NSF-BSF: Towards a Molecular Understanding of Dynamic Active Sites in Advanced Alkaline Water Oxidation Catalysts

在化学系化学催化项目的支持下，俄勒冈大学的Shannon Boettcher教授正在研究催化材料的化学，用于从电力驱动的水分离中高效、低成本地产生绿色氢气。这项研究的部分动机是该领域的一项重大挑战，即氢气发射，目标是在10年内以每1公斤1美元的价格生产氢燃料。绿氢是整个水分解反应的一半产物。另一半是水氧化，它限制了氢气产生的整体效率，必须通过地球上丰富的催化剂来加速，以提高效率和降低成本。Boettcher的团队已经开发了几种基于镍、铁和钴的催化剂，这些催化剂具有高效的水氧化能力，有望用于氢气技术。有了这笔拨款，他的团队将以分子精度研究决定这些催化剂高性能的潜在化学原理和结构，以及这些化学原理在与工业相关的条件下是否成立。这将通过利用学术伙伴关系来实现，这种伙伴关系有助于快速获得先进的表面表征和计算技术，以及来自行业合作者的实际反馈。除了支持将对催化领域产生重大影响的工作外，这笔赠款还将为即将进入新兴的可再生能源劳动力的研究生和本科生提供关键培训，促进从中学到本科生的继续教育。在这个奖项下，Shannon Boettcher教授和他的研究团队正在研究先进的碱性水氧化催化剂的基本化学描述符。水氧化反应具有动力学缓慢的特点，是制约电解水大规模制氢性能的关键因素。这种氧化反应通常发生在定义不明确的非均相氧化物/氢氧化物的表面，这使得将结构、组成和电子特征与观察到的活性联系起来是困难的。基础催化科学的发现可以解决这些具有挑战性的关系，重要的是，将学到的原理转化为改进的碱性氢气生产技术。有了这笔赠款，Boettcher教授和他的团队正在建立对富含地球活动的Fe-Ni/Co氧氢氧化物的活性中心的生成、保留和损失的基本理解。具体地说，他们将(1)研究新提出的表面铁氧簇合物活性中心的结构和性质如何推动这些过渡金属氧氢氧化物的高活性；(2)开发化学描述符来解释析氧反应(OER)中晶态氧化物(与非晶态氧化物)的表面重组和激活；以及(3)了解动态催化剂表面和铁基活性中心是否以及如何在高温浓缩电解液条件下推动创纪录的OER催化。这项工作试图建立一个更完整的，依赖于温度的，热力学和动力学的理解材料和表面过程的核心，在工业相关条件下的水的氧化。这些目标将通过计算和实验相结合的方式进行研究，重点是在操作条件下进行的实验。以色列海法理工学院的Maytal Caspary-Toroker教授的合作计算工作由美国-以色列双国科学基金会单独资助，有望提供新的和更准确的方法来模拟这些复杂的氢氧化物的热力学和动力学过程。这个美国和以色列的合作项目得到了美国国家科学基金会和以色列双国科学基金会的支持。这个奖项反映了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。

With the support of the Chemical Catalysis program in the Division of Chemistry, Professor Shannon Boettcher of University of Oregon, Eugene is studying the chemistry of catalytic materials for high-efficiency, low-cost generation of green hydrogen from electrically driven water splitting. This research is motivated in part by a grand challenge in the field known as the hydrogen shot, with the target of reaching the production of hydrogen fuel at $1 per 1 kg within one decade. Green hydrogen is obtained as the product of one-half of the overall water splitting reaction. The other half, water oxidation, limits the overall efficiency of hydrogen generation and must be accelerated by earth-abundant catalysts to improve rates and lower costs. Boettcher’s group has developed several catalysts based on nickel, iron, and cobalt with efficient water oxidation ability that are promising for hydrogen technologies. With this grant, his group will study with molecular precision the underlying chemical principles and structures that dictate the high performance of these catalysts and whether these chemical principles hold under industry-relevant conditions. This will be done by leveraging academic partnerships that facilitate rapid access to advanced surface characterization and computational techniques, and practical feedback from industrial collaborators. In addition to supporting work which will have a high impact on the field of catalysis, this grant will also provide key training to graduate and undergraduate students soon to enter the burgeoning renewable energy workforce, facilitate the continuation of educational outreach among students from the middle school to undergraduate level.Under this award, Professor Shannon Boettcher and his research team are studying fundamental chemical descriptors for advanced alkaline water-oxidation catalysts. Water oxidation is characterized by slow kinetics and represents a key constraint in the performance of large-scale hydrogen production through water electrolysis. This oxidation reaction typically occurs on the surface of heterogeneous oxides/oxyhydroxides that are poorly defined, which makes relating structural, compositional, and electronic features to observed activity difficult. Fundamental catalysis science discoveries can address these challenging relations and, importantly, translate learned principles into improved technology for alkaline hydrogen production. With this grant, Prof. Boettcher and his team are building a fundamental understanding of active-site generation, retention, and loss for record-activity earth-abundant Fe-Ni/Co oxyhydroxides. Specifically, they will (1) study how the structure and properties of newly proposed surface Fe-oxo cluster active sites drive high activity in these transition-metal oxyhydroxides; (2) develop chemical descriptors to explain surface restructuring and activation of crystalline oxides (vs. amorphous oxides) for the oxygen evolution reaction (OER); and (3) understand if and how dynamic catalyst surfaces and Fe-based active sites drive record OER catalysis in high-temperature concentrated electrolyte conditions. The work seeks to build a more complete, temperature-dependent, thermodynamic and kinetic understanding of the materials and surface processes central to water oxidation at industrially relevant conditions. These aims will be studied through a combination of computation and experiment, with a significant focus on experiments conducted under operating conditions. Collaborative computational efforts by Prof. Maytal Caspary-Toroker at the Technion in Haifa, Israel, funded separately by the U.S.-Israel Binational Science Foundation, is expected to provide new and more accurate approaches to modeling the thermodynamics and kinetic processes in these complex oxyhydroxides.This collaborative US/Israel project is supported by the US National Science Foundation and the Israel Binational Science Foundation.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.