Redox Cycling Driven Transformation of Manganese Oxide Minerals

在化学学部环境化学科学（ECS）项目的支持下，乔治亚理工学院的唐元志和陈海龙将研究重复氧化还原反应对锰氧化物结构的影响。这些研究将利用x射线衍射工具来阐明与氧化/还原循环时锰氧化物的形态、分子结构和性能变化相关的关键细节。该项目包括开发整合环境、化学和材料概念的高中课程材料。它将促进培养化学/地球科学领域的下一代科学家，并强调增加来自代表性不足群体的团队成员在科学领域的参与。Drs。唐和陈将把研究成果纳入环境与材料科学的本科和研究生教学中。研究小组将开展社区外展活动，在一年一度的亚特兰大科学节上向公众展示矿物和矿物属性。锰氧化物几乎存在于所有环境中。它们对许多重要金属、营养物质、有机化合物和污染物的生物地球化学循环具有重要影响。在自然环境和长时间尺度上，这些矿物质通常经历许多氧化和还原循环。然而，这种循环氧化还原循环对锰氧化物结构和转化的影响仍不为人所知。重要的是填补这一知识缺口，以便开发更好的预测模型，以了解污染物和营养物质在自然环境中的命运。本项目将系统研究锰氧化物在循环氧化还原反应中的结构转变。研究小组将使用电化学方法来控制电子流的速率和大小。他们将利用基于同步加速器的x射线表征来研究与这些氧化还原循环相关的动力学、机制和反应途径。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 Environmental Chemical Sciences (ECS) Program of the Chemistry Division, Yuanzhi Tang and Hailong Chen of the Georgia Institute of Technology will investigate the impact of repeated oxidation-reduction reactions on the structure of manganese (Mn) oxides. The studies will utilize the tools of X-ray diffraction to elucidate key details associated with the change in morphology, molecular structure and properties of manganese oxides when subjected to these oxidation/reduction cycles. The project includes developing high school curriculum materials that integrate environmental, chemical, and materials concepts. It will promote the training of the next generation of scientists at the chemistry/geoscience interface and do so with an emphasis on increasing the participation of team members from underrepresented groups in science. Drs. Tang and Chen will incorporate the research results into undergraduate and graduate teaching on environmental and materials sciences. The research team will develop community outreach activities to showcase mineral and mineral properties to the general public at the annual Atlanta Science Festival.Manganese oxides exist in nearly all environmental settings. They have significant influence on the biogeochemical cycling of many important metals, nutrients, organic compounds, and contaminants. In natural environments and over long time scales, these minerals commonly experience many cycles of oxidation and reduction. Still, much remains unknown about the influence of such cyclic oxidation-reduction cycles on the structure and transformation of Mn oxides. It is important to fill this knowledge gap needs in order to develop better predictive models for understanding the fate of contaminants and nutrients in the natural environment. This project will systematically examine the structural transformation of Mn oxides during cyclic oxidation-reduction reactions. The research team will use electrochemical methods to control the rate and magnitude of electron flow. They will utilize synchrotron-based X-ray characterization to investigate the kinetics, mechanisms, and reaction pathways associated with these redox cycles.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.