Interparticle Metal-Metal Interactions in Electrocatalytic Carbon Dioxide Reduction Reactions

向清洁能源过渡的一大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，是将碳排放转化为资源的一种有希望的方式。钯是一种独特的金属，可以催化二氧化碳电化学转化为甲酸根离子(HCOO-)。甲酸盐是一种积木化合物，可用于生产甲醛和甲醇等工业重要化学品。然而，钯的催化性能受到催化剂活性中心快速失活的严重限制，如果不进一步了解反应和失活机理，很难设计出改进的体系。本研究项目将研究由钯和一种二次金属组成的新型催化剂。其目的是稳定催化剂的活性中心，从而开发出能够持续、高效地将二氧化碳转化为甲酸盐的催化剂。这项研究项目还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调查纳米级颗粒间金属-金属相互作用如何影响二氧化碳在钯上电还原的催化机理。目标是限制甲酸盐生产过程中催化剂的失活，并使甲醛或甲醇等新产品的合成成为可能。金属纳米粒子将被用作“电子配体”，并修饰钯与反应中间体的结合强度。纳米粒子还可以作为“协作性配体”，通过提供第二种类型的表面位置直接参与催化。将研究钯与各种其他金属之间的电子和协同作用。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和依赖于电位的还原反应途径的结合能。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。

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.