Chemical Insights into High Entropy Alloy Nanoparticle Formation and Reactivity

在化学系大分子、超分子和纳米化学项目的支持下，宾夕法尼亚州立大学的Schaak教授将开发化学反应，形成包含五种或更多元素的高熵合金纳米颗粒。这些纳米颗粒中的大量元素可能导致独特的性质，这些性质在许多应用中都很有用，包括用作与清洁能源技术相关的化学反应的催化剂。Schaak教授和他的团队将开发化学反应，在溶液中制造高熵合金纳米颗粒，并了解它们是如何形成的，为什么形成，以及何时形成。他们还将定义这些纳米颗粒的化学反应能力，以了解它们在接触不同试剂时的变化。从这项研究中获得的知识将通过控制纳米特征以新的方式调整高熵合金的性质，从而在催化和其他领域带来未来的进展。Schaak教授和他的团队将开发基于高熵合金纳米颗粒合成和表征的独特方面的教程和学习模块，这将影响广泛的学生和研究人员社区。Schaak教授还将为职业生涯早期的研究人员发起一项虚拟网络和指导计划。大多数合成高熵合金纳米粒子的策略需要高温加热和快速冷却装载到耐火载体上的金属盐，这提供了纳米级的稳定性。然而，这些方法不允许对纳米颗粒特征进行更精细的控制，这些特征众所周知会影响性能，包括尺寸、均匀性和形状。溶液中发生的化学反应非常适合纳米颗粒的合成，但获得高熵合金的溶液路线仍然有限，对它们如何形成、生长和转化知之甚少。Schaak教授的研究团队将阐明选定的高熵合金纳米颗粒在溶液中形成的途径，并评估不同的反应参数如何影响反应结果。关于高熵合金纳米粒子的化学反应能力的知识也很有限，这对于在应用中使用它们是重要的。高熵合金纳米粒子中大量的组成元素可能导致独特的协同性能，如修饰的选择性和增加催化稳定性。Schaak教授和他的团队将研究高熵合金纳米颗粒的反应性和稳定性，包括在与各种无机试剂的溶液中。这些实验将导致形成新类别的高熵合金纳米颗粒，并提供有关如何控制和调整胶态高熵合金纳米颗粒的应用相关特征的基础知识。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

With the support of the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Professor Schaak of Pennsylvania State University will develop chemical reactions to form nanoparticles of high entropy alloys, which contain five or more elements. The large number of elements in these nanoparticles may lead to unique properties that are useful in many applications, including as catalysts for chemical reactions relevant to clean energy technologies. Prof. Schaak and his group will develop chemical reactions for making high entropy alloy nanoparticles in solution and understand how, why, and when they form. They will also define the chemical reactivity of these nanoparticles to understand how they transform when exposed to different reagents. The knowledge gained from this research will lead to future advances in catalysis and other fields by allowing the properties of high entropy alloys to be tuned in new ways through control over nanoscopic features. Prof. Schaak and his group will develop tutorials and learning modules based on unique aspects of high entropy alloy nanoparticle synthesis and characterization, which will impact a broad community of students and researchers. Prof. Schaak will also launch a virtual networking and mentoring initiative for early-career researchers.Most strategies for synthesizing high entropy alloy nanoparticles require high-temperature heating and rapid cooling of metal salts loaded onto refractory supports, which provide nanoscale stabilization. However, these methods do not allow finer control over nanoparticle features that are well known to influence properties, including size, uniformity, and shape. Chemical reactions that occur in solution are well suited for nanoparticle synthesis, but solution routes to high entropy alloys remain limited, and little is known about how they form, grow, and transform. Prof. Schaak’s research team will elucidate the pathways by which selected high entropy alloy nanoparticles form in solution and evaluate how diverse reaction parameters influence reaction outcomes. There also is limited knowledge about the chemical reactivity of high entropy alloy nanoparticles, which is important for using them in applications. The large number of constituent elements in high entropy alloy nanoparticles is likely to lead to unique synergistic properties, such as modified selectivity and increased stability in catalysis. Prof. Schaak and his group will study the reactivity and stability of high entropy alloy nanoparticles, including in solution with a broad range of inorganic reagents. These experiments will lead to the formation of new classes of high entropy alloy nanoparticles and provide foundational knowledge about how application-relevant features of colloidal high entropy alloy nanoparticles can be controlled and tuned.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.