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Au/CeO2(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/CeO₂(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/CeO₂(111)的表面吸附行为。在CeO2(111)的平面区域内，经过结构弛豫与优化，确定了五个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Ce4+被还原为Ce3+，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，深入探讨了四种不同台阶结构对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/CeO₂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，为我们深入理解Au/CeO₂(111)的催化机理提供了新的视角。
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关键词:
- Au/CeO2(111) /
- 电荷转移 /
- 吸附能 /
- 第一性原理计算
Au/CeO2(111), as an important catalyst system, has demonstrated excellent catalytic performance in a variety of fields such as the catalytic oxidation and the water-gas shift reactions. In order to deeply reVeal Au/CeO2(111) catalytic mechanism, especially to understand the interaction of the active components on the atomic scale. In this paper, the adsorption properties on the Au/CeO2(111) surface are investigated by calculating the adsorption energy, differential charge density, Bader charge, and the density of states using density functional theory (DFT+U). First, five adsorption sites of Au/CeO2(111) were identified in the planar region of CeO2(111), and the most stable adsorption configuration was found to be located at the bridging position between surface oxygen atoms (the oxygen-oxygen bridging site). It 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 during the adsorption process: the Au atoms are oxidized to Au+, while the Ce4+ ions in the second nearest neighbor of Au are reduced to Ce3+, and the adsorption process is accompanied by a charge transfer phenomenon. Au also exhibits a unique adsorption behavior in the CeO2(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), we find that the higher adsorption energies of Au at the Type II* and Type III sites are mainly attributed 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 transfer from Au to Ce4+ ions, making Type III the preferred adsorption site for Au atoms. By constructing a more comprehensive Au/CeO₂ model, this study breaks through the preVious limitation of focusing only on planar adsorption and reVeals the adsorption mechanism of Au/CeO₂ at the edge of the step, which provides a new perspective for us to deeply understand the catalytic mechanism of Au/CeO₂(111).-
Keywords:
- Au/CeO2(111) /
- Charge transfer /
- Adsorption energy /
- First principles calculations
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[1] Haruta M, Kobayashi T, Sano H, Yamada N 1987Chem. Lett. 16 405
[2] Li Y J, Wen H, Zhang Q, Adachi Y, Arima E, Kinoshita Y, Nomura H, Ma Z, Kou L, Tsukuda Y, Naitoh Y, Sugawara Y, Xu R, Cheng Z 2018Ultramicroscopy 191 51
[3] Zielinski M, Juszczyk W, Kaszkur Z 2022RSC Adv. 12 5312
[4] Berrichi A, Bailiche Z, Bachir R 2022Res. Chem. Intermed. 48 4119
[5] Megías-Sayago C, Lolli A, Ivanova S, Albonetti S, Cavani F, Odriozola J A 2019Catal. Today 333 169
[6] Li Q, Xie W, Chen G, Li Y, Huang Y, Chen X 2015Nano Res. 8 3075
[7] Liu H, Cao Z, Yang S, Ren Q, Dong Z, Liu W, Li Z A, Chen X, Luo L 2024Nano Res. 174986
[8] Kim C, Thompson L 2006J. Catal. 244 248
[9] Chen Y, Hu P, Lee M H, Wang H 2008Surf. Sci. 602 1736
[10] Hernández N C, Grau-Crespo R, De Leeuw N H, Sanz J Fdez 2009Phys. Chem. Chem. Phys. 11 5246
[11] Zhang C, Michaelides A, King D A, Jenkins S J 2010J. Am. Chem. Soc. 132 2175
[12] Engel J, Francis S, Roldan A 2019Phys. Chem. Chem. Phys. 21 19011
[13] Shu P, Tian X, Guo Q, Ren X, Zhao B, Wen H, Tang J, Li Y, Yasuhiro S, Ma Z, Liu J 2024Phys. Scr. 99 105990
[14] Teng B, Wu F, Huang W, Wen X, Zhao L, Luo M 2012ChemPhysChem 13 1261
[15] Lu Y, Quardokus R, Lent C S, Justaud F, Lapinte C, Kandel S A 2010J. Am. Chem. Soc. 132 13519
[16] Lustemberg P G, Pan Y, Shaw B J, Grinter D, Pang C, Thornton G, Pérez R, Ganduglia-Pirovano M V, Nilius N 2016Phys. ReV. Lett. 116 236101
[17] Fu Q, Saltsburg H, Flytzani-Stephanopoulos M 2003Science 301 935
[18] Bezkrovnyi O, Bruix A, Blaumeiser D, Piliai L, Schötz S, Bauer T, Khalakhan I, Skála T, Matvija P, Kraszkiewicz P, Pawlyta M, Vorokhta M, Matolínová I, Libuda J, Neyman K M, Kȩpiński L 2022Chem. Mater. 34 7916
[19] Tibiletti D, Amieiro-Fonseca A, Burch R, Chen Y, Fisher J M, Goguet A, Hardacre C, Hu P, Thompsett D 2005J. Phys. Chem. B 109 22553
[20] Feng J, Guo Q, Shu P L,Wen Y, Wen H F, Ma Z M, Li Y J, Liu J 2023Acta Phys. Sin. 72 110701(in Chinese) [冯婕, 郭强, 舒鹏丽, 温阳, 温焕飞, 马宗敏, 李艳君, 刘俊, 伊戈尔·弗拉基米罗维奇·雅明斯基2023物理学报72 110701]
[21] Perdew J P, Burke K, Ernzerhof M 1996Phys. ReV. Lett. 77 3865
[22] Cococcioni M, De Gironcoli S 2005 Phys. Rev. B 71035105
[23] Zheng Z Y, Wang D, Zhang Y, Yang F, Gong X Q 2020Chin. J. Cata. 41 1360
[24] Wilson E L, Grau-Crespo R, Pang C L, Cabailh G, Chen Q, Purton J A, Catlow C R A, Brown W A, De Leeuw N H, Thornton G 2008J. Phys. Chem. C 112 10918
[25] Ma Z M, Shi Y B, Mu J L, Qu Z, Zhang X M, Li Q, Liu J 2017Appl. Surf. Sci. 394 472
[26] Owen C J, Jenkins S J 2021J. Chem. Phys. 154 164703
[27] Chen L J, Tang Y, Cui L, Ouyang C, Shi S 2013J. of Power Sources 234 69
[28] Kim H Y, Henkelman G 2013J. Phys. Chem. Lett. 4 216
[29] Kozlov S M, Neyman K M 2014Phys. Chem. Chem. Phys. 16 7823
[30] Olbrich R, Pieper H H, Oelke R, Wilkens H, Wollschläger J, Zoellner M H, Schroeder T, Reichling M 2014Appl. Phys. Lett. 104 081910
[31] Barth C, Laffon C, Olbrich R, Ranguis A, Parent Ph, Reichling M 2016Sci Rep. 6 21165
[32] Shu P, Guo Q, Tian X, Wei J, Qu Z, Ren X, Wen H, Tang J, Li Y, Sugawara Y, Ma Z, Liu J 2024Surf. Interfaces 51 104738
[33] Kozlov S M, Viñes F, Nilius N, Shaikhutdinov S, Neyman K M 2012J. Phys. Chem. Lett. 3 1956
[34] Chu D R, Wang Z Q, Gong X Q 2022Surf. Sci 722 122096
[35] Wen H F, Sugawara Y, Li Y J 2020Acta Phys. Sin. 69 210701(in Chinese) [温焕飞, 菅原康弘, 李艳君2020物理学报69 210701]
[36] Zhou H, Wang D, Gong X Q 2020Phys. Chem. Chem. Phys. 22 7738
[37] Zhou C Y, Wang D, Gong X Q 2019Phys. Chem. Chem. Phys. 21 19987
[38] Piliai L, Matvija P, Dinhová T N, Khalakhan I, Skála T, Doležal Z, Bezkrovnyi O, Kepinski L, Vorokhta M, Matolínová I 2022ACS Appl. Mater. Interfaces 14 56280
[39] Janssen E M W, Wiegers G A 1978J. Less-Common Met. 57 P47
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