Collaborative Research: Modulating Single-Atom Catalytic Centers in Well-Defined Metal Oxide Nanocrystal Surfaces for Oxygen Evolution Reaction

开发以化石燃料为基础的能源的可再生替代品是美国面临的最关键的科学挑战之一。电催化是连接可再生能源(太阳能、水能和风能等)的基石。化学转化是能量储存和转化的核心。该项目将开发一种新兴的电催化材料，以最大限度地提高从水中生产氢燃料的效率。该项目的成果对氢燃料技术的发展做出了重大贡献，并支持国家努力使能源供应多样化，减少对不可再生能源的依赖。该项目产生的知识将促进对催化和其他技术(包括电池和传感器)的总体理解和研究。这项研究辅以一系列教育和推广活动，主要针对K-12和来自代表性不足群体的本科生，以提高他们对科学家和工程师职业的兴趣。该项目代表着一项跨学科和跨研究所的努力，旨在开发用于放氧反应(OER)的明确定义的单原子催化剂--放氧反应是水电解槽和可再生氢气生产的关键屏障反应。该项目整合了合作研究人员在实验和计算催化方面的各自专业知识，以解决对OER催化至关重要的三个问题：如何识别或构建定义明确的OER催化中心；如何在该中心明确描述OER的原子机制；以及如何利用对机理的理解和合成技术来微调催化中心，以实现最佳动力学。主要的策略是通过计算设计和精确地合成定义明确且化学稳定的金属氧化物纳米晶表面的单原子催化中心(例如钴)，从而通过机理理解和合成调制来优化OER性能。具体工作包括：(1)合成具有不同和可控制的金属氧化物相、组成和表面面的钴单原子催化中心；(2)通过计算和实验相结合的方法了解反应机理和动力学对组成和原子结构的依赖；以及(3)利用这种理解对合理的组成进行电子扫描，结合基于验证的计算模型的机器学习，然后对预测的最佳候选者进行实验合成，以确定最佳的单原子和金属氧化物组成。教育外展活动包括本科生和K-12年级的学生参加研究人员实验室的暑期研究实习，以及调查人员和研究生访问少数群体服务的合作机构，根据他们的研究提供短期课程。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The development of renewable alternatives to fossil fuel-based energy is one of the most critical scientific challenges of the United States. Electrocatalysis is a cornerstone to bridging renewable electrical energy resources (solar, hydro, and wind power, etc.) with chemical transformations central to energy storage and conversion. The project will develop an emerging class of electrocatalytic materials to maximize the efficiency of hydrogen fuel production from water. The outcome of this project makes a major contribution to hydrogen fuel technology development and supports the nation’s efforts to diversify energy supply and reduce the dependence on non-renewable energy sources. The knowledge generated from this project will advance general understanding and research in catalysis and other technologies, including batteries and sensors. The research is supplemented by a range of educational and outreach activities primarily for K-12 and undergraduate students from underrepresented groups to increase their interest in careers as scientists and engineers.This project represents a cross-disciplinary and cross-institute effort to develop well-defined single atom catalysts for the oxygen evolution reaction (OER) - the key barrier reaction for water electrolyzer and renewable hydrogen production. The project integrates the co-investigators' respective expertise in experimental and computational catalysis to address three questions paramount to OER catalysis: how to identify or construct well-defined catalytic centers for OER; how to delineate unambiguously the atomistic mechanism for OER at this center; and how to leverage the mechanistic understanding and the synthetic technique to fine-tune catalytic centers for optimal kinetics. The primary strategy is to computationally design and precisely synthesize single-atom catalytic centers (e.g. cobalt) in the surface of well-defined and chemically stable metal oxide nanocrystals, thereby optimizing the OER performance through mechanistic understanding and synthetic modulation. Three specific tasks are included: (1) synthesizing cobalt single-atom catalytic centers with diverse and controllable metal oxide phase, composition, and surface facets; (2) understanding dependence of the reaction mechanism and kinetics on composition and atomic structure through a combination of computational and experimental approaches; and (3) using this understanding to conduct in silico scanning of reasonable compositions, combined with Machine Learning based on the validated computational model, followed by experimental synthesis of the predicted best candidates to identify the optimal single-atom and metal oxide compositions. Educational outreach involves the participation of undergraduate and K-12 students in summer research internships in the investigators’ laboratories as well as visits by the investigators and graduate students to the minority-serving partner institutions to deliver short courses based on their research.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.