Activated dissociation of H_(2) on the Cu(001)surface:The role of quantum tunneling  

作　　者：于小凡 童洋武 杨勇 Xiaofan Yu;Yangwu Tong;Yong Yang(Key Laboratory of Photovoltaic and Energy Conservation Materials,Institute of Solid State Physics,HFIPS,Chinese Academy of Sciences,Hefei 230031,China;Science Island Branch of Graduate School,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]Key Laboratory of Photovoltaic and Energy Conservation Materials,Institute of Solid State Physics,HFIPS,Chinese Academy of Sciences,Hefei 230031,China [2]Science Island Branch of Graduate School,University of Science and Technology of China,Hefei 230026,China

出　　处：《Chinese Physics B》2023年第10期151-162,共12页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.11474285 and 12074382)。

摘　　要：The activation and dissociation of hydrogen molecules(H_(2))on the Cu(001)surface are studied theoretically.Using first-principles calculations,the activation barrier for the dissociation of H_(2) on Cu(001)is determined to be~0.59 eV in height.It is found that the electron transfer from the copper substrate to H_(2) plays a key role in the activation and breaking of the H–H bond,and the formation of the Cu–H bonds.Two stationary states are identified at around the critical height of bond breaking,corresponding to the molecular and the dissociative states,respectively.Using the transfer matrix method,we also investigate the role of quantum tunneling in the dissociation process along the minimum energy pathway(MEP),which is found to be significant at or below room temperature.At a given temperature,the tunneling contributions due to the translational and the vibrational motions of H_(2) are quantified for the dissociation process.Within a wide range of temperature,the effects of quantum tunneling on the effective barriers of dissociation and the rate constants are observed.The deduced energetic parameters associated with the thermal equilibrium and non-equilibrium(molecular beam)conditions are comparable to experimental data.In the low-temperature region,the crossover from classical to quantum regime is identified.

关 键 词：H_(2) CU(001) DISSOCIATION quantum tunneling density functional theory(DFT) transfer matrix method 

分 类 号：O413[理学—理论物理]