Alloy catalyst in a reactive environment: the example of ag-cu particles for ethylene epoxidation.
Combining first-principles calculations and in situ photoelectron spectroscopy, we show how the composition and structure of the surface of an alloy catalyst is affected by the temperature and pressure of the reagents. The Ag-Cu alloy, recently proposed as an improved catalyst for ethylene epoxidation, forms a thin Cu-O surface oxide, while a Ag-Cu surface alloy is found not to be stable. Several possible surface structures are identified, among which the catalyst surface is likely to dynamically evolve under reaction conditions.
Piccinin
Simone
S
School of Physics, The University of Sydney, Sydney, New South Wales 2006, Australia.
Zafeiratos
Spiros
S
Stampfl
Catherine
C
Hansen
Thomas W
TW
Hävecker
Michael
M
Teschner
Detre
D
Bukhtiyarov
Valerii I
VI
Girgsdies
Frank
F
Knop-Gericke
Axel
A
Schlögl
Robert
R
Scheffler
Matthias
M