EAGER: Influence of Ionic Liquids on Product Selectivity in CO2 Electroreduction over Copper Catalysts

二氧化碳（CO2）电还原有望从废二氧化碳和可再生电力中生产燃料和化学品。有机会生产更多的高阶碳氢化合物和醇，但控制产品选择性和具有高活性仍然是需要克服的关键挑战。拟议的探索性研究项目旨在研究使用铜（Cu）和离子液体（ILs）作为co催化剂将二氧化碳转化为有价值的化学品和燃料。这是一个高风险高回报的项目，可能会导致使用可再生电力按需将二氧化碳转化为燃料和化学品的技术的发展。通过在Cu上的CO2电还原中使用il作为稀水添加剂，在实现烃类和醇的高产物选择性方面取得突破是可能的。提出的EAGER项目的中心假设是，在水溶液中使用低浓度的il作为助催化剂可以抑制析氢反应，并提高Cu催化剂上对高阶碳氢化合物和醇的CO2电还原选择性。通过对IL正阴离子对的修饰，IL的热物理性质和化学性质可以得到显著的改变。拟议的研究计划旨在确定IL必须具有的关键性质，以便成为一种良好的助催化剂，以提高对碳氢化合物和醇的法拉第效率。为了验证这一假设，这项工作分为两个主要目标：1)确定影响CO2t电还原法拉第效率的关键IL结构性质；2)确定IL和Cu形态之间是否存在协同效应对CO2电还原法拉第效率的影响。基于结构-性质关系选择il的科学见解将被转移到其他电化学系统，显著影响il的使用方式。所提出的研究计划也可能适用于其他电化学合成方法，如电化学合成氨和电化学加氢，以及其他电化学系统，如电池、燃料电池和废物处理。该提案对教育的广泛影响包括科学劳动力的发展，特别是STEM领域的女性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Carbon dioxide (CO2) electroreduction holds promise for producing fuels and chemicals from waste CO2 and renewable electricity. Opportunities exist to produce more high order hydrocarbons and alcohols, however controlling product selectivity and having high activity remain as the key challenges to overcome. The proposed exploratory research project aims to investigate the use of copper (Cu) and ionic liquids (ILs) as co-catalysts for the conversion of CO2 to valuable chemicals and fuels. This is a high risk-high payoff project that may lead to the development of technologies for on-demand conversion of CO2 to fuels and chemicals using renewable electricity.Breakthroughs in achieving high product selectivity for hydrocarbons and alcohols are possible by using ILs as dilute aqueous additives in CO2 electroreduction over Cu. The central hypothesis of the proposed EAGER project is that the utilization of ILs as co-catalysts at low concentrations in aqueous electrolytes can suppress the hydrogen evolution reaction and enhance CO2 electroreduction selectivity towards higher order hydrocarbons and alcohols on Cu catalysts. By modifying the IL cation-anion pair, the thermophysical and chemical properties of the IL can be altered dramatically. The proposed research plan seeks to identify the key properties an IL must have in order to be a good co-catalyst for the enhancement of the faradaic efficiency towards hydrocarbons and alcohols. To test the hypothesis, the work is split into two main objectives: 1) Identify key IL structure properties that influence faradaic efficiency of CO2t electroreduction, and 2) Determine if there are synergistic effects between IL and Cu morphology on CO2 electroreduction faradaic efficiency. The scientific insights developed for selecting ILs based upon their structure-property relationships will be transferable to other electrochemical systems, significantly impacting the way ILs are used. The proposed research plan may also be applicable to other electrochemical synthesis methods, such as electrochemical ammonia synthesis and electrochemical hydrogenations, and other electrochemical systems, such as batteries, fuel cells and waste treatment. The educational broader impacts of the proposal include scientific workforce development, particularly of women in STEM fields.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.