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/CuO1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 CuO1鈥?i>x is reduced. Can this reconstructed surface be used to enhance the catalytic activity of inverse oxide/metal catalysts? Indeed, CeOx 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