Periodic density functional theory calculations have been performed to investigate the chemisorption behavior of COz molecule on a series of surface alloys that are built by dispersing individual middle-late transitio...Periodic density functional theory calculations have been performed to investigate the chemisorption behavior of COz molecule on a series of surface alloys that are built by dispersing individual middle-late transition metal （TM） atoms （TM = Fe, Co, Ni, Ru, Rh, Pd, Ag, Os, lr, Pt, Au） on the Cu（100） and Cu（lll） surfaces. The most stable configurations of CO2 chemisorbed on different TM/Cu surfaces are determined, and the results show that among the late transition metals, Co, Ru, and Os are potentially good dopants to enhance the chemisorption and activation of CO2 on copper surfaces. To obtain a deep understanding of the adsorption property, the bonding characteristics of the adsorption bonds are carefully examined by the crystal orbital Hamilton population technique, which reveals that the TM atom primarily provides d orbitals with z-component, namely dz2, dxz, and dvz orbitals to interact with the adsorbate.展开更多
The adsorption of cyanide on the top site of a series of transition metal M（100） （M = Cu, Ag, Au, Ni, Pd, Pt） surfaces via carbon and nitrogen atoms respectively, with the CN axis perpendicular to the surface, has...The adsorption of cyanide on the top site of a series of transition metal M（100） （M = Cu, Ag, Au, Ni, Pd, Pt） surfaces via carbon and nitrogen atoms respectively, with the CN axis perpendicular to the surface, has been studied by means of density functional theory and cluster model. Geometry, adsorption energy and vibrational frequencies have been determined, and the present calculations show that the adsorption of CN through C-end on metal surface is more favorable than that via N-end for the same surface. The vibrational frequencies of CN for C-down configuration on surface are blue-shifted with respect to the free CN, which is contrary to the change of vibrational frequencies when CN is adsorbed by N-down structure. Furthermore, the charge transfer from surface to CN causes the increase of surface work function.展开更多
Molecular structures of adsorbed waters at metal surfaces are essential to understanding the widespread processes ranging from ice nucleation,to water involved catalytic surface reactions,to many phenomena of biologic...Molecular structures of adsorbed waters at metal surfaces are essential to understanding the widespread processes ranging from ice nucleation,to water involved catalytic surface reactions,to many phenomena of biological and astrochemical importance.Instead of providing a comprehensive literature survey,we focus in this review on detailed structural information,such as water orientations and occupation sites,of intact waters at low temperatures and ultrahigh vacuum conditions investigated by various surface techniques.Despite progresses made in direct imaging the surface waters at high resolutions,as exemplified in a close-packed（e.g.Pd（111）） and an open metal surfaces（e.g.Cu（110）） supported waters,structural mysteries remain at diverse metal surfaces.We highlight experimental challenges and discuss structural mysteries in elucidating surface water structures at molecular levels.展开更多
Periodic density functional theory calculations have been carried out to investigate the effect of TM atom supported on different Cu surfaces towards the activation for CO2 molecules. The most stable configuration of ...Periodic density functional theory calculations have been carried out to investigate the effect of TM atom supported on different Cu surfaces towards the activation for CO2 molecules. The most stable configuration of CO2 on various TM/Cu（TM = Fe, Co, Ni, Cu） surfaces is determined and the results show that the cobalt is potentially excellent admetal to enhance the chemisorption of CO2 on copper surfaces among the late 3 d-metals. To deep understand the adsorption property, the bond characteristics of the adsorption bonds are carefully examined by the crystal orbital Hamilton population technique and charge density difference analysis. The result reveals that the interaction between the CO2 molecule and TM/Cu surface primarily derive from the TM–C bond. Moreover, the defined adsorption bond strength（I） between CO2 and substrate could be a descriptor for TM-supported surface.展开更多
Accurate description of the adsorption process of reactants on metal surfaces from theory is crucial for mechanistic understanding of activity and selectivity of metal catalysts, but it remains challengeable for the n...Accurate description of the adsorption process of reactants on metal surfaces from theory is crucial for mechanistic understanding of activity and selectivity of metal catalysts, but it remains challengeable for the nowadays first-principles theory due to the lack of proper exchange-correlation functional describing the distinct interactions involved. We studied here the potential energy surfaces of ethylene adsorption on Ag(111), Rh(111) and Ir(111) using density functional theory calculations and (meta)-GGA functional including PBE, BEEF-vdW, SCAN, and SCAN+rVV10. For ethylene adsorption on noble metal Ag(111), it is found that BEEF-vdW, SCAN and SCAN+rVV10 predict the presence of the physisorption states only. For Rh(111), both SCAN and SCAN+rVV10 find that there is a precursor physisorption state before the chemisorption state. In contrast, there is no precursor state found based on potential energy surfaces from BEEF-vdW and PBE. Whereas for Ir(111), BEEF-vdW predicts the existence of a rather shallow precursor physisorption state, in addition to the chemisorption state. Irrespective to the transition metals considered, we find that SCAN+rVV10 gives the strongest binding strength, followed by SCAN, and PBE/BEEF-vdW, accordingly. The present work highlights great dependence of potential energy surface of ethylene adsorption on transition metal surfaces and exchange-correlation functionals.展开更多
基金supported by the National Natural Science Foundation of China(21373048,21203027,and 21371034)
文摘Periodic density functional theory calculations have been performed to investigate the chemisorption behavior of COz molecule on a series of surface alloys that are built by dispersing individual middle-late transition metal （TM） atoms （TM = Fe, Co, Ni, Ru, Rh, Pd, Ag, Os, lr, Pt, Au） on the Cu（100） and Cu（lll） surfaces. The most stable configurations of CO2 chemisorbed on different TM/Cu surfaces are determined, and the results show that among the late transition metals, Co, Ru, and Os are potentially good dopants to enhance the chemisorption and activation of CO2 on copper surfaces. To obtain a deep understanding of the adsorption property, the bonding characteristics of the adsorption bonds are carefully examined by the crystal orbital Hamilton population technique, which reveals that the TM atom primarily provides d orbitals with z-component, namely dz2, dxz, and dvz orbitals to interact with the adsorbate.
基金the National Natural Science Foundation of China (20673019, 20773024)the Natural Science Foundation of Fujian Province (U0650012)the New Century Excellent Talents in University and the Initial Funding for Talents of Fuzhou University (2008-XQ-07, XRC-0732)
文摘The adsorption of cyanide on the top site of a series of transition metal M（100） （M = Cu, Ag, Au, Ni, Pd, Pt） surfaces via carbon and nitrogen atoms respectively, with the CN axis perpendicular to the surface, has been studied by means of density functional theory and cluster model. Geometry, adsorption energy and vibrational frequencies have been determined, and the present calculations show that the adsorption of CN through C-end on metal surface is more favorable than that via N-end for the same surface. The vibrational frequencies of CN for C-down configuration on surface are blue-shifted with respect to the free CN, which is contrary to the change of vibrational frequencies when CN is adsorbed by N-down structure. Furthermore, the charge transfer from surface to CN causes the increase of surface work function.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No.YYYJ-0912)
文摘Molecular structures of adsorbed waters at metal surfaces are essential to understanding the widespread processes ranging from ice nucleation,to water involved catalytic surface reactions,to many phenomena of biological and astrochemical importance.Instead of providing a comprehensive literature survey,we focus in this review on detailed structural information,such as water orientations and occupation sites,of intact waters at low temperatures and ultrahigh vacuum conditions investigated by various surface techniques.Despite progresses made in direct imaging the surface waters at high resolutions,as exemplified in a close-packed（e.g.Pd（111）） and an open metal surfaces（e.g.Cu（110）） supported waters,structural mysteries remain at diverse metal surfaces.We highlight experimental challenges and discuss structural mysteries in elucidating surface water structures at molecular levels.
基金supported by the National Natural Science Foundation of China(21773030,21203027 and 21371034)
文摘Periodic density functional theory calculations have been carried out to investigate the effect of TM atom supported on different Cu surfaces towards the activation for CO2 molecules. The most stable configuration of CO2 on various TM/Cu（TM = Fe, Co, Ni, Cu） surfaces is determined and the results show that the cobalt is potentially excellent admetal to enhance the chemisorption of CO2 on copper surfaces among the late 3 d-metals. To deep understand the adsorption property, the bond characteristics of the adsorption bonds are carefully examined by the crystal orbital Hamilton population technique and charge density difference analysis. The result reveals that the interaction between the CO2 molecule and TM/Cu surface primarily derive from the TM–C bond. Moreover, the defined adsorption bond strength（I） between CO2 and substrate could be a descriptor for TM-supported surface.
基金supported by the National Key R&D Program of China (No.2017YFB0602205 and No.2018YFA0208603)the National Natural Science Foundation of China (No.91645202)the Chinese Academy of Sciences (No.QYZDJ-SSW-SLH054)
文摘Accurate description of the adsorption process of reactants on metal surfaces from theory is crucial for mechanistic understanding of activity and selectivity of metal catalysts, but it remains challengeable for the nowadays first-principles theory due to the lack of proper exchange-correlation functional describing the distinct interactions involved. We studied here the potential energy surfaces of ethylene adsorption on Ag(111), Rh(111) and Ir(111) using density functional theory calculations and (meta)-GGA functional including PBE, BEEF-vdW, SCAN, and SCAN+rVV10. For ethylene adsorption on noble metal Ag(111), it is found that BEEF-vdW, SCAN and SCAN+rVV10 predict the presence of the physisorption states only. For Rh(111), both SCAN and SCAN+rVV10 find that there is a precursor physisorption state before the chemisorption state. In contrast, there is no precursor state found based on potential energy surfaces from BEEF-vdW and PBE. Whereas for Ir(111), BEEF-vdW predicts the existence of a rather shallow precursor physisorption state, in addition to the chemisorption state. Irrespective to the transition metals considered, we find that SCAN+rVV10 gives the strongest binding strength, followed by SCAN, and PBE/BEEF-vdW, accordingly. The present work highlights great dependence of potential energy surface of ethylene adsorption on transition metal surfaces and exchange-correlation functionals.
