Au/CeO_(2)(111)表面吸附的电荷转移特性  

Charge transfer characteristics of Au adsorption on CeO_(2)(111)surface

作　　者：田馨 舒鹏丽 张珂童 曾德超 姚志飞 赵波慧 任晓森 秦丽[1,2,4] 朱强 魏久焱[1,5] 温焕飞 李艳君[1,5] 菅原康弘 唐军[1,3,4] 马宗敏 刘俊[1,2,4] TIAN Xin;SHU Pengli;ZHANG Ketong;ZENG Dechao;YAO Zhifei;ZHAO Bohui;REN Xiaosen;QIN Li;ZHU Qiang;WEI Jiuyan;WEN Huanfei;LI Yanjun;Yasuhiro Sugawara;TANG Jun;MA Zongmin;LIU Jun(State Key Laboratory of Dynamic Testing Technology,North University of China,Taiyuan 030051,China;School of Instrument and Electronics,North University of China,Taiyuan 030051,China;School of Semiconductor and Physics,North University of China,Taiyuan 030051,China;Shanxi Key Laboratory of Quantum Sensing and Precision Measurement,North University of China,Taiyuan 030051,China;Department of Applied Physics,Graduate School of Engineering,Osaka University,Osaka 5650871,Japan)

机构地区：[1]中北大学,省部共建动态测试技术国家重点实验室,太原030051 [2]中北大学仪器与电子学院,太原030051 [3]中北大学半导体与物理学院,太原030051 [4]中北大学,量子传感与精密测量山西省重点实验室,太原030051 [5]日本大阪大学,工学研究科精密科学应用物理学,日本大阪5650871

出　　处：《物理学报》2025年第5期39-50,共12页Acta Physica Sinica

基　　金：国家重点研发计划(批准号:2022YFC2204104);国家自然科学基金国际合作与交流项目(批准号:62220106012);山西省杰出青年基金(批准号:202103021221007);山西量子传感与精密测量国际联合实验室(批准号:202204041101015);山西省基础研究计划(批准号:202203021212502)资助的课题.

摘　　要：Au/CeO_(2)(111)作为一种重要的催化剂体系,在催化氧化、水气转换反应等多个领域展现出优异的催化性能.为了深入揭示其催化机理,特别是在原子尺度上理解活性组分的相互作用.本文采用密度泛函理论(DFT+U)计算方法,构建了Au/CeO_(2)(111)体系的原子尺度模型,通过计算该模型的吸附能、差分电荷密度、巴德电荷以及态密度,揭示了Au/CeO_(2)(111)的表面吸附行为.在CeO_(2)(111)的平面区域内,经过结构弛豫与优化,确定了5个Au吸附位点.其中最为稳定的吸附位点并非传统上认为的氧顶位,而是氧-氧桥位.在这种吸附构型下,电荷从Au向Ce4+转移,导致Ce^(4+)被还原为Ce^(3+),伴随着显著的电荷转移现象.过去的研究更多地关注了平面区域的吸附行为,而忽视了台阶边缘区域在催化过程中的重要性.因此,本研究进一步扩展了研究范围,深入探讨了4种不同台阶结构对Au吸附的影响,其中,Type II*和Type III台阶因高度欠配位的Ce原子增强了对Au原子的吸附,特别是Type III台阶通过显著的电荷转移成为Au的首选吸附位点.本研究通过构建更全面的Au/CeO_(2)模型,突破了以往仅关注平面吸附的局限性,揭示了Au/CeO2在台阶边缘的吸附机制,为深入理解Au/CeO_(2)(111)的催化机理提供了新的视角.Au/CeO_(2)(111),as an important catalyst system,has demonstrated excellent catalytic performances in a variety of fields such as the catalytic oxidation and the water-gas shift reactions.In order to reveal in depth the Au/CeO_(2)(111)catalytic mechanism,especially to understand the interaction of the active components on an atomic scale,in this work,the adsorption properties on the Au/CeO_(2)(111)surface are investigated by calculating the adsorption energy,differential charge density,Bader charge,and the density of states by using density functional theory(DFT+U).First,five adsorption sites of Au/CeO_(2)(111)are identified in the planar region of CeO_(2)(111),and the most stable adsorption configuration is found to be located at the bridging position between surface oxygen atoms(the oxygen-oxygen bridging site),which suggests that Au interacts more closely with the oxygen-oxygen bridging sites.Further,the differential charge density and Bader charge reveal the charge transfer mechanism in the adsorption process.Specifically,the Au atoms are oxidized into Au^(+),while the Ce^(4+) ions in the second nearest neighbor of Au are reduced to Ce^(3+),and the adsorption process is accompanied by a charge transfer phenomenon.Au also exhibits a unique adsorption behavior in the CeO_(2)(111)step-edge region,where a highly under-allocated environment is formed due to the decrease in the coordination number of atoms in the step edge,which enhances the adsorption of Au in a highly under-allocated environment.The adsorption of Au at the step edge is enhanced by the lower coordinated environment due to the reduced coordination number of the atoms at the step edge.By comparing four different types of step structures(Type I,Type II,Type II*,and Type III),it is found that the higher adsorption energy of Au at Type II*site and that at Type III site are both mainly due to the lower coordinated state of Ce atoms at these sites.Charge transfer is also particularly pronounced at the Type III sites.It is also accompanied by electron tran

关 键 词：Au/CeO_(2)(111) 电荷转移 吸附能 第一性原理计算 

分 类 号：O643.36[理学—物理化学] O647.3[理学—化学] O469