CAREER: Electrochemically Mediated Carbon Dioxide Separation via Non-Aqueous Proton-Coupled Electron Transfer

职业：通过非水质子耦合电子转移进行电化学介导的二氧化碳分离

• 批准号: 2237096
• 负责人: Yayuan Liu
• 金额: $ 51.57万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2028-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2237096&HistoricalAwards=false
• 关键词: CAREER; Electrochemically; Mediated; Carbon; Dioxide

The efficient capture of carbon dioxide (CO2) from stationary emitters and ambient air is vital in meeting climate targets. However, the conventional thermochemical methods for CO2 capture are energy-intensive, cost-prohibitive, and fossil fuel-dependent. On the other hand, emerging carbon capture approaches driven by electrochemical reactions promise mild operating conditions, flexibility for coupling to intermittent renewable energy resources, and could accommodate the multi-scale nature of carbon capture needs due to their modularity. Nevertheless, the practical deployment of existing electrochemical carbon capture processes remains hindered by issues such as oxygen sensitivity and evaporative loss. Correspondingly, this project explores a new concept for carbon capture modulated by electrochemical stimuli. The concept involves the generation of low-volatility, air-stable CO2 sorbents at an electrode surface, followed by CO2 capture in an absorber unit and the subsequent CO2 release upon switching the polarity of the electrode. The goal is to understand and ultimately harness control over the thermodynamics, reaction kinetics, and transport properties of the model electrochemical system, utilizing a multi-modal toolkit of materials synthesis, characterization, and electroanalysis. The broader impacts involve education and mentoring activities from high school through graduate levels to prepare a young generation of engineers with an interdisciplinary skillset essential to solving humanity’s sustainability challenges, which include developing high school laboratory modules on carbon capture and integrating advances in separation methods and interfacial sciences into the university’s chemical engineering curriculum. The project aims to research an electrochemical interface composed of redox-tunable Brønsted base moieties that can undergo proton-coupled electron transfer (PCET) in non-aqueous electrolytes for the reversible (re)generation of air-stable CO2 sorbents. At the molecular level, the relationship between molecular structure, Brønsted basicity, and PCET energetics will be delineated to inform the rational design of carbon capture chemistry. At the material level, microporous electrodes will be synthesized to examine the interplay between electrode microstructure and the corresponding mass and charge transport behaviors. The impact of the electrolyte environment on the PCET and CO2 chemisorption kinetics will also be systematically investigated via (electro)analytical techniques. Finally, the CO2 separation concept will be evaluated in a bench-scale prototype, and a combined experimental and modeling effort will shed light on possible degradation mechanisms and bottlenecks to promote rationally motivated improvement strategies.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.

从固定排放者和环境空气中有效捕获二氧化碳（CO2）对于实现气候目标至关重要。然而，传统的二氧化碳捕获热化学方法是能源密集型的，成本过高，并且依赖化石燃料。另一方面，由电化学反应驱动的新兴碳捕获方法承诺温和的操作条件，与间歇性可再生能源耦合的灵活性，并且由于其模块化，可以适应碳捕获需求的多尺度性质。然而，现有的电化学碳捕获工艺的实际部署仍然受到诸如氧敏感性和蒸发损失等问题的阻碍。相应地，本项目探索了电化学刺激调节碳捕获的新概念。该概念涉及在电极表面产生低挥发性，空气稳定的二氧化碳吸附剂，然后在吸收器单元中捕获二氧化碳，随后在切换电极极性时释放二氧化碳。目标是了解并最终利用材料合成、表征和电分析的多模态工具包，控制模型电化学系统的热力学、反应动力学和输运性质。更广泛的影响包括从高中到研究生阶段的教育和指导活动，以培养具有跨学科技能的年轻一代工程师，这些技能对解决人类可持续性挑战至关重要，包括开发高中碳捕获实验室模块，将分离方法和界面科学的进步整合到大学的化学工程课程中。该项目旨在研究一种由氧化还原可调Brønsted碱基组成的电化学界面，该界面可以在非水电解质中进行质子耦合电子转移（PCET），用于可逆（再）生成空气稳定型二氧化碳吸附剂。在分子水平上，将描述分子结构、Brønsted碱度和PCET能量学之间的关系，为碳捕获化学的合理设计提供信息。在材料层面，将合成微孔电极，以研究电极微观结构与相应的质量和电荷输运行为之间的相互作用。电解质环境对PCET和CO2化学吸附动力学的影响也将通过（电）分析技术系统地研究。最后，二氧化碳分离概念将在一个实验规模的原型中进行评估，并结合实验和建模工作将揭示可能的降解机制和瓶颈，以促进合理动机的改进策略。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。