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.

随着全球能源格局的发展，风能、太阳能和水力发电技术等可再生电力的比例越来越大，电化学过程将成为燃料和化学品的主要来源。氢是许多燃料和化学品的重要组成部分，因此美国的氢需求预计在未来 30 年内将增加 2-5 倍。质子交换膜（PEM）电解槽是大规模、可持续地从水中生产氢气的一项有前途的技术，但开发酸性条件下高效稳定的水氧化催化剂一直是广泛实施的长期障碍。该项目将 1) 研究一类精确调节的催化剂材料，这些材料旨在承受 PEM 电解槽的严酷氧化和酸性条件，并尽量减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，与反应速率和电能的有效利用有关。这项工作的科学成果将提高利用可再生电力生产燃料和化学品的可持续工艺的技术可行性。此外，该研究将与一项可持续计划相结合，以协作开发和实施新课程和课堂活动，强调学生的参与，通过与芝加哥公立高中教师合作，提高来自不同背景的学生的保留率并满足下一代科学标准。该项目重点关注酸性条件下的水氧化，作为一种关键但相对简单的电化学氧化反应，用于钙钛矿氧化物催化剂的反应机制、表面结构演变和失活过程的基础研究，作为其电子和几何结构特性的函数。钙钛矿氧化物结构提供了一个可调平台，可系统地调节催化剂表面和本体的性能，同时与 IrO2 和 Ir/C 基准催化剂相比，使用较低的铱负载量。原位光谱学和动力学同位素研究将探讨反应机制的趋势，并评估与材料特性（氧化态、金属-氧键共价、金属-氧-金属键角等）和反应条件相关的催化剂表面重组程度。显微镜、电化学石英晶体微天平和阻抗谱将监测长期测试的形态、质量变化和电荷传输效应，为各种失活过程提供见解。这项工作还将建立内在的催化剂材料稳定性指标，以补充更普遍的性能稳定性指标，以指导高性能电催化系统的开发。这项工作产生的基本机理见解和结构理解将填补驱动各种选择性电化学氧化反应的金属氧化物催化剂的设计和系统控制的主要知识空白。该奖项反映了 NSF 的法定使命，并通过评估被认为值得支持利用基金会的智力优势和更广泛的影响审查标准。