The sequence of key elementary steps for ethylene epoxidation on silver was developed from surface science experiments and computational chemistry. This molecular-level mechanistic information was used as an input in computational screening of potential bimetallic alloy catalysts. The aim of the computational screening was to identify a catalyst that would offer higher selectivity to ethylene oxide (EO) than the traditional monometallic silver catalyst. Computational screening led to formulation of a new Cu/Ag alloy that is more selective than Ag to EO. These predictions were verified by steady-state experiments with monolith-supported catalysts. (C) 2004 Elsevier Inc. All rights reserved.