Collaborative Research: Designing Nitrogen Coordinated Single Atomic Metal Electrocatalysts for Selective CO2 Reduction to CO

化石燃料(即煤炭、石油和天然气)仍然是当今的主要能源，但它们的使用增加了碳排放。能够将废弃的二氧化碳(CO2)转化为增值化学品的技术对于实现可持续能源未来具有重大的经济和社会意义。从阳光产生的电力为二氧化碳转化为化学品提供了一条潜在的可持续途径，但目前的电化学方法需要昂贵的贵金属作为催化剂。该项目将专注于发现贵金属催化剂的高性价比替代品，同时为美国在能源利用方面的研究领先做出贡献。该项目将影响与可再生能源、水使用、交通和国防相关的广泛技术。此外，研究成果将被纳入课程开发、学生指导以及对高中教师和学生的教育推广。该奖项还将扩大未被充分代表的群体参与研究的范围，并将对科学和工程学科的高等教育产生积极影响。氮配位的单原子金属(如铁、钴或镍)是一种新型的电催化剂，在最近的研究中显示出令人印象深刻的活性和相对较高的选择性，用于将二氧化碳电化学还原为一氧化碳(CO)。然而，在这种复杂的催化剂体系中，活性中心的化学性质以及二氧化碳还原的催化机理还没有完全被了解。此外，控制二氧化碳还原选择性的因素与竞争性水还原反应相比还不是很清楚。本研究旨在为合理设计碳骨架中氮配位的单原子金属中心提供基础性的认识，并阐明催化剂的合成、性能和选择性二氧化碳还原为CO的性能之间的关系。研究小组将1)使用第一性原理计算方法预测活性中心，2)合成包含预测的活性中心和局部碳结构的催化剂，3)对合成的催化剂的化学性质、结构和形貌进行综合表征，4)测量合成的催化剂对二氧化碳电化学还原的性能。这项研究将为如何通过调整中心金属氮原子的配位环境和当地的碳结构来实现二氧化碳还原为CO的催化剂的尽可能高的活性和选择性提供见解。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。

Fossil fuels (i.e., coal, petroleum, and natural gas) are still today's primary energy sources, but their utilization increases carbon emissions. Technologies that can convert waste carbon dioxide (CO2) into value-added chemicals have great economic and societal importance for realizing a sustainable energy future. Electricity, generated from sunlight, offers a potential sustainable route for CO2 conversion to chemicals, but present electrochemical approaches require expensive precious metals as catalysts. The project will focus on discovery of cost-effective alternatives to the precious metal catalysts while contributing to U.S. research leadership in energy utilization. The project will impact a broad range of technology related to renewable energy, water usage, transportation, and defense. Moreover, the research results will be incorporated into curriculum development, student mentoring, and educational outreach to high-school teachers and students. This award will also broaden the participation of underrepresented groups in conducting research and will positively impact higher education in science and engineering disciplines.Nitrogen coordinated single atomic metal (e.g. iron, cobalt, or nickel) is a new type of electrocatalyst that has demonstrated impressive activity and relatively high selectivity for electrochemical reduction of CO2 to carbon monoxide (CO) in recent research. However, the chemical nature of the active sites as well as the catalytic mechanisms for CO2 reduction in such complex catalyst systems are not fully understood. In addition, the factors controlling selectivity to CO2 reduction versus the competitive water reduction reaction are not well known. This research aims to provide fundamental understanding of rationally designed nitrogen coordinated single atomic metal sites embedded in a carbon framework and to elucidate the relationship between the synthesis, properties and performance of the catalysts in selective CO2 reduction into CO. The research team will 1) predict the active sites using first-principles calculation methods, 2) synthesize the catalysts containing the predicted active sites and local carbon structures, 3) conduct comprehensive characterization of the chemical properties, structure, and morphology of the synthesized catalysts, and 4) measure the performance of the synthesized catalysts for electrochemical CO2 reduction. This research will provide insights on how to achieve the highest possible activity and selectivity of the catalysts for CO2 reduction to CO through tuning the coordination environment of the central metal-nitrogen atom and the local carbon structure.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.