Collaborative Research: EAGER: Insights into the Hydrogen Evolution Reaction of Transition Metal Dichalcogenide Nanocrystals by In-situ Electron Paramagnetic Resonance Spectroscopy

合作研究：EAGER：通过原位电子顺磁共振波谱洞察过渡金属二硫族化物纳米晶体的析氢反应

• 批准号: 2302783
• 负责人: Ashwin Ramasubramaniam
• 金额: $ 12.5万
• 依托单位: University of Massachusetts Amherst
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2302783&HistoricalAwards=false
• 关键词: Collaborative; Research; EAGER; Insights; into

The large-scale deployment of hydrogen (H2) as a clean-energy fuel and chemical precursor will require replacing expensive platinum-group metals that catalyze the electrochemical splitting of water via the hydrogen evolution reaction (HER) utilizing renewable electricity. Previous research has identified a class of earth-abundant transition-metal dichalcogenide (TMD) nanocrystalline (NC) electrocatalytic materials that show great promise for the HER. The project will enable further advances in TMD-NC technology by employing a combination of in-situ analytical techniques coupled with theoretical calculations that will provide precise knowledge and understanding of the active catalytic sites in TMD NCs. Together with corresponding mechanistic understanding of the HER, the project will pave the way for the discovery and design of more efficient and less costly HER catalysts, thereby enabling the hydrogen economy. More broadly, the project includes educational, outreach, and workforce training initiatives supporting sustainable technologies for renewable energy and advanced catalysts. The overarching goal of this collaborative Early-concept Grants for Exploratory Research (EAGER) project is to establish an atomic-scale holistic understanding of the interplay between the structure, chemistry, catalytic activity, and mechanisms of the HER on 2H-MoS2 NC catalysts in real time. The team will accomplish this by employing a combination of in-situ electron paramagnetic resonance (EPR) spectroscopy and in-situ x-ray probes coupled with density functional theory (DFT) calculations. EPR spectroscopy will sensitively probe the local environment of paramagnetic catalytic sites, as well as their behavior in catalytic redox processes, under a wide range of operating conditions. In-situ x-ray techniques, complementary to in-situ EPR spectroscopy, will be employed to probe for the non-magnetic (i.e., non-EPR active species and other non-spin related factors) catalytically active HER species, and will enable the separation of the paramagnetic/spin effect from the overall catalytic activity. The changes in the EPR spectral properties, such as signal shape, width, intensity, and g-factor (Zeeman splitting) as a function of potential bias, time, and temperature, will be correlated with the measured HER activities to achieve the central goals of the proposal. DFT calculations will clearly identify the magnetic states of HER-active defect centers, correlate these magnetic states with the local environment of the defect, and calculate corresponding EPR spectra, taking into account the role of adsorbates, electrode polarization, and solvent screening. The outcomes of this research will resolve key challenges in understanding the catalytic activity of TMDs and provide fundamental insights that enable rational design of TMD-based electrocatalysts. Beyond the immediate focus on TMD electrocatalysis, the project will advance in-situ EPR as a promising tool for catalysis science. From the broader impacts perspective, the project will train the Hispanic student population (82%) at the University of Texas at El Paso in renewable energy research. Project-related educational material will be integrated with several outreach activities geared towards broadening participation of army personal and veterans at Fort Bliss in the El Paso region in scientific research. Educational modules on catalysis and its role in renewable energy will be developed and delivered at the University of Massachusetts, Amherst as part of the annual professional development workshops for K-12 STEM educators.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.

大规模部署氢（H2）作为清洁能源燃料和化学前体将需要取代昂贵的铂族金属，这些金属利用可再生电力通过析氢反应（HER）催化水的电化学分解。 先前的研究已经发现了一类地球上储量丰富的过渡金属二硫属化物（TMD）纳米晶（NC）电催化材料，它们在HER方面显示出巨大的前景。 该项目将通过采用原位分析技术与理论计算相结合，进一步推动 TMD-NC 技术的发展，从而提供对 TMD NC 活性催化位点的精确知识和理解。 结合对 HER 相应机理的理解，该项目将为发现和设计更高效、成本更低的 HER 催化剂铺平道路，从而实现氢经济。 更广泛地说，该项目包括支持可再生能源和先进催化剂可持续技术的教育、外展和劳动力培训举措。 该早期概念探索性研究资助 (EAGER) 合作项目的总体目标是对 2H-MoS2 NC 催化剂上 HER 的结构、化学、催化活性和机制之间的相互作用建立原子尺度的整体理解。即时的。该团队将通过结合使用原位电子顺磁共振 (EPR) 光谱和原位 X 射线探针以及密度泛函理论 (DFT) 计算来实现这一目标。 EPR 光谱将在各种操作条件下灵敏地探测顺磁催化位点的局部环境及其在催化氧化还原过程中的行为。原位 X 射线技术作为原位 EPR 光谱的补充，将用于探测非磁性（即非 EPR 活性物质和其他非自旋相关因子）催化活性 HER 物质，并将能够实现将顺磁/自旋效应与整体催化活性分开。 EPR 光谱特性的变化，例如信号形状、宽度、强度和 g 因子（塞曼分裂）作为潜在偏差、时间和温度的函数，将与测量的 HER 活性相关联，以实现中心目标该提案的内容。 DFT 计算将清楚地识别 HER 活性缺陷中心的磁态，将这些磁态与缺陷的局部环境相关联，并计算相应的 EPR 谱，同时考虑吸附物、电极极化和溶剂筛选的作用。这项研究的成果将解决理解 TMD 催化活性的关键挑战，并提供基本见解，使基于 TMD 的电催化剂的合理设计成为可能。 除了直接关注 TMD 电催化之外，该项目还将推动原位 EPR 作为催化科学的一种有前途的工具。 从更广泛的影响角度来看，该项目将对德克萨斯大学埃尔帕索分校的西班牙裔学生群体（82%）进行可再生能源研究方面的培训。 与项目相关的教育材料将与多项外展活动相结合，旨在扩大埃尔帕索地区布利斯堡的陆军人员和退伍军人对科学研究的参与。关于催化及其在可再生能源中的作用的教育模块将在马萨诸塞大学阿默斯特分校开发和提供，作为 K-12 STEM 教育工作者年度专业发展研讨会的一部分。该奖项反映了 NSF 的法定使命，并被认为值得支持通过使用基金会的智力优点和更广泛的影响审查标准进行评估。