Bimetallic nanoparticles serve as a vital class of catalysts with tunable properties suitable for diverse catalytic reactions, yet a comprehensive understanding of their structural evolution under operational conditions as well as their optimal design principles remains elusive. In this study, we unveil a prevalent surface segregation phenomenon in approximately 100 platinum-group-element-based bimetallic nanoparticles through molecular dynamics simulations and derive a thermodynamic descriptor to predict this behavior. Building on the generality and predictability of surface segregation, we propose leveraging this phenomenon to intentionally enrich the nanoparticle surface with noble-metal atoms, thereby significantly reducing their usage while maintaining high catalytic activity and stability. To validate this strategy, we investigate dozens of platinum-based bimetallic nanoparticles for propane dehydrogenation catalysis using first-principles calculations. Through a systematic examination of the catalytic sites on nanoparticle surfaces, we eventually identify several candidates featuring with stable Pt-enriched surface and superior catalytic activity, confirming the feasibility of this approach.
CO Oxidation Catalysed by Pd-based Bimetallic Nanoalloys
基于密度泛函理论的全局几何优化已被用来证明催化团簇的几何结构对Pd基纳米合金上CO氧化反应的能垒的关键影响。我们发现，反应中间体之间的巨大几何变化可能导致非常高的能量势垒，从而对整个过程是禁止的。这对新催化剂的设计和所采用的理论方法都提出了挑战。在理论方面，仔细选择所有反应中间体的几何构型对于充分描述可能的反应路径是至关重要的。从催化剂设计的角度来看，可以通过调节团簇和掺杂剂金属之间的相互作用水平来控制团簇的几何构型，以及通过在单个纳米合金颗粒中混合不同的金属而在吸附物分子和催化剂簇之间进行。我们发现，Pd $_{5}$簇中的Pd原子与单个Ag原子的取代形成Pd $_{4}$ Ag $_{1}$导致簇的CO氧化反应的催化性能的潜在改善。另一方面，一个单一的金原子不提高催化剂的性能，这是由于集群的组成金属和吸附分子之间的较弱的杂化。这种灵活性的性质的x-nanoalloy集群说明微调的可能性，这可能是用于设计新的高效催化材料。
Structures of iron and cobalt bimetallic clusters for optimized chemical vapor deposition growth of single-walled carbon nanotubes
The University of Tokyo（东京大学）；Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS)（基础科学研究院多维碳材料中心）；Dalian University of Technology（大连理工大学）；University of Antwerp（安特卫普大学）
Mechanistic Insights into Active Sites for Electrochemical CO2 and CO Reduction over the Strain-Engineered Dealloyed Cu
Imperial College London（帝国理工学院）；Univ Rouen Normandie, CNRS, INSA Rouen Normandie, Groupe de Physique des Matériaux（鲁昂诺曼底大学，法国国家科学研究中心，鲁昂诺曼底国立应用科学学院，材料物理研究组）；The European Synchrotron - ESRF（欧洲同步辐射装置）；Oxford University（牛津大学）
