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.

中文翻译：

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过渡金属掺杂铜合金中水蒸气引起的偏析


虽然人们对过渡金属（TM）合金中气体吸附引起的偏析进行了广泛的研究，但对于水蒸气（自然环境中普遍存在的气体）的具体情况尚未得到充分研究。在本文中，我们采用密度泛函理论（DFT）计算结合反应条件下的热力学分析来定量描述Cu主体中掺杂的24种TM杂质的水蒸气诱导偏析现象。我们的结果表明，水分子的吸附显着影响不同铜表面上早期和中期TM杂质的偏聚能。我们进一步阐明了导致强烈水蒸气诱导分离的温度和压力。分离的杂质可以激活表面以进行水离解，这是水煤气变换反应的关键步骤。这一发现提供了反应条件下双金属合金偏析的新知识，有助于我们理解铜合金在材料科学和催化方面的工作机制。