单原子和双原子合金图谱及设计规则
An Atlas and Design Rules for Single- and Dual-Atom Alloys
中文总结 AI 辅助
本研究通过密度泛函理论构建了铜银表面单双原子合金图谱，发现d电子数接近十时掺杂剂配对最强，并提出反应器锚定概念，为设计目标活性位点合金提供了原则。
中文摘要 AI 辅助
在异相催化、材料科学和凝聚态物理中，一个长期存在的目标是设计具有特定局部原子排列的合金。最近的实验表明，稀有三元合金能够实现双金属合金无法触及的化学性质，但实现这一潜力需要了解在巨大的组成空间中哪些掺杂结构能够形成。通过密度泛函理论筛选，我们构建了一个涵盖铜和银表面过渡金属单原子和双原子合金的图谱，并通过扫描隧道显微镜进行了验证。稳定性遵循电子计数规律：当掺杂剂的组合d电子数接近十时，它们之间的配对最强。宿主金属和表面晶面可用于调控所得活性位点构型，而尺寸失配和自旋解释了围绕这一趋势的偏差。我们进一步引入了反应器锚定概念，其中一种掺杂剂将另一种原本会偏析到体相的掺杂剂锚定在表面。综合来看，这些结果确立了设计具有目标活性位点结构的合金的工程原则。
英文摘要
A long-standing goal across heterogeneous catalysis, materials science, and condensed matter physics is to design alloys with prescribed local atomic arrangements. Recent experiments show that dilute trimetallic alloys unlock chemistries inaccessible to bimetallics, but realizing this potential requires knowing which dopant structures form across an enormous compositional space. Using density functional theory screening, we construct an atlas spanning transition metal single- and dual-atom alloys in Cu and Ag surfaces, which we validate by scanning tunneling microscopy. The stability follows an electron count: dopants pair most strongly when their combined d-electron count approaches ten. Host metal and surface facet can be used to tune the resulting active site motifs, while size mismatch and spin explain variations around this trend. We further introduce a reactor-anchor concept, in which one dopant anchors a second, otherwise bulk-segregating dopant at the surface. Together, these results establish design principles for engineering alloys with targeted active site structures.
