Theory of surface enrichment in disordered monophasic binary alloys. Numerical computations for Ag-Au alloys

The regular solution model is used to compute the surface enrichment in the (111)- and (100)-faces of silver-gold alloys. Surface enrichment by silver is predicted to increase if the surface plane becomes less saturated and decreases if one raises the temperature. The possible implications of these findings are considered in the light of the recently reported mechanism of the epoxidation of ethylene over silver catalysts