D homogenous trimetallic Mn,Ni,Co phosphide catalysts directly on nickel foam via electrodeposition followed by plasma phosphidation.The electrochemical activity of the catalysts with varying Mn:Ni:Co ratios is assessed to identify the optimal composition,demonstrating that the equimolar trimetallic phosphide yields an outstanding HER catalytic performance with a current density of 10 mA cm^(-2) at an ultra-low overpotential of~14 mV,outperforming the best reported electrocatalysts.This is asserted by the DFT calculations,revealing strong interaction of the metals and the P atom,resulting in enhanced water activation and optimized G_(H)^(*)values for the HER process.Moreover,this optimal composition appreciably catalyzes the OER by exposing more intrinsic active species in-situ formed on the catalyst surface during the OER.Therefore,the Mn_(1)-Ni_(1)-Co_(1)-P-(O)/NF catalyst exhibits a decreased overpotential of~289 mV at 10 mA cm^(-2).More importantly,the electrocatalyst sustains perfect durability up to 48 h at a current density of 10 mA cm^(-2) and continued 5000 cycling stability for both HER and OER.Meanwhile,the assembled MNC-P/NF||MNC-P/NF full water electrolyzer system attains an extremely low cell voltage of 1.48 V at 10 mA cm^(-2).Significantly,the robust stability of the overall system results in a remarkable current retention of~96%after a continuous 50-h run.Therefore,this study provides a facile design and a scalable construction of superb bifunctional ternary MNC-phosphide electrocatalysts for efficient electrochemical energy production systems.
基金supported by the National Natural Science Foundation of China(21875118,22179065,and 22105108)the Natural Science Foundation of Tianjin(19JCZDJC37700)+1 种基金the 111 project(B12015)China Postdoctoral Science Foundation(2020M680860)。
文摘Exploring feasible synthesis approaches to highly efficient and robust bifunctional electrocatalysts toward both oxygen evolution reaction(OER)and oxygen reduction reaction(ORR)is triggering researcher’s even-increasing interest in rechargeable Zn-air batteries.Herein,sulfur-doped bimetal FeCo phosphide nanoparticles dispersed on N,P,S-tri-doped graphene(donated as S-FeCo3P/NPSG)are rationally prepared through a controllable one-step carbothermal-phosphorization strategy.The modified charge distribution and electron-donor properties of S-FeCo3P/NPSG caused by S decoration render a significantly beneficial effect on the electrocatalytic activities.Consequently,the S-FeCo3P/NPSG electrode exhibits extraordinary bifunctional activities toward oxygen electrochemistry of the OER overpotential of 290 m V at 10 m A cm^(-2) and the ORR half-wave potential of 0.83 V,approaching to that of noblemetal IrO_(2)(289 m V)and Pt/C(0.84 V),respectively,but with more stronger operation stability in alkaline media.When S-FeCo3P/NPSG serves as the air cathode for liquid-state Zn-air battery,the large peak power density and energy density,as well as superb discharge-charge durability(cycling life>600 h)of this device are obtained.Furthermore,all-solid-state Zn-air battery with S-FeCo3P/NPSG as air electrode also displays excellent mechanical flexibility,high power density and stable cycling stability.The self-reconstruction behavior of the S-FeCo3P/NPSG cathode catalysts is also investigated during the electrocatalytic Zn-air battery operation.This work would provide some novel inspiration from aspects of bonding and charge distribution for the rational construction of active and cost-efficient bifucntional oxygen electrocatalysts for energy storage and conversion devices.
基金supported by the National Natural Science Foundation of China(No.21176177)the Natural Science Foundation of Tianjin(No.12JCYBJC13200)State Key Laboratory of Catalytic Materials and Reaction Engineering(RIPP,SINOPEC)
文摘SiO2-supported Ni-Mo bimetallic phosphides were prepared by temperature-programmed reduction (TPR) method from the phosphate precur- sors calcined at different temperatures. Their properties were characterized by means of ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS), H2 temperature-programmed reduction (H2-TPR), X-ray diffraction (XRD), transmission electron microscopy (TEM), CO chemisorption, H2 and NH3 temperature-programmed desorptions (H2-TPD and NH3-TPD). Their catalytic performances for the deoxygena- tion of methyl laurate were tested in a fixed-bed reactor. When the precursors were calcined at 400 and 500 ℃, respectively, NiMoP2 phase could be formed apart from Ni2P and MoP phases in the prepared C400 and C500 catalysts. However, when the precursors were calcined at 600, 700 and 800 ℃, respectively, only Ni2P and MoP phases could be detected in the prepared C600, C700 and C800 catalysts. Also, in C400, C500 and C600 catalysts, Mo atoms were found to be entered in the lattice of Ni2P phase, but the entering extent became less with the increase of calcination temperature. As the calcination temperature of the precursor increased, the interaction between Ni and Mo in the prepared catalysts decreased, and the phosphide crystallite size tended to increase, subsequently leading to the decrease in the surface metal site density and the acid amount. C600 catalyst showed the highest activity among the tested ones for the deoxygenation of methyl laurate. As the calcination temperature of the precursor increased, the selectivity to C12 hydrocarbons decreased while the selectivity to C11 hydrocarbons tended to increase. This can be mainly attributed to the decreased Ni-Mo interaction and the increased phosphide particle size. In sum, the structure and performance of Ni-Mo bimetallic phosphide catalyst can be tuned by the calcination temperature of precursor.
基金GL and ELG acknowledge funding from the German Research Foundation in the framework of the priority program SPP 2006—Compositionally Complex Alloys—High Entropy Alloys,projects LA 3607/3-1 and GU 1075/12-1.EPG is supported by the U.S.Department of Energy,Office of Science,Basic Energy Sciences,Materials Sciences and Engineering Division.
文摘Progress in materials development is often paced by the time required to produce and evaluate a large number of alloys with different chemical compositions.This applies especially to refractory high-entropy alloys(RHEAs),which are difficult to synthesize and process by conventional methods.To evaluate a possible way to accelerate the process,high-throughput laser metal deposition was used in this work to prepare a quinary RHEA,TiZrNbHfTa,as well as its quaternary and ternary subsystems by in-situ alloying of elemental powders.Compositionally graded variants of the quinary RHEA were also analyzed.Our results show that the influence of various parameters such as powder shape and purity,alloy composition,and especially the solidification range,on the processability,microstructure,porosity,and mechanical properties can be investigated rapidly.The strength of these alloys was mainly affected by the oxygen and nitrogen contents of the starting powders,while substitutional solid solution strengthening played a minor role.
文摘Rational design of efficient pH-universal hydrogen evolution reaction catalysts to enable large-scale hydrogen production via electrochemical water splitting is of great significance,yet a challenging task.Herein,Ru atoms in the Ru_(2)P structure were replaced with M=Co,Ni,or Mo to produce M_(2-x)Ru_(x)P nanocrystals.The metals show strong site preference,with Co and Ni occupying the tetrahedral sites and Ru the square pyramidal sites of the CoRuP and NiRuP Ru_(2)P-type structures.The presence of Co or Ni in the tetrahedral sites leads to charge redistribution for Ru and,according to density functional theory calculations,a significant increase in the Ru d-band centers.As a result,the intrinsic activity of CoRuP and NiRuP increases considerably compared to Ru_(2)P in both acidic and alkaline media.The effect is not observed for MoRuP,in which Mo prefers to occupy the pyramidal sites.In particular,CoRuP shows state-of-the-art activity,outperforming Ru_(2)P with Pt-like activity in 0.5 M H_(2)SO_(4)(η_(10)=12.3 mV;η100=52 mV;turnover frequency(TOF)=4.7 s^(-1)).It remains extraordinarily active in alkaline conditions(η10=12.9 mV;η_(100)=43.5 mV)with a TOF of 4.5 s^(-1),which is 4x higher than that of Ru_(2)P and 10x that of Pt/C.Further increase in the Co content does not lead to drastic loss of activity,especially in alkaline medium,where,for example,the TOF of Co_(1.9)Ru_(0.1)P remains comparable to that of Ru_(2)P and higher than that of Pt/C,highlighting the viability of the adopted approach to prepare cost-efficient catalysts.