Collaborative Research: Regulating homogeneous and heterogeneous mechanisms in six-electron water oxidation

匹兹堡大学的John A.Keith教授和Drexel大学的Maureen H.Tang教授在化学系化学催化计划的支持下，进行了一项实验和理论相结合的研究，以了解水的电催化氧化形成臭氧的过程。臭氧的最大用途是在制药、合成润滑剂和其他商用有机化合物的制备中。臭氧也被用来杀灭市政饮用水中的细菌。电化学臭氧生产包括非均相(在电极表面)和均相(在溶液中)的化学步骤。具体地说，这项研究试图通过使用计算催化建模与实验测量相结合的方式来理解这个过程是如何以及为什么发生的。一旦机理确定，最近开发的计算高通量筛选方法将被用于从理论上设计和实验验证用于产生臭氧的催化剂。该项目预计将提供有关电催化反应的基础知识。预计成功将满足社会对这种商品的基本需求。学生接受实验和理论化学研究工具相结合的培训。代表不足群体人口较多的城市地区的中学被列为推广计划的目标。继续并扩大利用多样性办公室和德雷克塞尔林迪中心设施的现有活动。该项目致力于通过电催化氧化水来产生臭氧。具体地说，这项研究试图了解电化学步骤是如何以及为什么在溶液相(均相)和电极表面(非均相)发生的。在考虑局部溶剂化环境的同时，计算催化模拟与实验的非原位电子顺磁共振研究、微分电化学质谱学和光催化技术相结合，以发展对电化学臭氧产生机制(EOP)的完整理解。讨论了三个基本的科学问题：1)导致臭氧的关键EOP中间体是什么？它是如何产生的？2)为什么某些催化剂材料和配置独特地提高了EOP的选择性？以及3)提高对机理的理解能否带来新的和改进的EOP催化剂？该项目有望为理解涉及均相和非均相步骤的基本电催化反应机理奠定重要的基础工作。这一奖项反映了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。

Professor John A. Keith of the University of Pittsburgh and Professor Maureen H. Tang of Drexel University are supported by the Chemical Catalysis Program of the Division of Chemistry to conduct a combined experimental/theoretical study to understand the formation of ozone through the electrocatalytic oxidation of water. The largest use of ozone (O3) is in the preparation of pharmaceuticals, synthetic lubricants, and other commercially-useful organic compounds. Ozone is also used to kill bacteria in municipal drinking water. Electrochemical ozone production involves heterogeneous (on electrode surfaces) and homogeneous (in solution) chemical steps. Specifically, the study seeks to understand how and why this process occurs the way it does through the use of computational catalysis modeling in tandem with experimental measurements. Once the mechanism is established, recently developed computational high-throughput screening methods will be used to theoretically design and experimentally validate catalysts for ozone production. The project is expected to deliver fundamental knowledge on electrocatalytic reactions. Success is expected to satisfy the basic societal need for such a commodity. Students are trained in combined experimental and theoretical chemistry research tools. Middle schools in urban areas with high populations of underrepresented groups are targeted with outreach plans. Existing activities that leverage the facilities of the Office of Diversity and Drexel's Lindy Center are continued and expanded. The project addresses the production of ozone via electrocatalytic oxidation of water. Specifically, the study seeks to understand how and why electrochemical steps occur in solution phase (homogeneously) and on an electrode surface (heterogeneously). Computational catalysis modeling while accounting for local solvation environments are combined with experimental ex situ electron paramagnetic resonance studies, differential electrochemical mass spectroscopy, and photocatalysis techniques to develop a complete understanding of the electrochemical ozone production mechanism (EOP). Three basic scientific questions are addressed: 1) what is the key EOP intermediate that leads to ozone and how is it generated? 2) why do certain catalyst materials and configurations uniquely improve EOP selectivity? and 3) can improved mechanistic understanding lead to novel and improved EOP catalysts? This project is expected to lay important foundational work that is needed to understand fundamental electrocatalysis reaction mechanisms that involve homogeneous and heterogeneous steps. It is also expected to validate EOP as a means to sustainable production of ozone.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.