Interparticle Metal-Metal Interactions in Electrocatalytic Carbon Dioxide Reduction Reactions

向清洁能源过渡的一个主要挑战是减少燃料燃烧产生的二氧化碳排放。利用可再生电力将二氧化碳转化为增值燃料和化学产品是一种很有前途的将碳排放转化为资源的方法。钯是一种独特的金属，可以催化二氧化碳的电化学转化为甲酸离子（HCOO-）。甲酸盐是一种基本化合物，可用于生产工业上重要的化学品，如甲醛和甲醇。然而，钯的催化性能受到催化剂活性位点快速失活的严重限制，如果不进一步了解反应和失活机制，就很难设计改进的体系。本研究项目将研究钯和一种次级金属组成的新型催化剂。目的是稳定催化剂的活性位点，从而开发出能够持续、有效地将二氧化碳转化为甲酸盐的催化剂。这个研究项目也将为大量不同的学生提供新的教学和学习机会。本研究项目的目的是研究纳米级颗粒间金属-金属相互作用如何影响二氧化碳电还原钯的催化机制。目标是在甲酸酯生产过程中限制催化剂失活，并使新产品如甲醛或甲醇的合成成为可能。金属纳米粒子将被用作“电子配体”，并改变钯与反应中间体的结合强度。纳米颗粒还可以作为“协同配体”，通过提供二级表面位点直接参与催化。钯和其他多种金属之间的电子和协同相互作用将被研究。此外，还将进行实验，以了解这些相互作用如何改变钯与反应中间体的结合能和电位依赖的还原反应途径。最终，从这些研究中获得的知识将用于开发稳定的电催化剂，以有效地将二氧化碳转化为甲酸盐，然后再转化为更复杂的产品。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。

A major challenge in the transition to clean energy is reducing emissions of carbon dioxide from fuel combustion. Using renewable electricity to convert carbon dioxide to value-added fuels and chemical products is a promising way of turning carbon emissions into a resource. Palladium is a unique metal that can catalyze the electrochemical conversion of carbon dioxide to formate ion (HCOO-). Formate is a building-block compound that can be used to produce industrially important chemicals such as formaldehyde and methanol. The catalytic performance of palladium, however, is severely limited by rapid deactivation of the catalyst active site, and it is difficult to design improved systems without further understanding of both the reaction and deactivation mechanisms. This research project will study novel catalysts composed of palladium and a secondary metal. The aim is to stabilize the catalyst active site and thereby develop catalysts can perform the sustained, efficient conversion of carbon dioxide into formate. This research project also will foster new teaching and learning opportunities for a large and diverse body of students.The aim of this research project is to investigate how nanoscale interparticle metal-metal interactions influence the catalytic mechanisms of carbon dioxide electroreduction on palladium. The goals are to limit catalyst deactivation during the production of formate and to enable the synthesis of new products such as formaldehyde or methanol. Metal nanoparticles will be used as “electronic ligands” and modify the binding strength of palladium with reaction intermediates. The nanoparticles also can act as “collaborative ligands” that directly participate in catalysis by providing a secondary type of surface site. The electronic and collaborative interactions between palladium and a variety of other metals will be studied. Additionally, experiments will be performed to learn how these interactions change the binding energetics of palladium with the reaction intermediates and the potential-dependent reduction reaction pathways. Ultimately, the knowledge gained from these studies will be used to develop electrocatalysts that are stable for efficient conversion of carbon dioxide to formate and then on to more complex products.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.