Super-Resolution Imaging of Surface Adsorption on Single Nanoparticles for Electrochemical Dechlorination

在化学系大分子、超分子和纳米化学（MSN）项目的支持下，康奈尔大学陈鹏教授正在应用和开发高分辨率成像方法来量化参与电化学加氢脱氯反应的单个钯（Pd）纳米颗粒分子的吸附行为，并确定它们与电化学电位和原始钯纳米颗粒表面结构和尺寸的关系。氯化烃广泛应用于工业和农业，但也对环境造成危害。脱氯是一个关键的解毒过程，其中电化学加氢脱氯更有效，更环保，因为它使用电力驱动反应，而钯纳米粒子是有前途的电催化剂。Chen小组的研究可以产生基础知识，可以帮助改善氯酚的电化学脱氯，氯酚是水生环境中的一大类污染物，从而对社会福祉产生积极影响。成像方法也普遍适用，因此可以广泛影响纳米尺度材料科学的测量科学。对于表面反应，包括纳米颗粒上的电催化，分子-表面相互作用是至关重要的。对于钯纳米粒子催化的电化学加氢脱氯，目前对氯酚和产物酚在钯表面的定量吸附行为知之甚少，而这是电催化循环的关键步骤。在电化学反应条件下，定量吸附通常具有挑战性，特别是在纳米颗粒上，其个体在大小和形状上存在显着差异。所提出的研究可以定量地了解在不同的应用电化学电位下，Pd纳米颗粒上的反应物/中间体/产物吸附的能量学，以及它们与初始表面结构和颗粒尺寸的关系。这些知识可以指导使用动态电化学电位调制来操纵pd基电催化剂上的分子吸附，以提高电化学加氢脱氯的效率。从事该项目的研究生在单分子催化的前沿领域以及通过光学显微镜对非荧光过程进行超分辨率成像的新技术的开发方面获得了经验。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 support from the Macromolecular, Supramolecular and Nanochemistry (MSN) Program in the Division of Chemistry, Professor Peng Chen of Cornell University is applying and developing high-resolution imaging approaches to quantify the adsorption behaviors on single palladium (Pd) nanoparticles of molecules involved in electrochemical hydrodechlorination reactions as well as to determine their relations to the electrochemical potential and the original Pd nanoparticle surface structure and size. Chlorinated hydrocarbons are extensively used in industrial and agricultural applications, but they are also environmental hazards. Dechlorination is a key detoxification process, for which electrochemical hydrodechlorination is more efficient and environmentally friendly by using electric power to drive reactions for which Pd nanoparticles are promising electrocatalysts. The research in the Chen group can generate fundamental knowledge that can help improve electrochemical dechlorination of chlorophenols, a large class of pollutants in aquatic environments, thus positively impact societal well-being. The imaging approaches are also generally applicable and thus can broadly impact measurement science in nanoscale materials science. For surface reactions, including electrocatalysis on nanoparticles, molecule-surface interactions are crucial. For Pd nanoparticle-catalyzed electrochemical hydrodechlorination little is known, however, about the quantitative adsorption behaviors of the chlorophenols and the product phenol on Pd surfaces, which are key steps in the electrocatalytic cycle. It is generally challenging to quantify adsorption under electrochemical reaction conditions, especially on nanoparticles, whose individuals can differ markedly in size and shape. The proposed research can provide quantitative insights into the energetics of reactant/intermediate/product adsorption on Pd nanoparticles at various applied electrochemical potentials and how they are related to the initial surface facet structure and particle size. This knowledge can guide the efforts of using dynamic electrochemical potential modulation to manipulate molecular adsorption on Pd-based electrocatalysts to improve the efficiency of electrochemical hydrodechlorination. The graduate student working on this project is gaining experience at the forefront area of single-molecule catalysis as well as in the development of novel techniques for super-resolution imaging of nonfluorescent processes by optical microscopy.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.