EAGER: Periodic Binding Energy Modulation for Electrochemical Systems

催化剂是加速化学反应的材料，从而降低化学制造过程的成本、能源消耗和资本设备需求。大多数催化剂研究的重点是寻找最适合加速靶向反应的材料组合。然而，就材料本身可以加速反应的程度而言，存在根本的限制。这项研究将通过在反应事件的时间尺度上对催化剂的操作条件引入动态扰动来绕过这些材料的限制。这一全新的概念将在水分解反应上得到证明，这是一种通过可再生手段产生氢气的重要反应。初步的理论分析表明，通过动态扰动，反应速度可以提高几个数量级，同时也为广泛的化学反应打开了廉价催化剂的大门。材料的催化活性由关键反应中间体的结合能决定，通过能量标度关系描述，这预测了催化活性的最大值-由众所周知的萨巴蒂尔原理表征-仅通过材料设计就可以实现。电化学分解水以产生可再生氢的过程受到这一限制，放氢反应的速率由氢的结合能决定。贵金属催化剂上发现了最佳的氢结合能，这给本已具有经济挑战性的工艺带来了压力，这进一步加剧了这个问题。这项研究将根据翻转事件的时间尺度，研究施加在外加电位中的周期性振荡可以在多大程度上改变电极表面氢的结合能。催化剂在不断振荡的外加电势下工作，其中反应中间产物的结合能不断变化，允许单个催化剂以周期性的方式模拟多种材料的性能。这将使催化剂的设计突破目前因比例关系造成的限制，达到前所未有的催化活性水平。实施这种变革性的操作方法目前受到我们在反应条件下精确地改变催化材料上的结合能的实验能力的限制。具体地说，该项目将探索在标准电化学池中使用交流电位来有效地分解水。这一实验设计还将用于研究热催化与作为结合能调制平台的电化学系统的耦合。该方法可能适用于广泛的具有商业和环境重要性的催化反应。动态催化的概念也将通过首席研究员开发的选修课介绍给研究生。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。

Catalysts are materials that accelerate chemical reactions and thereby reduce the cost, energy consumption, and capital equipment demands of chemical manufacturing processes. Most catalyst research focuses on discovering combinations of materials that are optimal for accelerating the targeted reaction. Fundamental limitations exist, however, regarding the extent to which materials alone can accelerate reactions. The study will side-step such materials limitations by introducing dynamic perturbations to the catalyst's operating conditions at the timescale of reaction events. The radically new concept will be demonstrated on the water splitting reaction - an important reaction for generating hydrogen by renewable means. Preliminary theoretical analysis has suggested that reaction rates can be increased by orders of magnitude via the dynamic perturbations, while also opening the door to less expensive catalysts for a wide range of chemical reactions. The catalytic activity of materials is dictated by the binding energetics of key reaction intermediates, described through energy scaling relationships, which predicts a maximum in the catalytic activity - characterized by the well-known Sabatier principle - achievable through only material design. The electrochemical splitting of water to produce renewable hydrogen suffers from this limitation, where rates of hydrogen evolution reactions are dictated by the binding energy of hydrogen. The problem is further exacerbated by the fact that optimal hydrogen binding energies are found on precious metal catalysts, placing strain on an already economically challenging process. The study will investigate the extent to which the application of periodic oscillations in applied potential, on the timescale of turnover events, can alter the binding energetics of hydrogen on the electrode surface. Operating catalysts under a constantly oscillating applied potential, where binding energetics of reaction intermediates are constantly changing, allows a single catalyst to mimic the performance of multiple materials in a periodic fashion. This will allow for the design of catalysts that break past the current limitations imposed by scaling relationships, to reach unprecedented levels of catalytic activity. Implementing this transformative method of operation is currently limited by our experimental ability to alter binding energetics on catalytic materials with precision under reaction conditions. Specifically, the project will explore the use of alternating potentials in standard electrochemical cells for efficient water splitting. This experimental design will also be used to investigate coupling thermocatalysis with electrochemical systems that serve as a binding energy modulation platform. The approach is potentially applicable to a broad range of catalytic reactions of commercial and environmental importance. The dynamic catalysis concept will also be introduced to graduate students via an elective course developed by the principal investigator.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.