Nanopattering in CeOx/Cu(111): A New Type of Surface Reconstruction and Enhancement of Catalytic Activity

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• 作者：Sanjaya D. Senanayake ; Jerzy T. Sadowski ; Jaime Evans ; Shankhamala Kundu ; Stefano Agnoli ; Fan Yang ; Dario Stacchiola ; Jan I. Flege ; Jan Hrbek ; Jose A. Rodriguez
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2012
• 出版时间：April 5, 2012
• 年：2012
• 卷：3
• 期：7
• 页码：839-843
• 全文大小：322K
• 年卷期：v.3,no.7(April 5, 2012)
• ISSN：1948-7185

文摘

Our results indicate that small amounts of an oxide deposited on a stable metal surface can trigger a massive surface reconstruction under reaction conditions. In low-energy electron microscopy (LEEM) experiments, no reconstruction of Cu(111) is observed after chemisorbing oxygen or after reducing O/Cu(111) in a CO atmosphere. On the other hand, LEEM images taken in situ during the reduction of CeO₂/CuO_1鈥?i>x/Cu(111) show a complex nonuniform transformation of the surface morphology. Ceria particles act as nucleation sites for the growth of copper microterraces once CuO_1鈥?i>x is reduced. Can this reconstructed surface be used to enhance the catalytic activity of inverse oxide/metal catalysts? Indeed, CeO_x on reconstructed Cu(111) is an extremely active catalyst for the water鈥揼as shift process (CO + H₂O 鈫?H₂ + CO₂), with the Cu microterraces providing very efficient sites for the dissociation of water and subsequent reaction with CO.

Keywords:

surface reconstruction; catalytic activity; hydrogen production; water鈭抔as shift reaction.; copper surfaces