INFEWS N/P/H2O: SusChEM: Collaborative: Controlling Spatial Composition of Nonprecious Metal-based Heteronanostructures for Enhanced Electrocatalytic Performance

该项目涉及与从水和氮气生产氨（NH3）有关的催化电化学过程，以及分解水以产生用于能量储存和燃料及化学品生产的氢气所需的析氧反应（OER）。 这两种工艺都为依赖碳氢化合物资源获得所需氢气的传统工艺提供了替代方案。 因此，该项目将支持NSF在可持续能源生产和食品，能源和水（INFEWS）创新领域的举措，后者通过NH3作为世界氮基肥料生产的主要原材料的重要性。特别是，该研究旨在为目标电化学过程发现有效的非贵金属纳米催化剂，这些过程可以在环境温度条件下运行，而不是基于烃的技术所需的高温条件。 电催化氮还原反应（NRR）具有以比传统的哈伯-博世热催化工艺更低的净能耗产生NH3的潜力，该热催化工艺占世界能耗的1%至2%。 具体而言，该项目寻求NRR和OER催化电解槽的进步。 这项工作将专注于在碱性电化学环境中运行的非贵金属催化剂，从而实现贵金属的低成本，技术支持替代品。该项目建立在初步数据的基础上，这些数据表明，对异质结构纳米颗粒的空间组成和形态的具体控制将能够增强催化活性，并建立对纳米颗粒形式的关键催化剂系统的组成-活性关系的基本理解。具体的研究目标是：（1）合成和表征由具有/不具有合金壳的异质核组成的非贵Fe-Ni双金属的新型异质纳米结构，（2）评价催化剂在碱性体系中用于电化学NRR和OER的反应性和选择性，和（3）开发使用X射线吸收光谱将结构和组成与电催化活性相关联的操作方法。除了目标反应，引入低成本，非贵重的纳米粒子催化剂的广泛的催化应用，包括电催化越来越感兴趣。 验证所提出的新型非贵金属纳米结构，其中特定的空间组成与性能指标和操作表征相关，将使催化剂设计的方法，可以广泛应用于使成本和性能竞争力的催化剂商业化。此外，通过结构设计控制催化剂的选择性将使水处理、能源转换和农业等重要反应取得关键进展。 为了支持这一目标，将建立一个研究和教育的综合方法，以增加学生参与STEM研究，追求STEM专业，并培养下一代领导人在纳米催化剂的跨学科领域。研究人员将积极招募学生，特别是无代表的学生团体，他们的研究计划。研究结果将被整合到教学的本科和研究生课程开发在化学和化学工程部门。此外，调查人员将通过美国化学学会科学教练和阿肯色州工程学院计划的大学，以及为学生和K-12教师组织一个关于纳米催化剂发现的年度研讨会，来加强目前的暑期课程。

The project addresses catalytic electrochemical processes related to the production of ammonia (NH3) from water and nitrogen, and the oxygen evolution reaction (OER) needed to split water to produce hydrogen for energy storage and fuel and chemical production. Both processes offer alternatives to conventional processes that rely on hydrocarbon resources for the needed hydrogen. Thus the project will support NSF's initiatives in the areas of sustainable energy generation and Innovations at the Nexus of Food, Energy, and Water (INFEWS), the latter via the importance of NH3 as the world's primary raw material for nitrogen-based fertilizer production. In particular, the research is aimed at discovering efficient, nonprecious metal nanocatalysts for the targeted electrochemical processes that can operate at ambient temperature conditions rather than the high-temperature conditions required for hydrocarbon-based technologies. The electrocatalytic nitrogen reduction reaction (NRR) has the potential to generate NH3 at lower net energy consumption than the traditional Haber-Bosch thermal catalytic process which accounts for between 1 and 2% of world energy consumption. Specifically, the project seeks advances in catalytic electrolyzers for both NRR and OER. The work will focus exclusively on nonprecious metal bimetallic catalysts operating in alkaline electrochemical environments, thus enabling low-cost, technology-enabling alternatives to the precious metals. The project is built on preliminary data suggesting that specific control of the spatial composition and morphology of heterostructured nanoparticles will enable enhanced catalytic activity and also establish fundamental understanding of composition-activity relationships for key bimetallic systems in nanoparticle form. The specific research objectives are: (1) to synthesize and characterize novel heteronanostructures of nonprecious Fe-Ni bimetals composed of a hetero-core with/without an alloyed shell, (2) to evaluate the reactivity and selectivity of the catalysts for electrochemical NRR and OER in alkaline systems, and (3) to develop in operando methods to correlate the structure and composition with electrocatalytic activity using x-ray absorption spectroscopy. Beyond the targeted reactions, introduction of low-cost, nonprecious nanoparticle catalysts are of increasing interest for a broad range of catalytic applications, including electrocatalysis. Validation of the proposed novel nonprecious nanostructures, where specific spatial composition is correlated with the performance metrics and in operando characterization, will enable an approach to catalyst design that could be widely applied to enable cost- and performance-competitive catalysts for commercialization. Furthermore, controlling catalyst selectivity through structural design would enable key advances for important reactions related to water treatment, energy conversion, and agriculture. To support this objective, an integrated approach of research and education will be established to increase student participation in STEM research, to pursue STEM majors, and to train next-generation leaders in the interdisciplinary field of nanocatalysts. The investigators will actively recruit students, especially unrepresented student groups, to their research programs. The research findings will be integrated into teaching for undergraduate and graduate curriculum development in both Chemistry and Chemical Engineering departments. In addition, the investigators will strengthen the current summer programs by involving K-12 teachers through American Chemical Society Science Coaches and the University of Arkansas Engineering Academy Programs, as well as organizing an annual workshop for students and K-12 teachers on Nanocatalyst Discovery.