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Atomically dispersed Zn-Co-N-C catalyst boosting efficient and robust oxygen reduction catalysis in acid via stabilizing Co-N bonds

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Fundamental Research 2023年第6期3卷 909-917页

作者： Feng Ma Xuan Liu Xiaoming Wang Jiashun Liang Jianyu Huang Cameron Priest Jinjia Liu Shuhong Jiao Tanyuan Wang Gang Wu Yunhui Huang Qing Li State Key Laboratory of Material Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhanHubei 430074China State Key Laboratory of Refractories and Metallurgy Institute of Advanced Materials and NanotechnologyKey Laboratory of Hubei Province for Coal Conversion and New Carbon MaterialsSchool of Chemistry and Chemical EngineeringWuhan University of Science and TechnologyWuhan 430081China Clean Nano Energy Center State Key Laboratory of Metastable Materials Science and TechnologyYanshan UniversityQinhuangdao 066004China Department of Chemical and Biological Engineering University at BuffaloThe State University of New YorkBuffaloNY 14260United States State Key Laboratory of Coal Conversion Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001China National Energy Center for Coal to Clean Fuels Synfuels China Co.LtdHuairou DistrictBeijing 101400China Department of Materials Science and Engineering Key Laboratory of Materials for Energy Conversion Chinese Academy of Science(CAS)University of Science and Technology of ChinaHefei 230026China Department of Chemistry and Key Laboratory for Preparation and Application of Ordered structural Materials of Guangdong Province Shantou UniversityShantou 515063China

Transition metal supported N-doped carbon(M-N-C)catalysts for oxygen reduction reaction(ORR)are viewed as the promising candidate to replace Pt-group metal(PGM)for proton exchange membrane fuel cells(PEMFCs).However,the stability of M-N-C is extremely challenging due to the demetalation,H_(2)O_(2)attack,etc.in the strongly oxidative conditions of PEMFCs.In this study,we demonstrate the universal effect of Zn on promoting the stability of atomically dispersed M-Nx/C(M=Co,Fe,Mn)catalysts and the enhancement mechanism is unveiled for the first time.The best-performing dual-metal-site Zn-Co-N-C catalyst exhibits a high half-wave potential(E1/2)value of 0.81 V vs.reversible hydrogen electrode(RHE)in acid and outstanding durability with no activity decay after 15,000 accelerated degradation test(ADT)cycles at 60℃,surpassing most reported Co-based PGM-free catalysts in acid media.For comparison,the Co-N-C in the absence of Zn suffers from a rapid degradation after ADT due to the demetalation and higher H_(2)O_(2)yield.X-ray adsorption spectroscopy(XAS)and density functional theory(DFT)calculations suggest the more negative formation energy(by 1.2 eV)and increased charge transfer of Zn-Co dual-site structure compared to Co-N-C could strength the Co-N bonds against the demetalation and the optimized d-band center accounts for the improved ORR kinetics.

关键词： Electrocatalysis Oxygen reduction reaction Non-noble metal catalysts Metal-nitrogen carbon catalysts Demetalation structural stability

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A GENERALIZED LIPSCHITZ SHADOWING PROPERTY FOR FLOWS

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Acta Mathematica Scientia 2023年第1期43卷 259-288页

作者：韩波 Manseob LEE LMIB of the Ministry of Education School of Mathematical SciencesBeihang UniversityBeijing100191China Department of Marketing Big Data and Mathematics Mokwon UniversityDaejeon35349Korea

In this paper,we define a generalized Lipschitz shadowing property for flows and prove that a flowΦgenerated by a C1vector field X on a closed Riemannian manifold M has this generalized Lipschitz shadowing property i... 详细信息

关键词： flow Perron property hyperbolicity generalized Lipschitz shadowing property structural stability

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支柱策略增强离子传输和结构稳定性的KVPO4F用于超稳定的钾离子电池正极

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Science Bulletin 2023年第6期68卷 593-602,M0004页

作者：赵敬秦棪阳李龙吴虎贾鑫朱小龙赵洪洋苏亚琼丁书江 School of Chemistry University Engineering Research Center of Shaanxi ProvinceEngineering Research Center of Energy Storage Materials and Devices(Ministry of Education)Xi’an Jiaotong UniversityXi’an 710049China

近年来,由于丰富的钾资源储量和低廉的价格,钾离子电池在大规模储能领域表现出极大的应用前景.开发具有高安全性、高能量密度、低成本、长寿命的正极材料是推动钾离子电池实用化的关键.KVPO4F(KVPF)因其工作电压高、能量密度高、热稳定... 详细信息

近年来,由于丰富的钾资源储量和低廉的价格,钾离子电池在大规模储能领域表现出极大的应用前景.开发具有高安全性、高能量密度、低成本、长寿命的正极材料是推动钾离子电池实用化的关键.KVPO4F(KVPF)因其工作电压高、能量密度高、热稳定性好,被认为是一种很有前途的钾离子电池正极材料.然而,由于大半径的钾离子反复脱出/嵌入导致较慢的动力学和大的体积变化,从而影响材料循环稳定性.本文通过将大半径铯离子引入KVPF结构中的“支柱”策略,可有效提高材料的离子传导特性,并改善充放电过程中材料的结构稳定性,从而实现铯掺杂的KVPF正极优异的储钾性能.同时,高循环稳定性的KVPF//石墨全电池也展示了其在钾离子电池中巨大的实际应用潜力.

关键词： Ion transport structural stability KVPO4F Cs-substitution Stable potassium-ion batteries

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结构设计稳定T2型富锂层状正极氧化物电极材料中的阴阳离子氧化还原活性

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Science Bulletin 2022年第4期67卷 381-388,M0004页

作者：曹鑫李海峰乔羽贾敏 Hirokazu Kitaura 张佳楠何平 Jordi Cabana 周豪慎 Energy Technology Research Institute National Institute of Advanced Industrial Science and Technology(AIST)Tsukuba 305-8568Japan Department of Chemistry University of Illinois at ChicagoChicagoIL 60607USA Center of Energy Storage Materials&Technology College of Engineering and Applied SciencesJiangsu Key Laboratory of Artificial Functional MaterialsNational Laboratory of Solid State Microstructuresand Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China Graduate School of System and Information Engineering University of TsukubaTsukuba 305-8573Japan College of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001China

得益于阴离子氧化还原反应的引入,富锂材料具有较高的输出容量而被认为是下一代高能量密度电池正极材料的选择之一.然而氧相关的阴离子氧化还原反应的利用常常伴随着不可逆的晶格氧析出和严重的结构畸变.此外,由于复杂的阴阳离子氧化还... 详细信息

得益于阴离子氧化还原反应的引入,富锂材料具有较高的输出容量而被认为是下一代高能量密度电池正极材料的选择之一.然而氧相关的阴离子氧化还原反应的利用常常伴随着不可逆的晶格氧析出和严重的结构畸变.此外,由于复杂的阴阳离子氧化还原反应,使得富锂材料的电荷补偿机理也需要进一步澄清.本文报道了一种T2型Li_(0.72)[Li_(0.12)Ni_(0.36)Mn_(0.52)]O_(2)正极材料.研究发现,与其他典型的富锂层状正极不同,其具有不同于传统富锂材料的四面体碱金属配位环境与ABB′A′氧堆垛顺序.得益于其良好的结构稳定性和可逆的锂离子脱嵌过程,层状T2型正极材料具有良好的电化学稳定性,在较长的循环中具有较少的容量衰减和电压下降.研究人员通过详细的光谱表征,不仅标定了复杂的阴离子氧化还原行为,而且预估了相应的阳离子/阴离子氧化还原反应对应的电化学容量,这进一步阐明具有复杂氧化还原行为材料的电荷补偿机理.

关键词： Cathode materials Layered oxides Voltage decay Lattice oxygen release structural stability

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Synthesis,characterization and experimental investigation of Cu-BTC as CO_2 adsorbent from flue gas

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Journal of Environmental Sciences 2012年第4期24卷 640-644页

作者： Jiangkun Xie Naiqiang Yan Zan Qu Shijian Yang School of Environmental Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Porous Cu-BTC material was synthesized by the solvothermal method. Powder X-ray diffraction （PXRD） was used to test the phase purity of the synthesized material and investigate its structural stability under the influence of flue gas components. The thermal stability of the material was determined through thermal gravimetric （TG） analysis. Scanning electron microscopy （SEM） was employed to study the microstructure of the material. Cu-BTC was demonstrated not only to have high CO2 adsorption capacity but also good selectivity of CO2 over N2 by means of packed bed tests. The adsorption capacity of Cu-BTC for CO2 was about 69 mL/g at 22℃. The influence of the main flue gas components on the CO2 capacity of the material were discussed as well.

关键词： Cu-BTC CO2 capture structural stability influence of flue gas components

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structural optimization and segregation behavior of quaternary alloy nanoparticles based on simulated annealing algorithm

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Chinese Physics B 2016年第5期25卷 151-158页

作者：陆欣泽邵桂芳许两有刘暾东文玉华 Department of Physics Xiamen University Department of Automation Xiamen University

Alloy nanoparticles exhibit higher catalytic activity than monometallic nanoparticles, and their stable structures are of importance to their applications. We employ the simulated annealing algorithm to systematically explore the stable structure and segregation behavior of tetrahexahedral Pt–Pd–Cu–Au quaternary alloy nanoparticles. Three alloy nanoparticles consisting of 443 atoms, 1417 atoms, and 3285 atoms are considered and compared. The preferred positions of atoms in the nanoparticles are analyzed. The simulation results reveal that Cu and Au atoms tend to occupy the surface, Pt atoms preferentially occupy the middle layers, and Pd atoms tend to segregate to the inner layers. Furthermore, Au atoms present stronger surface segregation than Cu ones. This study provides a fundamental understanding on the structural features and segregation phenomena of multi-metallic nanoparticles.

关键词： alloy nanoparticle simulated annealing algorithm structural stability segregation

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Fast and highly reversible Na^(+)intercalation/extraction in Zn/Mg dual-doped P2-Na_(0.67)MnO_(2)cathode material for high-performance Na-ion batteries

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Nano Research 2021年第10期14卷 3531-3537页

作者： Xiaoqin Huang Deli Li Haijian Huang Xiao Jiang Zeheng Yang Weixin Zhang School of Chemistry and Chemical Engineering Hefei University of TechnologyHefei 230009China Anhui Key Laboratory of Controllable Chemical Reaction&Material Chemical Engineering Hefei 230009China

P2-type layered Na_(0.67)MnO_(2)has been considered to be a promising candidate cathode material for sodium ion batteries.Nevertheless,the undesired phase transitions during operation and the large Na^(+)radius induced sluggish ion diffusion remain the stumbling blocks to realize its high performance.Herein,we propose a Zn/Mg co-doping strategy,which is proved to have bifunctional effects.First,relative to the pristine P2-Na_(0.67)MnO_(2)and the single-ion(Zn/Mg)doped samples,the Zn/Mg dual-doped P2-Na_(0.67)MnO_(2)demonstrates a lower Mn^(3+)/Mn^(4+)ratio and a higher lattice O content,which facilitate the structural stability of the cathode material.More intriguingly,the Zn/Mg co-doping gives rise to enlarged interplanar spacing,which provides spacious ion diffusion channels for fast Na^(+)intercalation/extraction.As a result,the Zn/Mg dual-doped sample exhibits a high Na^(+)diffusion coefficient and a solid-solution reaction during charge/discharge,with a cell volume change determined to be only 0.55%.Taking advantages of the above favorable features,the Zn/Mg dual-doped P2-Na_(0.67)MnO_(2)demonstrates a high rate performance with 67.2 mAh·g^(-1)delivered at 10 C and a decent cycling stability with a capacity retention of 93.8%achieved at 1 C after 100 cycles.This work introduces the Zn/Mg co-doping strategy to simultaneously improve the cycling stability and rate capability of P2-Na_(0.67)MnO_(2),which may offer a promising avenue for further performance enhancement of the layered Na-ion batteries cathode materials.

关键词： Na-ion batteries cathode materials co-doping Na-ion diffusion structural stability

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Studies on the stability of On-top Al_(13)I_n^m(n=1～12,m=–1,0,+1) Clusters

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Chinese Journal of structural Chemistry 2007年第1期26卷 84-90页

作者：杨峰彭平李贵发韩绍昌 School of Material Science&Engineering Hunan University

Energetic and electronic structures of the on-top Al13In^m （n = 1 - 1 2, m = -1, 0, ＋1） clusters have been investigated by employing a first-principles pseudo-potential plane wave method. Several parameters such as binding energies, second differences of energy and vertical-electron detachment energies have been adopted to characterize and evaluate the structure stability of Al13In^- （n= 1 - 12） clusters. The optimized models show that the Al13 moieties in the clusters can not retain the original regular icosahedron structure. Results from binding energy and second difference of energy show that Al13In and Al13In^- clusters with even n are more stable than those with odd n in contrast with Al13In^＋ clusters. The calculation of vertical-electron detachment energies （VDE） of Al13In clusters indicates that Al13In and Al13In^- clusters with even n are closer to the closed shell of the Jellium model. Further analysis of electron density of states and electron density differences reveals that the enhanced stability of AI13In^- clusters is not only associated with the closed shell of valence electrons but also with the bonding type between I and associated AI atoms.

关键词： Al13In^m dusters structural stability first-principles calculation

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A First-principles Calculation of Structures and stability of Al_(13)I Cluster

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Chinese Journal of structural Chemistry 2006年第2期25卷 232-239页

作者： LI Gui-Fa PENG Ping YANG Feng HAN Shao-Chang School of Materials Science ＆ Engineering Hunan University Changsha 410082 China

Using first-principles pseudo-potential plane wave method, the energetics, geometrical and electronic structures of three Al13I cluster isomers were calculated. The calculation results of the binding energy indicate Al13I cluster is more stable than Al13 cluster although its electrons are not a magic number as in Alia cluster, and among Al13I cluster isomers the ＂Bridge＂ structure is the most stable, the second is the ＂Ontop＂ structure, and the worst is the ＂Hollow＂ structure. By analyzing the geometrical structures of Al13I cluster isomers, it is found that after I atom and Al13 cluster combine the geometrical structures of Al13 moieties are changed besides Al13I Hollow cluster, in which the Alia moiety is still a regular icosahedron. For Al13I Ontop cluster, the Al13 moiety has a shrinking trend to I, whereas in Al13I Bridge cluster it is distorted. Mulliken population analysis shows for the interaction of electrons between Al-I atoms in Al13I cluster not only there exists an ionic bonding but there is a covalent bonding. Part of electrons in the Alia cluster transfer to I as Al13 cluster and I atom combine. The order of the strength of covalent bonding between Al13 moiety and I in Al13I cluster isomers is Al13IBridge〉Al13IHollow〉Al13I Ontop. Further analysis of electric structures of Al13 and Al13I clusters indicates a higher stability of Al13I cluster than Al13 cluster can be attributed to the s-p hybridization of 3s and 3p electrons of Al in Al13 moiety induced by 1 doped, which leads to fewer electrons N（EF） at EF in Al13I and a larger energy gap △EH-L between HOMO and LUMO levels in Al13I cluster. The distinguish of structural stability of Al13I cluster isomers mainly originates from their different magnitudes .in decrease of N（EF） and increase of △EH-L relative to Al13 cluster. The fewest N（EF） and the largest △EH-L are responsible for the high stability of Al13I Bridge cluster.

关键词： Al13I cluster structural stability electronic structure,pseudo-potential plane-wave method

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First-principles-aided thermodynamic modeling of transition-metal heterogeneous catalysts:A review

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Green Energy & Environment 2020年第3期5卷 286-302页

作者： Haoxiang Xu Daojian Cheng State Key Laboratory of Organic-Inorganic Composites and Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical TechnologyBeijing100029China

Over the past decade,the first-principles-aided thermodynamic models have become standard theoretical tools in research on structural stability and evolution of transition-metal heterogeneous catalysts under reaction environment.Advances in first-principles-aided thermodynamic models mean it is now possible to enable the operando computational modeling,which provides a deep insight into mechanism behind structural stability and evolution,and paves the way for high-through screening for promising transition-metal heterogeneous catalysts.Here,we briefly review the framework and foundation of first-principles-aided thermodynamic models and highlight its contribution to stability analysis on catalysts and identification of reaction-induced structural evolution of catalyst under reaction environment.The present review is helpful for understanding the ongoing developments of first-principles-aided thermodynamic models,which can be employed to screen high-stability catalysts and predict their structural reconstruction in future rational catalyst design.

关键词： First-principles calculation Thermodynamic principle Transition metal catalyst structural stability structural evolution

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