In order to understand the long-standing problem of the nature of glass states, we perform intensive simulations on the thermodynamic properties and potential energy surface of an ideal glass. It is found that the ato...In order to understand the long-standing problem of the nature of glass states, we perform intensive simulations on the thermodynamic properties and potential energy surface of an ideal glass. It is found that the atoms of an ideal glass manifest cooperative diffusion, and show clearly different behavior from the liquid state. By determining the potential energy surface, we demonstrate that the glass state has a fiat potential landscape, which is the critical intrinsic feature of ideal glasses. When this potential region is accessible through any thermal or kinetic process, the glass state can be formed and a glass transition will occur, regardless of any special structural character. With this picture, the glass transition can be interpreted by the emergence of conlgurational entropies, as a consequence of flat potential landscapes.展开更多
Science generally proceeds based on a mutual interaction between theory and experiment： theory can explain experimental phenomena and propose general rules for the design of new experiments while experiment can verif...Science generally proceeds based on a mutual interaction between theory and experiment： theory can explain experimental phenomena and propose general rules for the design of new experiments while experiment can verify theoretical predictions and discover new phenomena to improve theories. Yet, the progress of heterogeneous catalysis mainly relied on experimental advances for a long time. In its early days, heterogeneous catalysis was an empirically applied field,展开更多
The efficient fixation and utilization of CO_(2) has been consistently pursued by chemists for decades.Although Cu-based catalysts,e.g.,Cu/ZnO/Al_(2)O_(3),have been widely used in industry for methanol synthesis from ...The efficient fixation and utilization of CO_(2) has been consistently pursued by chemists for decades.Although Cu-based catalysts,e.g.,Cu/ZnO/Al_(2)O_(3),have been widely used in industry for methanol synthesis from CO_(2) hydrogenation(CO_(2)+3H_(2)→H_(3)COH+H_(2)O),many issues on the mechanism and the kinetics remain largely uncertain.For example,the surface site for CO_(2) activation and the synergetic effect between Cu and oxide have been hotly debated in literature.In the past few years,theoretical modeling on pure Cu surfaces and Cu/oxide interfaces has been utilized to provide insight into these important questions.Here we will review the recent theoretical advances on simulating this complex heterogeneous catalytic process with first principles density functional theory(DFT)calculations and kinetics modeling.The theoretical results on the mechanism and the kinetics are compared and summarized.展开更多
基金Supported by the National Natural Science Foundation of Chinathe National Basic Research Program of China
文摘In order to understand the long-standing problem of the nature of glass states, we perform intensive simulations on the thermodynamic properties and potential energy surface of an ideal glass. It is found that the atoms of an ideal glass manifest cooperative diffusion, and show clearly different behavior from the liquid state. By determining the potential energy surface, we demonstrate that the glass state has a fiat potential landscape, which is the critical intrinsic feature of ideal glasses. When this potential region is accessible through any thermal or kinetic process, the glass state can be formed and a glass transition will occur, regardless of any special structural character. With this picture, the glass transition can be interpreted by the emergence of conlgurational entropies, as a consequence of flat potential landscapes.
文摘Science generally proceeds based on a mutual interaction between theory and experiment： theory can explain experimental phenomena and propose general rules for the design of new experiments while experiment can verify theoretical predictions and discover new phenomena to improve theories. Yet, the progress of heterogeneous catalysis mainly relied on experimental advances for a long time. In its early days, heterogeneous catalysis was an empirically applied field,
基金This work was supported by the National Natural Science Foundation of China(No.20825311)973 program(No.2011CB808500)+1 种基金Science and Technology Commission of Shanghai Municipality(No.08DZ2270500)Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institute of Higher Learning.
文摘The efficient fixation and utilization of CO_(2) has been consistently pursued by chemists for decades.Although Cu-based catalysts,e.g.,Cu/ZnO/Al_(2)O_(3),have been widely used in industry for methanol synthesis from CO_(2) hydrogenation(CO_(2)+3H_(2)→H_(3)COH+H_(2)O),many issues on the mechanism and the kinetics remain largely uncertain.For example,the surface site for CO_(2) activation and the synergetic effect between Cu and oxide have been hotly debated in literature.In the past few years,theoretical modeling on pure Cu surfaces and Cu/oxide interfaces has been utilized to provide insight into these important questions.Here we will review the recent theoretical advances on simulating this complex heterogeneous catalytic process with first principles density functional theory(DFT)calculations and kinetics modeling.The theoretical results on the mechanism and the kinetics are compared and summarized.
