CAS: Cooperative Site and Electrolyte Design for Optimizing Interfacial Electrokinetics

在化学系化学催化项目的支持下，博士。弗吉尼亚理工学院和州立大学的朱慧媛和辛宏亮正在研究新策略，以提高使用可再生电力回收二氧化碳的催化剂的性能。传统的金属电极，包括贵金属（Au, Ag）和贱金属（Cu, Zn），在减少二氧化碳方面表现出令人鼓舞的性能。然而，该工艺受到能源效率低和产品选择性差的限制。这些过程是在水中进行的，水的竞争性还原为H2是这种低效率的主要原因。本提案解决了这一挑战，使用离子液体作为非水电解质以及设计用于与离子液体一起工作的电极材料。该项目的教育内容包括：(1)对本科生和研究生进行电化学技术、材料表征和分子建模方面的跨学科培训。(2)包括女学生在内的各种未被充分代表的群体参与科学和工程。(3)通过动手演示，向来自不同群体和低收入家庭的K-12学生实施STEM外展计划，说明纳米材料、建模、催化和能源在我们日常生活中的重要性。通过与汉普顿大学的合作，将招募来自未被充分代表的少数群体的本科生暑期实习生参与该项目。在化学系化学催化项目的支持下，博士。弗吉尼亚理工学院和州立大学的朱慧源和洪亮正在研究一种合作位点和电解质调整策略，以合理设计电催化系统，突破能量结垢的限制，特别是铋基双金属纳米催化剂与非水离子液体电解质的电化学CO2还原反应（eCO2RR）。已知的萨巴蒂尔原理是由几何相似位置的吸附-能量缩放关系引起的，通常对可达到的催化性能施加火山状的限制。Zhu-Xin团队假设，通过掺杂和离子液体的杂环阳离子协同调整活性Bi位的p带，可以稳定二氧化碳还原的关键电荷转移中间体，同时抑制竞争性析氢反应（HER）。利用精密合成、电催化、先进表征技术以及分子建模工具的组合，该团队试图揭示纳米颗粒和离子液体电解质界面的结构-反应性关系。这项研究的成功有可能促进对二氧化碳还原化学的基本理解，并为催化剂设计提供指导原则，以解决当前eCO2RR中的挑战。从这个项目中对固体电解质界面的物理化学性质的原子见解可能为其他电催化转化的设计提供指导。除了科学和技术的影响，该项目将培养学生在材料化学，量子化学建模和催化的界面，并为他们在学术界和/或工业界的职业道路做好准备。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。

With the support of the Chemical Catalysis program in the Division of Chemistry, Drs. Huiyuan Zhu and Hongliang Xin of the Virginia Polytechnic Institute and State University are studying new strategies to improve the performance of catalysts that recycle carbon dioxide (CO2) using renewable electricity. Traditional metal electrodes, including precious metals (Au, Ag) and base metals (Cu, Zn), have shown encouraging performance toward CO2 reduction. However, the process is limited by low energy efficiency and poor product selectivity. These processes are conducted in water, and the competing reduction of water to H2 is largely responsible for this inefficiency. This proposal addresses this challenge using ionic liquids as non-aqueous electrolytes together with electrode materials designed to work with ionic liquids. The educational components of the project include the following: (1) The interdisciplinary training of undergraduate and graduate students in electrochemical techniques, materials characterization, and molecular modeling. (2) The involvement of diverse underrepresented groups including female students in science and engineering. (3) The implementation of STEM outreach programs to K-12 students from diverse groups and low-income families through hands-on demonstrations that illustrate the importance of nanomaterials, modeling, catalysis, and energy in our daily life. Undergraduate summer interns from underrepresented minority groups will be recruited to work on this project through a partnership with Hampton University. With the support of the Chemical Catalysis program in the Division of Chemistry, Drs. Huiyuan Zhu and Hongliang Xin of the Virginia Polytechnic Institute and State University are studying a cooperative site and electrolyte tuning strategy for the rational design of electrocatalytic systems to get beyond energy-scaling limitations, specifically for electrochemical CO2 reduction reactions (eCO2RR) on bismuth-based bimetallic nanocatalysts with non-aqueous ionic liquid electrolytes. The known Sabatier principle, arising from the adsorption-energy scaling relations at geometrically similar sites, generally imposes volcano-shaped constraints on the attainable catalytic performance. The Zhu-Xin team hypothesizes that the crucial charge-transfer intermediates toward CO2 reduction can be stabilized by cooperatively tailoring the p-band of active Bi sites via doping and heterocyclic cations of ionic liquids, while the competing hydrogen evolution reaction (HER) is suppressed. Using a combination of precision synthesis, electrocatalysis, advanced characterization techniques, as well as molecular modeling tools, the team seeks to uncover structure-reactivity relationships at the interface of nanoparticles and ionic liquid electrolytes. Success of this proposed research has the potential to advance fundamental understanding of CO2 reduction chemistry and provide guiding principles for catalyst design to address current challenges in eCO2RR. The atomistic insights into physicochemical properties of solid-electrolyte interfaces from this project may provide guidance for the design of other electrocatalytic transformations. Beyond scientific and technical impact, this project will train students at the interface of materials chemistry, quantum-chemical modeling, and catalysis, and prepare them for career pathways in academia and/or industry.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.