NSF-DFG Echem: Operando Electronic Structure Determination of Iron and its Time-Dependent Dynamics in FexNi100-x(OH)y Electrooxidation Catalysts

NSF-DFG Echem：FexNi100-x(OH)y 电氧化催化剂中铁的操作电子结构测定及其随时间变化的动力学

• 批准号: 2055245
• 负责人: Lauren Greenlee
• 金额: $ 38万
• 依托单位: University of Arkansas
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-15 至 2021-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2055245&HistoricalAwards=false
• 关键词: NSF; DFG; Echem; Operando; Electronic

This project aims to identify the structure of iron within iron-nickel hydroxide catalyst materials. These materials are highly active electrocatalysts for key reactions important to next-generation energy conversion and storage, including water electrolysis to produce hydrogen and battery electrodes. Understanding the chemistry of the iron species underpins the overall goal of designing and synthesizing non-precious metal electrocatalysts to support our future energy economy. These electrocatalyst materials will also likely play a role in other future electrochemical technologies, including chemical conversion and upcycling, biomass conversion, water treatment, and resource recovery. As such, this project, and its pursuit of understanding how iron structure changes in the electrochemical environment, is critical to support national energy security, as well as to advance society toward clean energy technologies. Discoveries made will support a wide range of research activities focused on similar non-precious metal oxides and hydroxides, advancing not only the science of iron-nickel hydroxides but of other similar materials and of synchrotron-based spectroscopy techniques aimed at probing catalyst materials in their operating environments. This U.S.-German collaboration will also strengthen international scientific relationships and contribute to the development of a diverse, globally competitive science and engineering workforce.The overarching research goal of this proposal is to experimentally probe Fe electronic structure under alkaline electrooxidation conditions by combining materials expertise with the x-ray spectroscopy instrumentation and expertise. Collaboratively conducted operando experiments will allow the team to unequivocally describe electronic state(s) of Fe and to understand the time dependency and hysteresis of Fe structural changes in FexNi100-x(OH)y nanocatalysts. The electrocatalytic reaction of focus will be the alkaline oxygen evolution reaction (OER). This project will further scientific understanding of the chemical and electronic structure of the active site for the OER in these catalysts, as well as advance fundamental understanding of Fe in the operando electrooxidative environment. The project will study a series of FexNi100-x(OH)y films and subsequently nanoparticle FexNi100-x(OH)y catalysts with soft x-ray absorption spectroscopy, x-ray emission spectroscopy, and resonant inelastic x-ray scattering. The project will focus on the iron L-edge and the oxygen K-edge of selected materials, and will include development of an operando cell for spectroscopy experiments, as well as detailed electrochemical analysis and in vacuo characterization of the catalyst materials.This project was awarded through the “NSF-DFG Lead Agency Activity in Electrosynthesis and Electrocatalysis (NSF-DFG EChem)" opportunity, a collaborative solicitation that involves the National Science Foundation and Deutsche Forschungsgemeinschaft (DFG).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.

本项目旨在确定氢氧化铁镍催化剂材料中铁的结构。这些材料是对下一代能量转换和储存至关重要的关键反应的高活性电催化剂，包括用于生产氢气和电池电极的水电解。了解铁的化学性质有助于设计和合成非贵金属电催化剂，从而支持我们未来的能源经济。这些电催化剂材料也可能在其他未来的电化学技术中发挥作用，包括化学转化和升级回收、生物质转化、水处理和资源回收。因此，该项目及其对了解电化学环境下铁结构如何变化的追求，对于支持国家能源安全以及推动社会向清洁能源技术发展至关重要。所取得的发现将支持广泛的研究活动，重点是类似的非贵金属氧化物和氢氧化物，不仅推进铁镍氢氧化物的科学，而且推进其他类似材料和基于同步加速器的光谱技术，旨在探测其操作环境中的催化剂材料。这种美德合作还将加强国际科学关系，为培养多样化的、具有全球竞争力的科学和工程劳动力做出贡献。本课题的总体研究目标是通过结合材料专业知识和x射线光谱仪器和专业知识，对碱性电氧化条件下的铁电子结构进行实验探测。合作进行的操作实验将使团队能够明确地描述铁的电子状态，并了解FexNi100-x(OH)y纳米催化剂中铁结构变化的时间依赖性和滞后性。重点电催化反应是碱性析氧反应（OER）。该项目将进一步科学地了解这些催化剂中OER活性位点的化学和电子结构，并推进对Fe在操作氧离子电氧化环境中的基本认识。该项目将使用软x射线吸收光谱、x射线发射光谱和谐振非弹性x射线散射技术研究一系列FexNi100-x(OH)y薄膜和随后的纳米颗粒FexNi100-x(OH)y催化剂。该项目将重点关注选定材料的铁l边和氧k边，并将包括用于光谱实验的operando电池的开发，以及详细的电化学分析和催化剂材料的真空表征。该项目是通过“NSF-DFG在电合成和电催化领域的领导机构活动（NSF-DFG EChem）”的机会获得的，这是一项由国家科学基金会和德国研究机构（DFG）参与的合作征集。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。