Nanopattering in CeOx/Cu(111): A New Type of Surface Reconstruction and Enhancement of Catalytic Activity.
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-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-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-gas shift process (CO + H2O → H2 + CO2), with the Cu microterraces providing very efficient sites for the dissociation of water and subsequent reaction with CO.
Sanjaya D
SD
Senanayake
Jerzy T
JT
Sadowski
§Facultad de Ciencias, Universidad Central de Venezuela, Caracas, 1020-A Venezuela.
Jaime
J
Evans
Shankhamala
S
Kundu
Stefano
S
Agnoli
Fan
F
Yang
Dario
D
Stacchiola
∥Institute of Solid State Physics, University of Bremen, Bremen, Germany.
Jan I
JI
Flege
Jan
J
Hrbek
Jose A
JA
Rodriguez
catalytic activity; copper surfaces; hydrogen production; surface reconstruction; water−gas shift reaction.