RUI: CAS: Nitrate/Nitrite Reduction Utilizing Hemilability and Redox-Activity

美国国家科学基金会化学部的化学催化计划支持西华盛顿大学约翰·吉尔伯森教授和蒂莫西·科瓦尔奇克教授的研究项目。他们的项目专注于开发解决化肥造成的污染的新方法。虽然化肥中的氮基化合物有助于作物生长，但它们可以渗入自然水道、湖泊和海洋，使藻类大量繁殖，从而耗尽其他植物生存所需的氧气，从而造成“死区”。为了防止这种死区，这项研究项目使用催化剂从水中去除这些含氮化肥。这项研究将计算机计算与实验室实验相结合，建议如何将这些化合物转化为污染较少的形式。特别令人感兴趣的是一种新的铁基催化剂家族，旨在选择性地攻击最有问题的氮化合物，而不影响其他化合物。新的催化剂正在由一个本科生团队准备和测试。这种实践培训提供了从事技术职业所必需的科学技能。本科生研究人员的实验室培训与沟通和协作技能培训相辅相成。包括一系列广泛的外联活动，包括为来自不同背景的学生建立一个平台，让他们参与多个机构层面的科学讨论。这种培训有助于就如何处理研究问题和解释数据进行公开对话。这项工作通过与一对相辅相成的科学和能源扫盲活动相结合，为社区带来好处。氧阴离子作为生命系统的基石发挥着至关重要的作用。例如，亚硝酸盐和硝酸盐是生物地球化学氮循环的中心。通过过度使用化肥等人为干预，历史上主导这一周期的平衡/不平衡正在发生变化。在化学系化学催化项目的支持下，西华盛顿大学的John Gilbertson教授和Timothy Cotalczyk教授正在开发将半活性和基于配体的氧化还原活性相结合的催化剂，以研究亚硝酸盐和硝酸盐的还原。通过开发一系列在二次配位球上具有半亲水Lewis碱和含硼Lewis酸的模块化吡啶二亚胺(PDI)配体，这些基团正在调整空间位数、PKA、酸度和基于配体的还原电位，以生成氧化还原匹配的氮氧化物还原络合物。该项目通过提供跨学科的科学和专业培训来支持本科生研究人员。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。

The Chemical Catalysis Program in the Division of Chemistry of the National Science Foundation supports the research project of Professors John Gilbertson and Timothy Kowalczyk at Western Washington University. Their project focuses on developing new ways of addressing pollution caused by fertilizers. While nitrogen-based compounds in fertilizers help crops grow, they can leach into natural waterways, lakes, and oceans fertilizing blooms of algae that deplete the oxygen which is required for other plants to live thus causing “dead zones”. To prevent such dead zones, this research project employes catalysts to remove these nitrogen-containing fertilizers from the water. The research combines computer calculations with laboratory experiments to suggest how these compounds can be converted to less polluting forms. Of particular interest is a new family of iron-based catalysts that are designed to selectively attack the most problematic nitrogen compounds, leaving others unaffected. The new catalysts are being prepared and tested by a team of undergraduate students. This hands-on training provides the scientific skills necessary for technical careers. The laboratory training of the undergraduate researchers is complemented by training in communication and collaboration skills. An extensive set of outreach activities are included, including the construction of a platform for students from diverse backgrounds to engage in scientific discussions across multiple institutional levels. This training facilitates an open dialogue of how research questions are approached and data interpreted. This work delivers benefits to the community through its integration with a complementary pair of science and energy literacy initiatives.Oxoanions play a vital role as the building blocks of living systems. For example, nitrite and nitrate are central to the biogeochemical Nitrogen Cycle. Through human intrusions such as the overuse of fertilizers, the equilibrium/disequilibrium that has historically governed this cycle is changing. With support from the Chemical Catalysis Program in the Division of Chemistry, Professors John Gilbertson and Timothy Kowalczyk at Western Washington University are developing catalysts that integrate hemilability and ligand-based redox activity to study nitrite and nitrate reduction. By developing a family of modular pyridinediimime (PDI) ligands with hemilabile Lewis bases and boron-containing Lewis acids in the secondary coordination sphere, the groups are tuning the sterics, pKa, Acidity Number, and ligand-based reduction potentials for the production of complexes that are redox-matched for NOx- reduction. The project supports undergraduate researchers by providing interdisciplinary scientific and professional training.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.