Imidazolium Functionalized Transition Metal Phosphide Catalysts for Electrochemical Carbon dioxide Conversion to Ethanol

电化学反应是将废弃的温室气体二氧化碳（CO2）转化为有价值的化工产品的一种很有前途的技术。 当由风能或太阳能等可持续电力提供动力时，电化学CO2还原反应（eCO 2 RR）技术可能为化学制造提供负碳排放途径。 然而，目前的eCO 2 RR技术受限于依赖昂贵的贵金属催化剂材料、电催化反应中的能量损失、CO2向目标产物的低效转化以及CO2捕获和转移到工作催化剂表面的低速率。 该项目通过旨在开发一种有效催化系统的研究来解决这些技术差距，该系统基于用化学化合物（咪唑（Im））改性的低成本过渡金属磷化物（TMP）类材料，该化合物可增强CO2向催化剂表面的转移。 这两个组成部分共同促进了废物CO2的捕获和转化为乙醇，用于下游燃料和化学应用。 除了技术方面，该项目还支持教育和研究计划，教育未来的清洁能源和可持续发展技术领导者。 该项目是建立在咪唑功能化TMP催化剂可以定制表面金属原子的电子性质，以促进碳-碳耦合的高速率乙醇生产的假设。该项目采用系统的方法，结合实验和计算研究，设计和验证Im-TMP催化系统的不同组分，并确定在拟议催化系统的活性，选择性和稳定性中起关键作用的关键因素。该项目利用现有的合作关系，旨在通过电化学测试和分析的直接实验努力，建立一种新型的催化系统，用于从CO2电合成乙醇。各种纳米结构的TMP纳米粒子，与MP（M：过渡金属）的化学计量和他们的IM功能化的结构，将进行表征和评估。 材料组合的选择是基于研究人员研究的初步结果，表明咪唑功能化磷化钼（Im-MoP）纳米颗粒作为一个统一的系统来生产乙醇。该项目目标的关键是将尖端的原位，非原位，原子和分子尺度实验与DFT计算相结合，以确定TMP表面原子的电子和结构特性及其与咪唑的相互作用。这些信息将用于开发Im-TMP催化剂的电子-结构-性能关系。 从研究中获得的见解将为开发用于其他常见电催化过程的先进材料建立新的方法，例如固氮，氧还原和析氧反应，其中用有机分子功能化催化剂表面可能会显示出类似的好处。从教育和推广的角度来看，该项目将与研究人员校园内的本科研究教育联合计划（PURE）对接。 此外，研究人员将与伊丽莎白城州立大学，HBCU和公立学士学位机构合作，为各种电化学应用带来与材料设计，合成和表征相关的知识，并为来自代表性不足的群体的学生提供研究机会，鼓励他们攻读能源科学的高级学位。该项目还将通过沉浸式的夏季研究体验，为来自区域芝加哥学校的代表性不足的高中生群体提供实践研究机会。该奖项反映了NSF的法定使命，并被认为值得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来支持。

Electrochemical reaction is a promising technology for converting the waste greenhouse gas, carbon dioxide (CO2), to valuable chemical products. When powered by sustainable electricity from sources such as wind power or solar energy, electrochemical CO2 reduction reaction (eCO2RR) technology potentially offers a negative carbon emission route to chemical manufacturing. Current eCO2RR technology is limited, however, by dependence on expensive noble metal catalyst materials, energy losses in the electrocatalytic reactions, inefficient conversion of CO2 to targeted products, and low rates of CO2 capture and transfer to the working catalyst surface. The project addresses those technology gaps through research aimed at developing an effective catalytic system based on a low-cost transition metal phosphide (TMPs) class of materials modified with a chemical compound (imidazolium (Im)) that enhances the transfer of CO2 to the catalyst surface. Together the two components promote the capture and conversion of waste CO2 to ethanol for use in downstream fuel and chemical applications. Beyond the technical aspects, the project supports educational and research programs educating future leaders in technology related to clean energy and sustainability. The project is built on the hypothesis that imidazolium-functionalized TMP catalysts can tailor the electronic properties of surface metal atoms to promote carbon-carbon coupling for high rate ethanol production. The project employs a systematic approach, combining experimental and computational studies to design and validate different components of the Im-TMP catalytic system, and to identify key factors that play crucial roles in activity, selectivity, and stability of the proposed catalytic system. The project exploits existing collaborative relationships with the aim of establishing a novel catalytic system for electrosynthesis of ethanol from CO2 through directed experimental efforts in electrochemical testing and analysis. Various nanostructured TMP nanoparticles, with stoichiometry of MP (M: transition metal)and their Im-functionalized structure, will be characterized and evaluated. The materials combinations are selected based on preliminary results from the investigators’ research showing that imidazolium-functionalized molybdenum phosphide (Im-MoP) nanoparticles work as a unified system to produce ethanol. Crucial to the goal of this project, is the combination of cutting edge in-situ, ex-situ, atomic- and molecular-scale experiments with DFT calculations that will be performed to identify electronic and structural properties of TMP surface atoms and their interactions with imidazolium. This information will be utilized to develop electronic–structural–performance relationships of the Im-TMP catalysts. The insights gained from the research will establish new methods for the development of advanced materials for other common electrocatalytic processes, such as nitrogen fixation, and the oxygen reduction and oxygen evolution reactions, where functionalizing the surface of catalysts with organic molecules may show similar benefits. From the educational and outreach perspectives, the project will interface with the joint initiatives Program for Undergraduate Research Education (PURE) on the investigators’ campus. Additionally, the investigators will collaborate with Elizabeth City State University, a HBCU and public baccalaureate institution, to bring knowledge related to materials design, synthesis, and characterization for various electrochemical applications and provide research opportunities for students coming from under-represented groups, encouraging them to pursue advanced degrees in energy sciences. The project will also provide hands-on research opportunities to underrepresented groups of high-school students from regional Chicago schools through an immersive summer research experience.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.