Two-dimensional(2D)MXene and single-atom(SA)catalysts are two frontier research fields in catalysis.2D materials with unique geometric and electronic structures can modulate the catalytic performance of supported SAs,...Two-dimensional(2D)MXene and single-atom(SA)catalysts are two frontier research fields in catalysis.2D materials with unique geometric and electronic structures can modulate the catalytic performance of supported SAs,which,in turn,affect the intrinsic activity of 2D materials.Density functional theory calculations were used to systematically explore the potential of O-terminated V2C MXene(V_(2)CO_(2))-supported transition metal(TM)SAs,including a series of 3d,4d,and 5d metals,as oxygen reduction reaction(ORR)and hydrogen oxidation reaction(HOR)catalysts.The combination of TM SAs and V_(2)CO_(2)changes their electronic structure and enriches the active sites,and consequently regulates the intermediate adsorption energy and catalytic activity for ORR and HOR.Among the investigated TM-V_(2)CO_(2)models,Sc-,Mn-,Rh-,and PtMCCh showed high ORR activity,while Sc-,Ti-,V-,Cr-,and Mn-V_(2)CO_(2)exhibited high HOR activity.Specifically,Mn-and Sc-V_(2)CO_(2)are expected to serve as highly efficient and cost-effective bifunctional catalysts for fuel cells because of their high catalytic activity and stability.This work provides theoretical guidance for the rational design of efficient ORR and HOR bifunctional catalysts.展开更多
Highly efficient and stable oxygen reduction reaction(ORR)electrocatalysts are remarkably important but challenging for advancing the large-scale commercialization of practical proton exchange membrane fuel cells(PEMF...Highly efficient and stable oxygen reduction reaction(ORR)electrocatalysts are remarkably important but challenging for advancing the large-scale commercialization of practical proton exchange membrane fuel cells(PEMFCs).In this work,we report that the introduction of interstitial hydrogen atoms into PtPd nanotubes can significantly promote ORR performance without scarifying the durability.The enhanced mass activity was 8.8 times higher than that of commercial Pt/C.The accelerated durability test showed negligible activity attenuation after 30,000 cycles.Additionally,H2/O2 fuel cell tests further verified the excellent activity of PtPd-H nanotubes with a maximum power density of 1.32 W·cm^(−2),superior to that of commercial Pt/C(1.16 W·cm^(−2)).Density functional theory calculations demonstrated the incorporation of hydrogen atoms gives rise to the broadening of Pt d-band and the downshift of d-band center,which consequently leads to the weaker intermediates binding and enhanced ORR activity.展开更多
Achieving stable surface structures of metal catalysts is an extreme challenge for obtaining long-term durability and meeting industrial application requirements.We report a new class of metal catalyst,Pt-rich PtCu he...Achieving stable surface structures of metal catalysts is an extreme challenge for obtaining long-term durability and meeting industrial application requirements.We report a new class of metal catalyst,Pt-rich PtCu heteroatom subnanoclusters epitaxially grown on an octahedral PtCu alloy/Pt skin matrix(PtCu1.60),for the oxygen reduction reaction(ORR)in an acid electrolyte.The PtCu1.60/C exhibits an 8.9-fold enhanced mass activity(1.42 A·mgPt^(−1))over that of commercial Pt/C(0.16 A·mgPt^(−1)).The PtCu1.60/C exhibits 140,000 cycles durability without activity decline and surface PtCu cluster stability owing to unique structure derived from the matrix and epitaxial growth pattern,which effectively prevents the agglomeration of clusters and loss of near-surface active sites.Structure characterization and theoretical calculations confirm that Pt-rich PtCu clusters favor ORR activity and thermodynamic stability.In room-temperature polymer electrolyte membrane fuel cells,the PtCu1.60/C shows enhanced performance and delivers a power density of 154.1/318.8 mW·cm^(−2)and 100 h/50 h durability without current density decay in an air/O_(2)feedstock.展开更多
Proton exchange membrane fuel cells(PEMFCs)have received a sustained world-wide attention owing to their promising applications based on clean energy.However,their widespread applications are still restricted by the s...Proton exchange membrane fuel cells(PEMFCs)have received a sustained world-wide attention owing to their promising applications based on clean energy.However,their widespread applications are still restricted by the sluggish oxygen reduction reaction(ORR)process.Over the past decades,significant efforts have been devoted to developing efficient ORR catalysts,which have been summarized in numerous previous reviews.Unfortunately,most of them mainly focused on ORR activity on the rotating disk electrode(RDE)level,which cannot truly represent the performance in real applications.Developing and showcasing efficient catalysts evaluated at the membrane electrode assembly(MEA)level is of vital importance.In this review,we first briefly showcased the recent development of ORR catalysts and then put more emphasis on the discussion of designing efficient catalysts at MEA and full-cell level,aiming to help stimulate more attention on their practical applications.展开更多
Nanocarbons are of progressively increasing importance in energy electrocatalysis, including oxygen reduction, oxygen evolution, hydrogen evolution, COreduction, etc. Precious-metal-free or metal-free nanocarbon-based...Nanocarbons are of progressively increasing importance in energy electrocatalysis, including oxygen reduction, oxygen evolution, hydrogen evolution, COreduction, etc. Precious-metal-free or metal-free nanocarbon-based electrocatalysts have been revealed to potentially have effective activity and remarkable durability, which is promising to replace precious metals in some important energy technologies,such as fuel cells, metal–air batteries, and water splitting. In this review, rather than overviewing recent progress completely, we aim to give an in-depth digestion of present achievements, focusing on the different roles of nanocarbons and material design principles. The multifunctionalities of nanocarbon substrates(accelerating the electron and mass transport, regulating the incorporation of active components,manipulating electron structures, generating confinement effects, assembly into 3 D free-standing electrodes) and the intrinsic activity of nanocarbon catalysts(multi-heteroatom doping, hierarchical structure,topological defects) are discussed systematically, with perspectives on the further research in this rising research field. This review is inspiring for more insights and methodical research in mechanism understanding, material design, and device optimization, leading to a targeted and high-efficiency development of energy electrocatalysis.展开更多
过渡金属间隙化合物(transition metal interstitial compounds,TMICs)具有独特的电子结构、高导电性、优异的化学稳定性,可作为可再生能源转化反应中Pt基催化剂的替代电催化剂.从这个角度出发,综述了TMICs在合成和电催化性能方面的研...过渡金属间隙化合物(transition metal interstitial compounds,TMICs)具有独特的电子结构、高导电性、优异的化学稳定性,可作为可再生能源转化反应中Pt基催化剂的替代电催化剂.从这个角度出发,综述了TMICs在合成和电催化性能方面的研究进展,主要归纳了TMICs在析氢反应、析氧反应、氧还原反应、直接液体燃料电池阳极反应等方面的催化性能.此外,简述了TMICs电催化剂实际应用于能量转换设备中的潜力,这对开发高效稳定的电化学能量转换设备具有指导意义.展开更多
内燃机为了顺应21世纪下半叶实现碳中和的趋势避免被淘汰,必须在运行时实现CO_(2)的零排放。另外,由于发动机的最高有效热效率明显低于电动车或燃料电池车,这会使消费者逐渐疏远发动机车。1948年,F. M. Lewis发明的氩气(Ar)闭循环氢气...内燃机为了顺应21世纪下半叶实现碳中和的趋势避免被淘汰,必须在运行时实现CO_(2)的零排放。另外,由于发动机的最高有效热效率明显低于电动车或燃料电池车,这会使消费者逐渐疏远发动机车。1948年,F. M. Lewis发明的氩气(Ar)闭循环氢气发动机重新回到了人们的视野中。这是因为此种发动机不排出CO_(2),而且Ar的比热比高于空气,以Ar为工质的发动机的热效率可以有较大提升甚至匹敌电动车或燃料电池车。本文比较详细地介绍了这种发动机的原理、发展史、存在的优缺点以及研究动向和研发课题。同时也介绍了作者近年来的部分研究成果,探讨了Ar闭循环氢气发动机与氢气及燃料电池车的关系及其发展前景。展开更多
文摘Two-dimensional(2D)MXene and single-atom(SA)catalysts are two frontier research fields in catalysis.2D materials with unique geometric and electronic structures can modulate the catalytic performance of supported SAs,which,in turn,affect the intrinsic activity of 2D materials.Density functional theory calculations were used to systematically explore the potential of O-terminated V2C MXene(V_(2)CO_(2))-supported transition metal(TM)SAs,including a series of 3d,4d,and 5d metals,as oxygen reduction reaction(ORR)and hydrogen oxidation reaction(HOR)catalysts.The combination of TM SAs and V_(2)CO_(2)changes their electronic structure and enriches the active sites,and consequently regulates the intermediate adsorption energy and catalytic activity for ORR and HOR.Among the investigated TM-V_(2)CO_(2)models,Sc-,Mn-,Rh-,and PtMCCh showed high ORR activity,while Sc-,Ti-,V-,Cr-,and Mn-V_(2)CO_(2)exhibited high HOR activity.Specifically,Mn-and Sc-V_(2)CO_(2)are expected to serve as highly efficient and cost-effective bifunctional catalysts for fuel cells because of their high catalytic activity and stability.This work provides theoretical guidance for the rational design of efficient ORR and HOR bifunctional catalysts.
基金supported by the National Key R&D Program of China(Nos.2017YFA0700104 and 2018YFA0702001)the National Natural Science Foundation of China(No.21871238)+2 种基金the Fundamental Research Funds for the Central Universities(No.WK2060000016)the Youth Innovation Promotion Association of the Chinese Academy of Science(No.2018494)the Hefei National Laboratory for Physical Sciences at the Microscale(No.KF2020107).
文摘Highly efficient and stable oxygen reduction reaction(ORR)electrocatalysts are remarkably important but challenging for advancing the large-scale commercialization of practical proton exchange membrane fuel cells(PEMFCs).In this work,we report that the introduction of interstitial hydrogen atoms into PtPd nanotubes can significantly promote ORR performance without scarifying the durability.The enhanced mass activity was 8.8 times higher than that of commercial Pt/C.The accelerated durability test showed negligible activity attenuation after 30,000 cycles.Additionally,H2/O2 fuel cell tests further verified the excellent activity of PtPd-H nanotubes with a maximum power density of 1.32 W·cm^(−2),superior to that of commercial Pt/C(1.16 W·cm^(−2)).Density functional theory calculations demonstrated the incorporation of hydrogen atoms gives rise to the broadening of Pt d-band and the downshift of d-band center,which consequently leads to the weaker intermediates binding and enhanced ORR activity.
基金supported by the National Natural Science Foundation of China(Nos.21571038,21903001,and 22035004)the National Key R&D Program of China(No.2017YFA0700101)+5 种基金Education Department of Guizhou Province(No.2021312)Foundation of Guizhou Province(No.2019-5666)Science Foundation for Aftergraduated Students of Guizhou Province(No.YJSKYJJ2021020)National Science Foundation of Anhui Province(No.1908085QB58)State Key Laboratory of Physical Chemistry of Solid Surfaces(Xiamen University,No.202009)the Open Fund of the Key Lab of Organic Optoelectronics&Molecular Engineering(Tsinghua University).
文摘Achieving stable surface structures of metal catalysts is an extreme challenge for obtaining long-term durability and meeting industrial application requirements.We report a new class of metal catalyst,Pt-rich PtCu heteroatom subnanoclusters epitaxially grown on an octahedral PtCu alloy/Pt skin matrix(PtCu1.60),for the oxygen reduction reaction(ORR)in an acid electrolyte.The PtCu1.60/C exhibits an 8.9-fold enhanced mass activity(1.42 A·mgPt^(−1))over that of commercial Pt/C(0.16 A·mgPt^(−1)).The PtCu1.60/C exhibits 140,000 cycles durability without activity decline and surface PtCu cluster stability owing to unique structure derived from the matrix and epitaxial growth pattern,which effectively prevents the agglomeration of clusters and loss of near-surface active sites.Structure characterization and theoretical calculations confirm that Pt-rich PtCu clusters favor ORR activity and thermodynamic stability.In room-temperature polymer electrolyte membrane fuel cells,the PtCu1.60/C shows enhanced performance and delivers a power density of 154.1/318.8 mW·cm^(−2)and 100 h/50 h durability without current density decay in an air/O_(2)feedstock.
基金support by the Natural Science Foundation of Shandong Province(No.ZR202103040753)the National Natural Science Foundation of China(No.22102086).
文摘Proton exchange membrane fuel cells(PEMFCs)have received a sustained world-wide attention owing to their promising applications based on clean energy.However,their widespread applications are still restricted by the sluggish oxygen reduction reaction(ORR)process.Over the past decades,significant efforts have been devoted to developing efficient ORR catalysts,which have been summarized in numerous previous reviews.Unfortunately,most of them mainly focused on ORR activity on the rotating disk electrode(RDE)level,which cannot truly represent the performance in real applications.Developing and showcasing efficient catalysts evaluated at the membrane electrode assembly(MEA)level is of vital importance.In this review,we first briefly showcased the recent development of ORR catalysts and then put more emphasis on the discussion of designing efficient catalysts at MEA and full-cell level,aiming to help stimulate more attention on their practical applications.
基金supported by the National Key Research and Development Program (Nos. 2016YFA0202500 and 2016YFA0200102)the Natural Scientific Foundation of China (No. 21561130151)Royal Society for the award of a Newton Advanced Fellowship (Ref: NA140249)
文摘Nanocarbons are of progressively increasing importance in energy electrocatalysis, including oxygen reduction, oxygen evolution, hydrogen evolution, COreduction, etc. Precious-metal-free or metal-free nanocarbon-based electrocatalysts have been revealed to potentially have effective activity and remarkable durability, which is promising to replace precious metals in some important energy technologies,such as fuel cells, metal–air batteries, and water splitting. In this review, rather than overviewing recent progress completely, we aim to give an in-depth digestion of present achievements, focusing on the different roles of nanocarbons and material design principles. The multifunctionalities of nanocarbon substrates(accelerating the electron and mass transport, regulating the incorporation of active components,manipulating electron structures, generating confinement effects, assembly into 3 D free-standing electrodes) and the intrinsic activity of nanocarbon catalysts(multi-heteroatom doping, hierarchical structure,topological defects) are discussed systematically, with perspectives on the further research in this rising research field. This review is inspiring for more insights and methodical research in mechanism understanding, material design, and device optimization, leading to a targeted and high-efficiency development of energy electrocatalysis.
文摘过渡金属间隙化合物(transition metal interstitial compounds,TMICs)具有独特的电子结构、高导电性、优异的化学稳定性,可作为可再生能源转化反应中Pt基催化剂的替代电催化剂.从这个角度出发,综述了TMICs在合成和电催化性能方面的研究进展,主要归纳了TMICs在析氢反应、析氧反应、氧还原反应、直接液体燃料电池阳极反应等方面的催化性能.此外,简述了TMICs电催化剂实际应用于能量转换设备中的潜力,这对开发高效稳定的电化学能量转换设备具有指导意义.
文摘内燃机为了顺应21世纪下半叶实现碳中和的趋势避免被淘汰,必须在运行时实现CO_(2)的零排放。另外,由于发动机的最高有效热效率明显低于电动车或燃料电池车,这会使消费者逐渐疏远发动机车。1948年,F. M. Lewis发明的氩气(Ar)闭循环氢气发动机重新回到了人们的视野中。这是因为此种发动机不排出CO_(2),而且Ar的比热比高于空气,以Ar为工质的发动机的热效率可以有较大提升甚至匹敌电动车或燃料电池车。本文比较详细地介绍了这种发动机的原理、发展史、存在的优缺点以及研究动向和研发课题。同时也介绍了作者近年来的部分研究成果,探讨了Ar闭循环氢气发动机与氢气及燃料电池车的关系及其发展前景。
