Water-Vapor-Induced Segregation in Transition Metal-Doped Copper Alloys

While extensive research has been conducted on gas adsorption-induced segregation in transition metal (TM) alloys, the specific case of water vapor, one ubiquitous gas in natural environments, has not been well studied. In this paper, we employ density functional theory (DFT) calculations coupled with thermodynamic analysis under reaction conditions to quantitatively describe the phenomenon of water-vapor-induced segregation in 24 TM impurities doped in the Cu host. Our results reveal that the adsorption of water molecules significantly influences the segregation energies of early and middle TM impurities in different Cu surfaces. We further elucidate the temperatures and pressures that lead to strong water-vapor-induced segregation. The segregated impurities could activate the surface for water dissociation, a critical step in the water–gas shift reaction. This finding provides new knowledge of bimetallic alloy segregation under reaction conditions and helps us understand the working mechanism of Cu alloys in material science and catalysis.