CAREER: Probing and Controlling Acidic Electrocatalytic Oxidation Mechanisms and Catalyst Degradation Processes

职业：探测和控制酸性电催化氧化机制和催化剂降解过程

• 批准号: 2144365
• 负责人: Linsey Seitz
• 金额: $ 60.32万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2027-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2144365&HistoricalAwards=false
• 关键词: CAREER; Probing; Controlling; Acidic; Electrocatalytic

As our global energy landscape evolves to incorporate a greater fraction of renewable electricity from sources such as wind, solar, and hydroelectric technologies, electrochemical processes will become a major source of fuels and chemicals. Hydrogen is a critical component of many fuels and chemicals, such that hydrogen demand in the US is projected to increase 2-5 times over the next 30 years. Proton exchange membrane (PEM) electrolyzers are a promising technology for large-scale, sustainable production of hydrogen from water, but development of efficient and stable catalysts for water oxidation in acidic conditions has been a longstanding roadblock for widespread implementation. The project will 1) investigate a class of precisely tuned catalyst materials that are designed to withstand the harsh oxidative and acidic conditions of PEM electrolyzers with minimal use of expensive and strategic precious metals, and 2) characterize critical relationships between catalyst structures and reaction mechanisms, as related to reaction rates and efficient utilization of electrical energy. The scientific outcomes of this work will lead to improved technological feasibility of sustainable processes for production of fuels and chemicals from renewable electricity sources. Furthermore, the research will be integrated with a sustainable plan for collaborative development and implementation of new curriculum and classroom activities that emphasize student engagement to improve retention of students from diverse backgrounds and fulfill Next Generation Science Standards, via work with Chicago Public High School teachers.This project focuses on water oxidation in acidic conditions as a critical, yet comparatively simple, electrochemical oxidation reaction for fundamental study of reaction mechanisms, surface structure evolution, and deactivation processes for perovskite oxide catalysts as a function of their electronic and geometric structure properties. Perovskite oxide structures provide a tunable platform for systematically modulating properties of catalysts both at the surface and in the bulk, while utilizing lower loadings of iridium compared to IrO2 and Ir/C benchmark catalysts. In situ spectroscopy and kinetic isotope studies will probe trends in reaction mechanisms and assess extent of catalyst surface reorganization with relation to material properties (oxidation states, metal-oxygen bond covalency, metal-oxygen-metal bond angle, etc.) and reaction conditions. Microscopy, electrochemical quartz crystal microbalance, and impedance spectroscopy will monitor morphology, mass changes, and charge transport effects as a result of long-term testing to provide insights to various deactivation processes. This work will also establish intrinsic catalyst material stability metrics to complement more ubiquitous performance stability metrics to guide development of high performance electrocatalytic systems. Fundamental mechanistic insights and structural understanding arising from this work will fill major knowledge gaps for design and systematic control of metal oxide catalysts that drive a wide range of selective electrochemical oxidation reactions.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.

随着我们的全球能源景观的发展，从风，太阳能和水力发电技术等来源中纳入了更大的可再生电力，电化学工艺将成为燃料和化学物质的主要来源。氢是许多燃料和化学物质的关键组成部分，因此在未来30年内，美国的氢需求预计将增加2-5倍。质子交换膜（PEM）电解剂是一种有前途的技术，可用于从水中进行大规模，可持续产生氢的生产，但是在酸性条件下开发有效且稳定的催化剂来用于水氧化，这是长期以来的障碍，用于广泛实施。该项目将1）研究一类精确调谐的催化剂材料，这些材料旨在承受PEM电解液的苛刻氧化和酸性条件，而最少使用昂贵的战略性贵金属，2）表征催化剂结构和反应机制之间的关键关系，与反应速率和有效的电能的有效利用相关。这项工作的科学结果将导致可持续过程从可再生电源生产燃料和化学物质的可持续过程的技术可行性。此外，这项研究将与可持续的计划集成，以合作开发和实施新的课程和课堂活动，通过与芝加哥公立高中教师的工作，强调学生参与，以提高学生的参与度，以提高学生对不同背景的学生的保留，并履行下一代科学标准，这些项目侧重于对酸性的氧化氧化的氧化氧化，以供酸性的氧化氧化，以相比的反应，依赖于酸性的氧化，以相比的氧化能力，以相比的反应，以供酸性的氧化，以供酸性的氧化。钙钛矿氧化物催化剂的进化和失活过程是其电子和几何结构特性的函数。钙钛矿氧化物结构为在表面和散装中系统地调节催化剂的性能提供了可调节的平台，同时与IRO2和IRO/C基准催化剂相比，使用了少量的虹膜负载。原位光谱和动力学同位素研究将探测反应机制中的趋势，并评估催化剂表面重组的程度与材料特性（氧化态，金属氧键的价值，金属氧基 - 金属键角等）和反应条件。显微化学石英晶体微量平衡和阻抗光谱法将由于长期测试而监测形态，质量变化和电荷传输效应，从而为各种失活过程提供见解。这项工作还将建立固有的催化剂材料稳定性指标，以补充更多无处不在的性能稳定性指标，以指导高性能电催化系统的开发。这项工作产生的基本机械洞察力和结构理解将填补对金属氧化物催化剂的设计和系统控制的主要知识空白，这些催化剂推动了广泛的选择性电化学氧化反应。该奖项反映了NSF的法定任务，并通过该基金会的知识优点和广泛的影响来评估NSF的法定任务。