Probing the Interfacial behavior of nanostructured electrocatalysts for environmentally relevant catalytic systems

重要的可再生能源技术的发展和可行性与其相关催化材料的电化学性能密不可分。电催化剂表面的组成及其原子结构对其性能特征，即其催化活性和反应选择性具有至关重要的影响。对催化过程的基本理解对于社会来说就像寻找电化学装置作为替代能源系统商业化所需的新材料一样有意义。在这两种情况下，电化学继续发挥关键作用。 在电活性材料上研究的各种催化过程中，二氧化碳还原反应（CRR）是与环境应用相关的过程，并且可以用作测试新电极的模型系统的优秀候选者。拟议的研究计划的重点是启动这些氧化还原过程的动力学和机制的研究在纳米结构的合金，改性表面和明确的表面，用于阐明和理解的界面和电化学现象参与电催化过程（吸附现象，电沉积和成核）。我们提出选择性地修饰表面态来研究其对反应中间体和产物性质的影响。 通过对电催化剂中参与金属的性质和化学计量的适当选择，可以设计具有不同吸附能力、流动性和结构几何形状的基底，以抑制或控制副反应并提高过程效率。 该研究计划的重点是“整体效应”的作用和界面金属-电解质的性质，即CRR和ORR，两个相关的电化学反应。新的CO2转化系统将探索与溶剂，如室温离子液体以及与传统的水介质。 为了了解表面修饰和表面结构对有机分子的电化学活性和选择性的影响，将使用在线电化学质谱和旋转环盘电极作为补充技术来研究反应机理和产物。原位X射线吸收光谱也将被探索作为一个强大的技术来研究所设计的电催化剂的表面。从技术上讲，这项研究的目的是提供结果，将在短期或长期内，导致对活性材料的双功能性有更好的基本理解，并最终导致改进的电催化剂用于能量转换和环境应用。

Development and viability of important renewable energy technologies are inextricably linked to the electrochemical performance of their related catalytical materials. The composition of an electrocatalyst's surface and its atomic structure have a crucial influence on its performance characteristics, i.e. its catalytic activity and reaction selectivity. The fundamental understanding of catalytic processes is as meaningful for society as the search for new materials necessary for the commercialization of electrochemical device as alternative energy systems. In both cases, electrochemistry continues to play a pivotal role. Of various catalytic processes examined on electroactive materials, carbon dioxide reduction reaction (CRR) is a relevant processes with environmental applications and can be excellent candidate to be used as model systems for testing new electrodes. The proposed research program is focus on initiating a study of the kinetics and mechanism of those redox processes at nanostructured alloys, modified surfaces and well-defined surfaces for the elucidation and the understanding of the interfacial and electrochemical phenomena involved in electrocatalytic processes (adsorption phenomena, electrodeposition and nucleation). We proposed to modify the surface state selectively to study its role in the nature of the reaction intermediates and products. By the proper choice of the nature and stoechiometry of the participant metal in the electrocatalysts, it is possible to design substrate with various adsorption capability, mobility and structural geometry to inhibit or control the side reactions and to enhance the process efficiency. The research program is focusing on the role of the “ensemble-effect” and the nature of the interface metal-electrolyte, namely for CRR and ORR, two relevant electrochemical reactions. New CO2 conversion systems will be explore with solvents such as room temperature ionic liquids as well as with conventional aqueous media. In order to understand the impact of surface modifications and surface structure on the electrochemical activity and selectivity of (in)organic molecules, the reaction mechanisms and products will be investigate using on-line Electrochemical Mass Spectrometry and Rotating ring-disk Electrodes as complementary techniques. In-situ X-ray Absorption Spectroscopy will also be explore as a powerful technique to study surfaces of the designed electrocatalysts . Technologically, this research aims to provide results that will, on the short or long term, leads towards a better fundamental understanding of bifunctionnality of active materials and, ultimately, should lead to improved electrocatalysts for energy conversion and environmental applications.