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研究生： 劉冠辰
Guan-Chen Liu
論文名稱： The Effect of Au and Rh Nanoclusters on Methanol Decomposition on CuO/Cu(110)
指導教授： 羅夢凡
Meng-Fan Luo
口試委員:
學位類別： 碩士
Master
系所名稱： 理學院 - 物理學系
Department of Physics
論文出版年： 2023
畢業學年度： 111
語文別： 英文
論文頁數： 108
中文關鍵詞： 氧化銅 、銅(110)單晶 、金屬納米糰簇 、甲醇分解
外文關鍵詞： Copper Oxides, Cu(110), Metal Nanoclusters, Methanol Decomposition
相關次數： 點閱：12  下載：0 
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    • 經由蒸鍍生長在氧化銅上的金(Au)和銠(Rh)奈米粒子增加生長在Cu(110)單晶上的氧化銅薄膜對甲醇分解的活性。氧化銅薄膜有(2×1)氧化相和(2×1)和c(6×2)共存相兩種氧化銅相，分別由將Cu(110)曝露於7 – 40 L和1000 L的氧氣生成。氧化銅薄膜的結構由低能電子繞射(LEED)來監控，反應產物則是由熱脫附質譜(TPD)和光電子能譜(PES)來偵測。
    在超高真空環境下，甲醇-d4 (CD3OD)在氧化銅薄膜上分解產生甲醛-d2 (CD2O)、氘分子(D2)和重水(D2O)。金和銠奈米粒子在氧化銅上增加甲醇分解的機率。銠奈米粒子促進一氧化碳的產生。除此之外，甲醛和水的產量隨著金和銠的覆蓋率增加而上升，相反地，氘分子的產量則是下降。氘分子產量下降是由氫原子和羥基(OD-)結合產生水導致。而且，在(2×1)氧化相和(2×1)和c(6×2)共存相兩種氧化銅薄膜上的金和銠奈米粒子對產量的增長百分比不同。
    最小的0.05 ML金和銠奈米粒子或單原子不會增加甲醇在由7 L 和 1000 L曝氧量生成的氧化銅薄膜上的分解。特別是，0.05 ML的Rh小顆奈米粒子或是單原子在(2×1)和c(6×2)共存相的氧化銅上阻擋甲醇的分解。這由產量的降低並且甲醇的吸附量沒有減少來證明。

    The reactivity of copper oxide films grown on Cu(110) single crystal (CuO/Cu(110)) toward methanol decomposition was shown to be enhanced by gold (Au) and Rhodium (Rh) nanoclusters formed by vapor deposition onto the copper oxide films. Two kinds of copper oxide phase were observed on the surface; (2×1) oxide phase and (2×1) and c(6×2) coexistence phase was yielded by exposing Cu(110) to 7 – 40 L and 1000 L of oxygen, respectively. The structures of the copper oxide films were characterized with low electron energy diffraction (LEED), and the reaction products were monitored with temperature programmed desorption (TPD) and synchrotron-based photoelectron spectroscopy (PES).
    Decomposition of methanol-d4 (CD3OD) on CuO/Cu(110) produced formaldehyde-d2 (CD2O), molecular deuterium (D2) and deuterium water (D2O) under UHV conditions. Au and Rh nanoclusters supported on copper oxide films increased the probability of methanol decomposition. Rh nanoclusters facilitate the production of CO. Besides, the production of formaldehyde-d2 and deuterium water was increased with Au and Rh coverage, in contrast, that of deuterium molecules was reduced. The decrease in deuterium production resulted from the combination of deuterium molecules with hydroxyls (OD^-) to produce deuterium water. Moreover, copper oxide films formed with (2×1) oxide phase and (2×1) and c(6×2) coexistence phase showed different increased production after Au and Rh deposition.
    The smallest Au and Rh nanoclusters (0.05 ML) nanoclusters, or single atoms, didn’t enhance methanol decomposition on copper oxide films formed by 7 and 1000 L of oxygen exposure. In particular, 0.05 ML Rh small nanoclusters, or single atoms, supported on copper oxide films with (2×1) and c(6×2) coexistence phase blocked the methanol decomposition. This was evidenced by the lower production and no decrease in the number of monolayer adsorbed methanol.

    Contents 摘要 i Abstract ii 致謝 iii Contents iv List of Figures vi Chapter 1 Introduction 1 Chapter 2 Literature survey 3 2.1 Characterization of copper oxide films grown on Cu(110) 3 2.2 Catalysis enhancement by charge transfer between supported Au single atom and CuO support 6 2.3 The effect of nanocluster size on catalytic performance 9 2.4 Methanol decomposition on oxygen pre-dosed Cu(110) 11 2.5 Methanol decomposition on Rh nanoclusters supported by Al2O3/NiAl(100) 15 2.6 Formate production after methanol decomposition on CuO/Cu(110) 18 Chapter 3 Experimental process and apparatus 22 3.1 Experimental methods 22 3.1.1 Sample cleaning 23 3.1.2 Deposition of Au and Rh nanoclusters 25 3.1.3 Methanol adsorption and reaction 26 3.2 Temperature programmed desorption (TPD) 26 3.2.1 The order of desorption 27 3.2.2 Quadrupole mass spectrometer (QMS) 29 3.2.3 PID temperature controller 31 3.3 Synchrotron-based photoelectron spectroscopy (PES) 32 3.4 Low energy electron diffraction (LEED) 36 Chapter 4 Results and discussion 39 4.1 Growth of copper oxide films on Cu(110) 39 4.2 The effect of oxygen exposure for growing copper oxides on methanol decomposition 41 4.2.1 Methanol decomposition on Cu(110) and a partially oxidized Cu(110) surface 41 4.2.2 Methanol decomposition on a fully oxidized Cu(110) surface 48 4.2.3 Oxygen consumption during methanol decomposition 51 4.3 Methanol decomposition on Au nanoclusters supported on CuO 59 4.4 Methanol decomposition on Rh nanoclusters supported on CuO 69 4.5 0.05 ML Rh small nanoclusters, or single atoms, supported on copper oxide films block methanol decomposition 79 Chapter 5 Conclusion 88 References 89

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