Metal Oxynitrides: Tuning Metal-N and Metal-O Interactions for Improved Electrocatalytic Properties at the Liquid/Solid Interface

氨生产对农业至关重要，但目前是通过能源密集型工艺生产的，该工艺也会产生大量的CO2。 地球上丰富的过渡金属氧化物和氮氧化物是用作从二氮合成氨的催化剂的主要材料，二氮占地球大气的78%。 这些材料的广泛使用，这些技术上重要的应用提出了一个重大的挑战，然而，作为氮氧化物表面化学在复杂的电解质/固体界面的原子水平的理解没有得到很好的理解。 有了这个项目，在材料研究部的固态和材料化学和陶瓷计划的支持下，教授。Cundari，D 'Souza和Kelber以及他们在北德克萨斯大学（UNT）的研究小组将研究与通过更节能的途径将二氮转化为氨相关的基本化学相互作用。 这些研究将有助于了解化学和材料因素，这些因素对于优化从二氮生产氨的新材料以及其他重要工业反应的应用至关重要。 参与的学生研究人员将学习广泛的实验和计算技能，PI将与其他UNT教师和学生合作，以英语和西班牙语就重要的化学主题进行简短的演示，以提高高中生对追求化学和其他STEM职业的兴趣。消耗大量能量并产生大量CO2的Bosch工艺以及设计新材料以提供环境/能量友好的替代品来生产N2可以对农业、节能和环境产生重大影响。地球上丰富的过渡金属氧化物和氮氧化物在能源和环境应用中的兴趣正在迅速增长，但是N，O和金属中心在N2还原中的基本作用还没有得到很好的理解。该项目由材料研究部的固态和材料化学与陶瓷计划支持，将研究与将二氮还原为氨以及其他电催化过程（如氢和氧的形成）相关的电解质/固体界面的基本相互作用。 电化学方法，结合原位和operando表面科学探针，将探测在电解质/氮氧化物界面的基本相互作用，控制催化效率和选择性。 实验研究将得到支持和指导的理论努力集中在N-支撑与O-支撑金属中心的反应途径的能量。 参与的学生将学习实验和理论方法，这将提高他们在学术和工业研究环境中的能力。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Non-technical SummaryAmmonia production is vital to agriculture but is currently produced by an energy-intensive process that also produces significant amounts of CO2. Earth-abundant transition metal oxides and oxynitrides are the primary materials used as catalysts for synthesis of ammonia from dinitrogen, which comprises 78% of Earth’s atmosphere. Widespread use of these materials for such technologically important applications poses a significant challenge, however, as the atomic-level understanding of oxynitride surface chemistry at the complex electrolyte/solid interface is not well understood. With this project, supported by the Solid State and Materials Chemistry and Ceramics programs in the Division of Materials Research, Profs. Cundari, D’Souza and Kelber and their research groups at the University of North Texas (UNT) will investigate fundamental chemical interactions relevant to the conversion of dinitrogen to ammonia via more energy-efficient routes. The studies will help in understanding the chemical and material factors that are most important for optimizing new materials for ammonia production from dinitrogen, and applications to other important industrial reactions. Involved student researchers will learn a wide range of experimental and computational skills and the PIs will collaborate with other UNT faculty and students to develop brief presentations – in English and Spanish – on important chemistry topics to heighten interest of high school students in pursing Chemistry and other STEM careers.Technical SummaryThe production of NH3 from N2 relies on the high temperature Haber-Bosch process which consumes much energy and produces significant CO2 and the design of new materials to provide an environmentally/energetically friendly alternative to produce N2 can have significant impact on agriculture, energy saving, and the environment. Earth-abundant transition metal oxides and oxynitrides are rapidly growing in interest for energy and environmental applications, but the fundamental roles of N, O and metal centers in N2 reduction are, however, not well understood. This project, supported by the Solid State and Materials Chemistry and Ceramics programs in the Division of Materials Research, will investigate fundamental interactions at the electrolyte/solid interface relevant to the reduction of dinitrogen to ammonia, and to other electrocatalytic processes, such as the formation of hydrogen and oxygen. Electrochemical methods, combined with in situ and operando surface science probes, will probe the fundamental interactions at the electrolyte/oxynitride interface governing both catalytic efficiency and selectivity. Experimental studies will be both supported and guided by theoretical efforts focused on the energetics of reaction pathways at N-supported vs. O-supported metal centers. Students involved will learn both experimental and theoretical methods, which will enhance their capabilities in both academic and industrial research environments.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.