ERI: Better by Design: Rational Design and Synthesis of Alloy (Electro)Catalysts Atom-by-Atom

ERI：更好的设计：逐原子合金（电）催化剂的合理设计与合成

• 批准号: 2301427
• 负责人: Ian McCrum
• 金额: $ 19.99万
• 依托单位: Clarkson University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2301427&HistoricalAwards=false
• 关键词: ERI; Better; Design; Rational; Synthesis

Catalysis has long been a key technology for facilitating the efficient manufacture of fuels and chemicals from fossil resources, while also relying on thermal process energy derived from fossil-fuel combustion. The recent transition to “clean” energy technology has stimulated research in alternative energy sources and associated research and development of electrocatalytic processes for both chemical manufacturing and reduction of greenhouse gas emissions. To those ends, the project explores the design of bimetallic alloy electrocatalysts for two critical nitrogen reactions – ammonia synthesis and nitric acid reduction. In particular, this Engineering Research Initiation (ERI) project provides an opportunity for the early-career researcher to further investigate a novel alloy catalyst design approach – selective step decoration – advanced by his research group. Such improved catalysts will expand the scale and scope with which electrocatalysis can replace traditional processes, while also supporting related educational and outreach activities focused on K-12 students. Selective step decoration involves the electrochemical deposition of one type of metal atom selectively onto step-edges on the surface of another metal. This yields a surface which exposes bimetallic surface sites, as on a bulk bimetallic alloy, but with a known structure and composition, and on top of a pure metal substrate. The goal of this ERI project is to expand the selective step decoration technique into a novel method capable of synthesizing a wide variety of multi-metallic surface alloy catalysts, and to use these catalysts, with their well-defined and simpler structure, as a model testbed to understand how alloy composition dictates catalyst stability, activity, and selectivity. Achieving the promise of selective step decorated bimetallic alloy electrocatalysts requires that two needs be addressed: (1) synthesis techniques must be developed that can directly control both alloy composition and structure at the catalyst surface, and (2) simple design rules must be created that relate performance of the alloy catalyst to its structure and composition. To overcome these limitations, two primary objectives will be pursued using a combination of density functional theory (DFT) computational modeling and experiments on single-crystal electrodes having a well-defined surface structure. Those objectives are: (1) identify the driving forces for ad-atom deposition, dissolution (corrosion), and segregation as a function of ad-atom/substrate pair across a variety of substrates to understand alloy stability in operando, and (2) identify simple descriptors (properties of the pure components) and the general rules which govern alloy catalytic activity and selectivity as a function of ad-atom/substrate pairs. Determining the conditions for a particular ad-atom's favorable deposition on, dissolution from, or segregation with a particular substrate will identify specific pairs of ad-atoms/substrates for which selective step decoration is possible. Additionally, the study will reveal insights into how the stability of an alloy differs from that of its pure components. With DFT, the driving forces for deposition, dissolution, and segregation will be quantified, to enable the prediction of surface alloy stability in the electrochemical environment for any pair of metals. By using the same well-defined, step-decorated surface alloys to measure the activity and selectivity of a particular set of reactions (nitrogen and nitric oxide reduction) in combination with DFT modeling, the properties of each alloy component (e.g., d-band center, work function, and the hotly debated potential of zero charge) that dictate alloy catalyst performance will be determined. Whether the governing rules that limit pure single metal catalysts, such as adsorbate scaling relations, hold true for alloys will also be determined.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.

长期以来，催化一直是促进利用化石资源高效生产燃料和化学品的关键技术，同时也依赖化石燃料燃烧产生的热加工能源，最近向“清洁”能源技术的转变刺激了替代能源的研究。以及用于化学制造和减少温室气体排放的电催化工艺的相关研究和开发为此，该项目探索了用于两个关键氮反应（特别是氨合成和硝酸还原）的双金属合金电催化剂的设计。该工程研究启动（ERI）项目为早期职业研究人员提供了进一步研究其研究小组提出的新型合金催化剂设计方法（选择性步骤装饰）的机会，这种改进的催化剂将扩大电催化的规模和范围。取代传统工艺，同时还支持针对 K-12 学生的相关教育和推广活动。选择性台阶装饰涉及将一种金属原子选择性地电化学沉积到另一种金属表面的台阶边缘上，从而产生暴露的表面。双金属表面位点，如块状双金属合金，但具有已知的结构和成分，并且位于纯金属基底之上，该 ERI 项目的目标是将选择性步骤技术装饰扩展到能够合成双金属的新方法。各种各样的多金属表面合金催化剂，并使用这些具有明确和简单结构的催化剂作为模型测试平台，以了解合金成分如何决定催化剂的稳定性、活性和选择性，从而实现选择性步骤的承诺。装饰双金属合金电催化剂需要满足两个需求：（1）必须开发能够直接控制催化剂表面合金成分和结构的合成技术，（2）必须创建与合金催化剂性能相关的简单设计规则为了克服这些限制，将使用密度泛函理论（DFT）计算模型和具有明确表面结构的单晶电极的实验相结合来实现两个主要目标：（1）识别驱动力。 ad 原子沉积、溶解（腐蚀）和偏析作为 ad 原子/基底对在各种基底上的函数，以了解操作中的合金稳定性，以及（2）识别简单的描述符（纯组分的属性）和控制合金催化活性和选择性作为ad原子/底物对的函数的一般规则，确定特定ad原子在特定底物上有利沉积、溶解或分离的条件。此外，该研究还将通过 DFT 揭示合金的稳定性与其纯组分的稳定性有何不同，即沉积、溶解的驱动力。和偏析将被量化，通过使用相同的明确的、阶梯修饰的表面合金来测量一组特定反应的活性和选择性，从而能够预测任何金属对的电化学环境中的表面合金稳定性。 （氮和一氧化氮还原）与 DFT 建模相结合，决定合金催化剂性能的每种合金成分的性质（例如 d 带中心、功函数和备受争议的零电荷电势）是否将被确定。限制纯单金属催化剂的限制，例如吸附物结垢关系，也适用于合金。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优点和更广泛的影响审查标准进行评估，被认为值得支持。