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Fundamental Understanding of Hydrogen Evolution Reaction on Zinc Anode Surface:A First‑Principles Study

Nano-Micro Letters 2024年第6期16卷 180-191页

作者： Xiaoyu Liu Yiming Guo Fanghua Ning Yuyu Liu Siqi Shi Qian Li Jiujun Zhang Shigang Lu Jin Yi Institute for Sustainable Energy&Department of Chemistry Shanghai UniversityShanghai 200444People’s Republic of China School of Materials Science and Engineering Shanghai UniversityShanghai 200444People’s Republic of China College of Materials Science and Engineering National Engineering Research Center for Magnesium AlloysChongqing UniversityChongqing 400044People’s Republic of China

Hydrogen evolution reaction(HER)has become a key factor affecting the cycling stability of aqueous Zn-ion batteries,while the corresponding fundamental issues involving HER are still unclear.Herein,the reaction mechanisms of HER on various crystalline surfaces have been investigated by first-principle calculations based on density functional theory.It is found that the Volmer step is the ratelimiting step of HER on the Zn(002)and(100)surfaces,while,the reaction rates of HER on the Zn(101),(102)and(103)surfaces are determined by the Tafel step.Moreover,the correlation between HER activity and the generalized coordination number(CN)of Zn at the surfaces has been revealed.The relatively weaker HER activity on Zn(002)surface can be attributed to the higher CN of surface Zn atom.The atomically uneven Zn(002)surface shows significantly higher HER activity than the flat Zn(002)surface as the CN of the surface Zn atom is lowered.The CN of surface Zn atom is proposed as a key descriptor of HER activity.Tuning the CN of surface Zn atom would be a vital strategy to inhibit HER on the Zn anode surface based on the presented theoretical studies.Furthermore,this work provides a theoretical basis for the in-depth understanding of HER on the Zn surface.

关键词： Aqueous Zn-ion battery Zn anode Hydrogen evolution reaction coordination number First-principles calculation

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DEM Analysis of Single-Particle Crushing Considering the Inhomogeneity of Material Properties

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Acta Mechanica Solida Sinica 2022年第1期35卷 26-39页

作者： Tao Zhang Wenxiong Huang College of Mechanics and Materials Hohai UniversityNanjing 211100China

Crushing characteristics of single particles are the basis of granular material simulation with discrete element method(DEM).To improve the universality and precision of crushable DEM model,inhomogeneous stiffness and strength properties are introduced into the bonded particle method,with which the Weibull distribution and size effect of particle strength can be reproduced without deleting elementary balls.The issues of particle strength and carrying capacity under complex contact conditions are investigated in this work by symmetric loading tests,asymmetric loading tests,and ball-ball loading tests.Results of numerical experiments indicate that particle carrying capacity is significantly influenced by coordination numbers,the symmetry of contact points,as well as the relative size of its neighbors.Contact conditions also show impact on single-particle crushing categories and the origin position of inner particle cracks.The existing stress indexes and assumptions of particle crushing criterion are proved to be inappropriate for general loading cases.Both the inherent inhomogeneity and contact conditions of particles should be taken into consideration in the simulation of granular materials.

关键词： Bonded particle method Inhomogeneous properties Size effect coordination number Symmetry Relative size

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Achieving highly selective electrochemical CO_(2) reduction to C_(2)H_(4) on Cu nanosheets

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Journal of Energy Chemistry 2023年第4期79卷 312-320页

作者： Huan Xie Ruikuan Xie Zhiyuan Zhang Yongyu Pang Yuting Luo Jiong Li Bilu Liu Maria-Magdalena Titirici Guoliang Chai State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002FujianChina Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources International Innovation Center for Forest Chemicals and MaterialsCollege of Materials Science and EngineeringNanjing Forestry UniversityNanjing 210037JiangsuChina Shenzhen Geim Graphene Center(SGC) Tsinghua-Berkeley Shenzhen Institute(TBSI)and Tsinghua Shenzhen International Graduate School(TSIGS)Tsinghua UniversityShenzhen 518055GuangdongChina School of Chemical Science University of Chinese Academy of SciencesBeijing 100049China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China Department of Chemical Engineering Imperial College LondonSW72AZUK

The conversion of CO_(2)into value-added chemicals coupled with the storage of intermittent renewable electricity is attractive.CuO nanosheets with an average size and thickness of~30 and~20 nm have been developed,which are in situ reduced into Cu nanosheets during electrochemical CO_(2)reduction reaction(ECO_(2)RR).The derived Cu nanosheets demonstrate much higher selectivity for C2H4production than commercial CuO derived Cu powder,with an optimum Faradaic efficiency of 56.2%and a partial current density of C_(2)H_(4)as large as 171.0 mA cm^(-2)in a gas diffusion flow cell.The operando attenuated total reflectance-Fourier transform infrared spectra measurements and density functional theory simulations illustrate that the high activity and selectivity of Cu nanosheets originate from the edge sites on Cu nanosheets with a coordinate number around 5(4–6),which facilitates the formation of^(*)CHO rather than^(*)COH intermediate,meanwhile boosting the C-C coupling reaction of^(*)CO and^(*)CHO intermediates,which are the critical steps for C_(2)H_(4)formation.

关键词： Electrochemical CO_(2)reduction Cu nanosheets C_(2)H_(4) High selectivity coordination number

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Boosting Efficient Ammonia Synthesis over Atomically Dispersed Co-Based Catalyst via the Modulation of Geometric and Electronic Structures

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CCS Chemistry 2022年第5期4卷 1758-1769页

作者： Yanliang Zhou Congying Wang Xuanbei Peng Tianhua Zhang Xiuyun Wang Yafei Jiang Haifeng Qi Lirong Zheng Jianxin Lin Lilong Jiang National Engineering Research Center of Chemical Fertilizer Catalyst Fuzhou UniversityFuzhouFujian 350002 Department of Chemistry Southern University of Science and TechnologyShenzhen 518055 Dalian Institute of Chemical Physics Chinese Academy of SciencesDalian 116023 Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049

Ammonia(NH_(3))synthesis at mild conditions is of great significance,while the significant bottleneck of this process is the activation of N_(2) to realize the desired NH_(3) synthesis performance,which requires deep insight and rational design of active sites at the atomic level.Here,were synthesized atomically dispersed Co-based catalysts with different Co-N coordination numbers(CNs)to explore the coordination-sensitive NH_(3) synthesis reaction for the first time.Our studies showed that Co-based catalysts increased the NH_(3) synthesis rate gradually with a decrease in CN.The Co-N_(2) catalyst exhibited the highest NH_(3) synthesis rate of 85.3 mmol gCo^(−1) h^(−1) at 300℃ and 1 MPa,which outperformed most of the previously reported Co-based catalysts.Various characterizations and theoretical calculations demonstrated that atomically dispersed Co catalyst with low CN could generate more unoccupied Co 3d charges and tetrahedral cobalt(Ⅱ)sites.The unoccupied Co 3d charge,in turn,promoted the electron donation from the Co active center to the antibonding π-orbital(π*)of N_(2) and expedites N_(2) hydrogenation.Furthermore,the Co-N_(2) catalyst with more tetrahedral cobalt(II)sites could effectively facilitate the desorption of N-containing intermediate species(such as*NH_(3) and*N_(2)H_(4))to obtain a high NH_(3) synthesis rate.

关键词： ammonia synthesis coordination number electron transfer geometric structure intermediate species

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碳酸物种和氯离子对生物磷灰石磷酸钙成核的影响

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Science China Materials 2023年第7期66卷 2872-2884页

作者：陈红威王俊霖 A.E.Willaims-Jones 朱琴郑利锋赵晨晨刘子腾徐伟高魏海珍郭琳马晶 Key Laboratory of Mesoscopic Chemistry of Ministry of Education School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China State Key Laboratory for Mineral Deposits Research Department of Earth Sciences and EngineeringNanjing UniversityNanjing 210023China Department of Earth and Planetary Sciences McGill UniversityMontreal H3A 0E8Canada

磷灰石是骨骼和牙齿等生物硬组织的主要无机成分,对脊椎动物至关重要.生物系统的体液中普遍存在碳酸物种和Cl^(-)离子,了解这些阴离子对生物磷灰石成核过程的影响有助于解释生物矿化的控制作用.理论研究表明,Ca-O配位数在CaP成核和CaP... 详细信息

磷灰石是骨骼和牙齿等生物硬组织的主要无机成分,对脊椎动物至关重要.生物系统的体液中普遍存在碳酸物种和Cl^(-)离子,了解这些阴离子对生物磷灰石成核过程的影响有助于解释生物矿化的控制作用.理论研究表明,Ca-O配位数在CaP成核和CaP与添加剂的界面相互作用中是一个重要描述符.CaP团簇最外层的Ca^(2+)离子能够通过静电作用吸引碳酸物种和Cl^(-)离子,从而促进CaP相的形成.在碳酸物种和Cl^(-)离子存在的情况下,钙磷石(DCPD)可以转化为羟基磷灰石(HA).平衡氧同位素分馏和振动光谱分析结果表明,Cl^(-)离子掺杂的B型HA是最有可能的生物磷灰石.上述结果可以指导阴离子掺杂的具有生物功能的磷灰石材料的合成.

关键词： calcium phosphate Cl^(-)ion carbonate species coordination number surface energy simulated body fluid solution

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A numerical analysis of the shear behavior of granular soil with fines

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Particuology 2015年第4期13卷 160-172页

作者： Beibing Dai Jun Yang Xiaodong Luo Research Centre of Geotechnical Engineering and Information Technology Sun Yat-sen University Department of Civil Engineering The University of Hong Kong

Shear behavior of granular soil with fines is investigated using the discrete element method （DEM） and particle arrangements and inter-particle contacts during shear are examined. The DEM simulation reveals that fine particles play a vital role in the overall response of granular soil to shearing. The occurrence of liquefaction and temporary reduction of strength is ascribed mainly to the loss of support from the fine particle contacts （S-S） and fine particle-to-large particle contacts （S-L） as a consequence of the removal of fine particles from the load-carrying skeleton. The dilative strain-hardening response following the strain-softening response is associated with the migration of fine particles back into the load-carrying skeleton, which is thought to enhance the stiffness of the soil skeleton. During shear, the unit normal vector of the large particle-to-large particle （L-L） contact has the strongest fabric anisotropy, and the S-S contact unit normal vector possesses the weakest anisotropy, suggesting that the large particles play a dominant role in carrying the shear load. It is also found that, during shear, fine particles are prone to rolling at contacts while the large particles are prone to sliding, mainly at the S-L and L-L contacts.

关键词： Granular soil Fine particle Shear behavior Discrete element method Fabric anisotropy coordination number

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Random packing of tetrahedral particles using the polyhedral discrete element method

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Particuology 2015年第6期13卷 109-117页

作者： Shiwei Zhao Xiaowen Zhou Wenhui Liu Chengguang Lai School of Civil Engineering and Transportation South China University of Technology Guangzhou 510640 China State Key Laboratory of Subtropical Building Science Guangzhou 510640 China Key Laboratory of Water Cycle and Water Security in Southern China of Guangdong Higher Education Institutes Cuangzhou 510275 China

The random packing of tetrahedral particles is studied by applying the discrete element method （DEM）, which simulates the effects of friction, height ratio, and eccentricity. The model predictions are ana- lyzed in terms of packing density and coordination number （CN）. It is demonstrated that friction has the maximal effect on packing density and mean CN among the three parameters. The packing den- sity of the regular tetrahedron is 0.71 when extrapolated to a zero friction effect. The shape effects of height ratio and eccentricity show that the regular tetrahedron has the highest packing density in the family of tetrahedra, which is consistent with what has been reported in the literature. Compared with geometry-based packing algorithms, the DEM packing density is much lower. This demonstrates that the inter-particle mechanical forces have a considerable effect on packing. The DEM results agree with the published experimental results, indicating that the polyhedral DEM model is suitable for simulating the random packing of tetrahedral particles.

关键词： Discrete element method Random packing Tetrahedral particle coordination number Packing density

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Glassy behaviour of random field Ising spins on Bethe lattice in external magnetic field

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Chinese Physics B 2011年第6期20卷 416-425页

作者： Khalid Bannora Galal Ismail Wafaa Hassan Mathematics Department Faculty of Science Zagazig University Mathematics and Physics Department Faculty of Engineering Port Said Branch of Suez Canal University

The thermodynamics and the phase diagram of random field Ising model （RFIM） on Bethe lattice are studied by using a replica trick. This lattice is placed in an external magnetic field （B）. A Gaussian distribution of random field （hi） with zero mean and variance （hi2 = H2RF is considered. The free-energy （F）, the magnetization （M） and the order parameter （q） are investigated for several values of coordination number （z）. The phase diagram shows several interesting behaviours and presents tricritical point at critical temperature Tc = J/k and when HRF = 0 for finite z. The free-energy （F） values increase as T increases for different intensities of random field （HRE） and finite z. The internal energy （U） has a similar behaviour to that obtained from the Monte Carlo simulations. The ground state of magnetization decreases as the intensity of random field HRF increases, The ferromagnetic （FM） paramagnetic （PM） phase boundary is clearly observed only when z →∞. While FM PM-spin glass （SG） phase boundaries are present for finite z. The magnetic susceptibility （X） shows a sharp cusp at Tc in a small random field for finite z and rounded different peaks on increasing HRF.

关键词： random field replica trick coordination number order parameter susceptibility and phase diagram

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Ytterbium coordination Polymer with Four Different coordination numbers: The First Structural Characterization of Lanthanide Phthalate Complex

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Chinese Journal of Chemistry 2002年第9期20卷 813-815页

作者：万永红金林培王科志 Department of Chemistry Beijing Normal University Beijing 100875 China

The novel ytterbium coordination polymer is a two dimensional framework in which the central metal ions have four different coordination numbers and form four kinds of coordination polyhedra. The four kinds of coordi... 详细信息

关键词： ytterbium phthalate complex coordination polymer coordination number

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Hybridization： A Chemical Bonding Nature of Atoms

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Chinese Journal of Chemistry 2017年第9期35卷 1452-1458页

作者： Dongfeng Xue Congting Sun Xiaoyan Chen State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China

Both the bonding mode and geometry can serve as the chemical bonding nature of central cation, which is essentially determined by the atomic orbital-hybridization. In this work, we focus on the possible chemical bonding scheme of central cations on the basis of a quantitative analysis of electron domain of an atom. Starting from the hybridization of outer atomic orbitals that are occupied by valence electrons, we studied the possible orbital hybridization scheme of atoms in the periodic table and the corresponding coordination number as well as possible molecular geometries. According to distinct hybrid orbital sets, the chemical bonding of central cations can be classified into three typical types, resulting in the cations with a variety of coordination numbers ranging from 2 to 16. Owing to different hybridization modes, the highest coordination number of cations in IA and IIA groups is larger than that in IB--VIIIB groups, and the coordination number of lanthanide elements is most abundant. We also selected NaNO3, Fe（NO3）3·9H2O, Zn（NO3）2·6H2O, Y（NO3）3·3H2O, and La（NO3）3·6H2O as examples to confirm the direct relationship between chemical bonding characteristics and orbital hybrid set by IR spectra. The present study opens the door to reveal the chemical bonding nature of atoms on the basis of hybridization and will provide theoretical guides in structural design at an atomic level.

关键词： hybridization chemical bonding coordination number central cations rare earth

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