Bonding Structure, Dehydrogenation, and Dimerization of 1,3-C6H4 from Decomposition of 1,3-C6H4I2 on Cu(100)

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• 作者：Yung-Hsuan Liao ; Yi-Shiue Lin ; Tz-Shiuan Wu ; Shu-Kuan Lin ; Jong-Liang Lin ; Liang-Jen Fan ; Yaw-Wen Yang ; Jiing-Chyuan Lin
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：December 1, 2011
• 年：2011
• 卷：115
• 期：47
• 页码：23428-23434
• 全文大小：1002K
• 年卷期：v.115,no.47(December 1, 2011)
• ISSN：1932-7455

文摘

Temperature-programmed reaction/desorption, Auger electron spectroscopy, X-ray photoelectron spectroscopy, and near-edge X-ray absorption fine structure in combination of calculations based on density functional theory have been employed to investigate adsorption and reaction of 1,3-C₆H₄I₂ on Cu(100). At 100 K, the surface species after 1,3-C₆H₄I₂ adsorption are found to be 1,3-C₆H₄I₂, C₆H₄I, and 1,3-C₆H₄. The formation of these adsorbates is dependent on the adsorption sites of 1,3-C₆H₄I₂. 1,3-C₆H₄I₂ adsorbed with the ring at a hollow site and parallel to the surface is predicted to be unstable and preferentially leads to C鈥揑 bond dissociation. 1,3-C₆H₄, the intermediate from 1,3-C₆H₄I₂ decomposition, has a tilted adsorption geometry with a distorted ring. H₂ is the only reaction product observed after 550 K in the 1,3-C₆H₄I₂ decomposition on Cu(100), with all of the carbon atoms left on the surface. Dimerization of 1,3-C₆H₄ molecules on Cu(100) has been described computationally, showing an activated and exothermic process. With the theoretically obtained activation energy of 28.2 kcal/mol and estimated surface coverages, coupling of 1,3-C₆H₄ can occur by second-order kinetics before H₂ evolution. Dimerization of 1,3-C₆H₄ on Cu(100) shows a different intermolecular interaction behavior from those of 1,2-C₆H₄ and 1,4-C₆H₄ on copper single crystal surfaces.