用密度泛函理论研究汞在CeO2(111)表面的吸附

摘要

采用密度泛函理论计算了Hg、HgCl、HgCl2在CeO2 (111)表面的吸附构型、吸附能和态密度.结果表明,Hg在CeO2(111)表面属于弱化学吸附.HgCl与CeO2(111)表面为强化学吸附,是反应的重要中间体.HgCl2在CeO2(111)表面是物理吸附,易发生解离,脱除.氯对于汞的吸附和氧化产生较强的影响,这与实验结果相一致.基于计算结果,得到汞在CeO2 (111)表面的反应机理.%Using density functional theory(DFT),the adsorption configuration,adsorption energies and density of states for Hg,HgC1,HgCl2 on CeO2 (111) surface were calculated.The calculated results show that the adsorption of Hg and HgC1 on CeO2 (111) surface are mainly chemisorption.The adsorption energy of HgCl on CeO2(111) surface is stronger than that of Hg,which indicates that the HgCl-surface is an importantreaction intermediate.HgCl2 adsorption on CeO2(111) surface is physisorption,such that it is easy to remove from the CeO2 (111) surface.The chlorine species has a strong effect on the mercury adsorption and oxidation,which is consistent with the available experimental results.Based on the calculation results,the reaction mechanism of mercury on CeO2 (111) surface is proposed.