CAREER: Designing 3-Dimensional Active Site Environments in Metal-Organic Frameworks for Oxygen Electrochemistry

电化学反应-例如燃料电池中的电化学反应-在实现环境可持续、全球可扩展的氢经济方面发挥着重要作用。 需要催化剂以实际速率促进电化学反应。然而，目前电催化剂的高成本和低效率阻碍了电化学技术的大规模采用。虽然在设计燃料电池催化中重要的氧还原反应的更便宜的替代品方面取得了重大进展，但在过去十年中，性能一直处于稳定状态。 该项目的重点是一类新的结构改性金属有机框架催化剂（MOFs），不受现有催化剂的限制，从而为低成本和高效率的燃料电池技术打开了大门。这项工作的总体目标是建立一个可行的平台，为未来的实验和理论氧还原反应（ORR）的研究基于卟啉的MOFs（PMOFs）。多尺度分子模拟方法（包括密度泛函理论，波函数理论和经典力场）将用于（1）筛选MOF库并识别规避标度关系的3-D活性位点，（2）开发预测受限PMOF孔内溶剂化效应的方法，以及（3）量化对PMOF电催化剂重要的各种传输过程。总之，这些目标将（1）评估使用PMOF进行ORR的潜力，以及（2）产生与各种普遍存在的现象（即，溶剂化、O2传输和电荷转移）。所采用的软件基础设施和理论方法将扩大可以通过计算研究的原子现象的边界;这些方法对纳米多孔材料和多相催化社区都有价值。该研究计划与教育和推广活动紧密结合，重点是开发（1）以研究为导向的分子建模实验室课程和（2）K-12学生基于虚拟现实的化学模块。该研究型课程将有助于培养学生的科学思维，并为学生灌输“终身学习”的理念，而化学模块将提高K-12学生对STEM的参与度和保留率。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

Electrochemical reactions – such as those in fuel cells - play an important role in realizing an environmentally-sustainable, globally-scalable hydrogen economy. Catalysts are required to promote electrochemical reactions at practical rates. However, the high-cost and low-efficiency of current electrocatalysts has prevented large-scale adoption of electrochemical technologies. While significant advances have been made in designing cheaper alternatives for the oxygen reduction reaction important in fuel cell catalysis, performance has plateaued over the past decade. The project focuses on a a new class of structurally-modified Metal Organic Framework catalysts (MOFs) that are not constrained by the limitations of current catalysts, thus opening the door to both lower-cost and higher-efficiency fuel cell technology. The overall goal of this work is to establish bimetallic porphyrin-based MOFs (PMOFs) as a viable platform for future experimental and theoretical oxygen reduction reaction (ORR) studies. Multiscale molecular modeling approaches (including density functional theory, wave function theory and classical force fields) will be used to (1) screen MOF libraries and identify 3-D active sites that circumvent scaling relations, (2) develop methods to predict solvation effects within confined PMOF pores, and (3) quantify the various transport processes that are important for PMOF electrocatalysts. Taken together these objectives will (1) assess the potential of using PMOFs for ORR and (2) generate fundamental insights related to various ubiquitous phenomena (i.e., solvation, O2 transport and charge transfer) in nanoporous materials. The software infrastructure and theoretical approaches employed will expand the boundaries of atomistic phenomena that can be studied computationally; these methods will be valuable to both the nanoporous materials and heterogeneous catalysis communities. The research program is closely integrated with educational and outreach activities that focus on developing (1) a research-oriented Molecular Modeling Lab course and (2) virtual reality-based chemistry modules for K-12 students. The research-oriented course will help create a scientific mindset and instill a “lifetime of learning” for students, while the chemistry modules will improve K-12 student engagement and retention in STEM.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.