CAS: Collaborative Research: Steering Proton-Coupled Electron Transfer Processes for Energy Conversion at the Metal Electrode/Porous 3D Material Interface

在化学系化学催化计划的支持下，波士顿学院的Matthias Waegele教授和Junwei(Lucas)Bao教授，以及波士顿马萨诸塞大学的Mariam Ismail教授正在研究如何精确地修饰电极以控制电催化反应以储存能量。电催化过程可以从二氧化碳或生物质等丰富的可再生原料中以液体或气体燃料的形式储存来自可再生能源的电能。采用这项技术的一个主要障碍是这些反应的产品选择性很差。这些反应是复杂的，发生在涉及液体(电解液)和固体(电极)的界面上。在这项工作中，项目组将通过在电极上涂上一种名为金属有机骨架(MOF)的特殊类型的多孔材料来修改这种界面，从而改变电催化活性。该项目团队将使用光谱学和先进的计算机模拟来从分子水平深入了解MOF覆盖层对三个对可再生燃料合成至关重要的模型反应的影响：将水转化为氢，将二氧化碳转化为一氧化碳，以及将生物质转化为有价值的化学品和燃料。本研究的结果将为电催化反应的选择性控制提供依据。此外，该小组将开展协同活动，以促进招募和留住STEM中任职人数不足的群体。具体地说，作为暑期项目的一部分，该团队将邀请女高中生和未被充分代表的本科生参与这项研究，这将使参与者接触到合成、分析化学和模拟技术领域的最先进的可再生能源研究。在这个项目中，波士顿学院的Matthias Waegele和Junwei(Lucas)Bao以及波士顿马萨诸塞大学的Mariam Ismail正在研究和设计金属电极/多孔3D材料界面的3D活性部位，以促进质子耦合电子转移(PCET)过程的理想反应路径，用于能量存储和转换。为此，该团队将在金属电极(铂和金)上覆盖结晶金属-有机骨架(MOF)覆盖层，并研究MOF覆盖层对PCET工艺的影响。通过MOF的无机节点和有机连接物的系统变化，该团队将致力于了解MOF的化学和物理性质对PCET的影响。该项目将专注于放氢反应(HER)和将二氧化碳还原为一氧化碳。振动光谱和拉曼光谱将用于表征催化条件下的金属电极/MOF界面。从这些测量中提取的关键性质将包括界面pH、双电层电荷、MOF-中间体相互作用、界面水结构以及金属表面MOF的局部结构。计算机模拟将绘制出最低能量的反应路径。在这些调查的基础上，该项目的目标是建立牢固的界面性质-反应性关系。这样的设计规则将有助于指导选择协同的3D材料、电解液和反应条件，以指导在水溶液中的PCET反应，从而也支持发现有效和选择性的可再生燃料形成途径。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。

With the support of the Chemical Catalysis program in the Division of Chemistry, Professors Matthias Waegele and Junwei (Lucas) Bao of Boston College, and Professor Mariam Ismail of the University of Massachusetts, Boston are studying how to precisely modify electrodes to control electrocatalytic reactions for energy storage. Electrocatalytic processes can store electrical energy from renewable energy sources in the form of liquid or gaseous fuels from abundant, renewable feedstocks such as carbon dioxide or biomass. A principal hurdle for the adoption of this technology is the poor product selectivity of these reactions. These reactions are complex and occur at an interface involving a liquid (the electrolyte) and a solid (the electrode). In this work, the project team will modify this interface, and thus the electrocatalytic activity, by coating the electrodes with a special class of porous material known as metal-organic frameworks (MOFs). The project team will use spectroscopy and advanced computer simulations to gain molecular-level insights into the effects of the MOF overlayers on three model reactions that are central for renewable fuel synthesis: The conversion of water to hydrogen, the conversion of carbon dioxide to carbon monoxide, and conversion of biomass to valuable chemicals and fuels. The results of this research will provide insight into the control of selectivity of electrocatalytic reaction. Further, the team will engage in synergistic activities aimed at promoting the recruitment and retention of underrepresented groups in STEM. Specifically, the team will involve female high-school students and underrepresented undergraduate minority students in this research as part of a summer program, which will expose the participants to state-of-the-art renewable energy research in the areas of synthesis, analytical chemistry, and simulation techniques.On this project, Matthias Waegele and Junwei (Lucas) Bao of Boston College and Mariam Ismail of the University of Massachusetts, Boston are studying and designing 3D active sites at the metal electrode/porous 3D material interface to facilitate desirable reaction pathways of proton-coupled electron transfer (PCET) processes for energy storage and conversion. To this end, the team will coat metal electrodes (Pt and Au) with crystalline metal-organic framework (MOF) overlayers and investigate the effects of the MOF overlayers on PCET processes. Through systematic variation of the inorganic nodes and organic linkers of the MOFs, the team will aim to understand the effect of the MOF’s chemical and physical properties on PCET. The project will focus on the hydrogen evolution reaction (HER) and the reduction of carbon dioxide to carbon monoxide. Vibrational and Raman spectroscopies will be used to characterize the metal electrode/MOF interface under catalytic conditions. Key properties to be extracted from these measurements will include the interfacial pH, electric double layer charging, MOF-intermediate interactions, interfacial water structure, and local structure of the MOF at the metal surface. Computer simulations will map minimum-energy reaction pathways. On the basis of these investigations, the project aims to establish robust interfacial property-reactivity relationships. Such design rules would serve to guide the choice of synergistic 3D material, electrolyte, and reaction conditions to steer PCET reactions in aqueous electrolytes, and thereby also support the discovery of efficient and selective pathways for renewable fuels formation.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.