Spectroelectrochemical characterization of heterogeneous electrocatalyst surfaces

二氧化碳的电催化还原是一种引起了几代科学家兴趣的反应，目前在工业界、政府和学术界引起了极大的关注。现在人们对电化学还原二氧化碳的兴趣很大程度上源于这样一个事实：当与水氧化相结合时，这种反应提供了一种产生可持续的全球碳循环的可行方法。这种循环将减轻人为二氧化碳排放的影响，同时为合成有用的化学品（从碳氢化合物燃料到商品化学品）提供非化石燃料原料。然而，尽管经过几十年的研究，具有有限商业/工业兴趣的2电子还原产物仍然是唯一能够以可接受的选择性可靠地合成的产品。拟议的研究计划旨在建立一个长期的战略重点，将利用最先进的光谱电化学技术进行机制研究，以实现催化剂的合理设计，能够选择性地将二氧化碳转化为高价值的商业相关化学品。

The electrocatalytic reduction of CO2 is a reaction that has captured the interest of generations of scientists and currently commands significant attention in industrial, government and academic circles. Much of the modern interest in electrochemical reduction of CO2 originates from the fact that, when coupled with water oxidation, this reaction provides a viable means to generate a sustainable, global carbon cycle. Such a cycle would act to mitigate the impact of anthropogenic CO2 emissions while providing a non-fossil fuel feedstock for synthesizing useful chemicals, ranging from hydrocarbon fuels to commodity chemicals. Despite decades of research, however, 2-electron reduction products with limited commercial/industrial interest remain the only products that can be reliably synthesized with acceptable selectivity. The proposed research program seeks to establish a long-term, strategic focus that will utilize state-of-the-art spectroelectrochemical techniques to perform mechanistic studies to enable the rational design of catalysts capable of selective conversion of CO2 into high value, commercially relevant chemicals. Numerous reports have described changes to the electrochemical reaction system that enable conversion of CO2 into mixtures of desirable hydrocarbon products. Strategies that have enabled hydrocarbon synthesis include electrode composition turning, electrode surface engineering, and addition of co-catalysts to the electrolyte solution. These approaches tend to produce a diverse mixture of chemical products, however, and the ability to selectively synthesize desirable products remains elusive. This research program will capitalize on recent advances in spectroscopic instrumentation and techniques to acquire structural information on heterogeneous electrocatalyst surfaces under operational conditions (i.e. in-situ spectroelectrochemistry). Spectroelectrochemical measurements performed during operation will enable changes in chemistry at/near the electrode surface to be monitored, yielding information regarding reaction mechanisms. Repetition of the experiments upon strategic, systematic variation of components in the overall system, upon addition of a series of co-catalysts for example, will reveal the impact of the reaction component on the reaction mechanism. The library of data that will be generated throughout this research program will be comparatively analyzed to reveal design principles enabling the rational design of electrocatalysts and reaction system modifications to improve the selectivity of electrocatalytic CO2 reduction.