Electrochemical catalyst-support interactions (CSI) of oxide-supported oxygen evolution reaction (OER) catalysts and their impact on catalyst activity and corrosion stability

负载在导电高表面积载体材料上的电催化剂构成电化学原电池和电解电池装置（例如电解槽或氢燃料电池）的重要电极组分。这种催化剂/载体对的反应性和稳定性决定了重要的整体性能指标，例如电池效率和耐久性。由于在它们的界面处的直接化学相互作用，催化剂和载体可以影响彼此的化学反应性，这在气-固催化中是众所周知的，并且在那里，通常被称为催化剂-载体相互作用（CSI），或者更具体地，被称为“强金属-载体相互作用（smsi）”。 然而，CSI在电化学固液界面处的概念在很大程度上仍未得到解决，但由于其增强电催化剂的催化活性和电化学稳定性的潜力而引起了最近的兴趣。该项目旨在解决固液界面电化学CSI的基本科学问题，并探索在真实的电催化剂/支持对中利用CSI的可能性。其主要目标是探索，证实和量化的化学性质，机制的起源和可测量的影响CSI的反应性和稳定性的氧化物支持的Ir基析氧（OER）电催化剂。我们的工作假设是，CSI可以定制和利用，以减轻催化剂的腐蚀和电解槽运行过程中的降解。使用定义明确，光滑的催化剂/载体模型，我们将探索和比较选定的一些不同的导电氧化物载体材料，并研究它们对电子和几何结构的影响，以及表面氧化还原化学和催化OER性能的Ir-氧化物催化剂，特别强调催化剂/载体的稳定性。各种各样的非原位和操作表征技术，包括XAS，XPS，ICP-MS，DEMS，明确的表面和纳米结构将在这个项目的过程中使用。电化学CSI的洞察力将转移到纳米结构的Ir基催化剂/支持对催化OER条件下运行。项目团队由三个学术小组组成，他们在电催化，腐蚀科学和表面纳米催化与操作光谱学的结合方面具有丰富的专业知识。作为一个主要的成果，这个项目将建立一个更深入的理解CSI效应在OER和它的见解将有助于包括CSI效应在水裂解电催化剂的合理设计。

Electrocatalysts supported on conductive high surface-area carrier materials constitute an important electrode component of electrochemical galvanic and electrolytic cell devices, such as electrolyzers or hydrogen fuel cells. The reactivity and stability of such catalyst/support couples determine the important overall performance metrics, such as cell efficiency and durability. Owing to a direct chemical interaction at their interface, catalyst and support may influence each other’s chemical reactivity, something well known in gas-solid catalysis and, there, commonly referred to as catalyst-support interaction (CSI) or more specifically, as „strong metal-support interactions (smsi)“. The concept of CSI at electrochemical solid-liquid interfaces, however, has largely remained unaddressed, yet is attracting much recent interest due to its potential to enhance both catalytic activity and electrochemical stability of electrocatalysts. This project is designed to address fundamental scientific aspects of electrochemical CSIs at solid-liquid interfaces and explore the possibility to leverage CSIs in real electrocatalyst/support couples. Its major objective is to explore, substantiate, and quantify the chemical nature, the mechanistic origin and measurable impact of CSIs on reactivity and stability in oxide-supported Ir-based oxygen evolution (OER) electrocatalysts. Our working hypothesis is that CSIs can be tailored and leveraged to mitigate catalyst corrosion and degradation during electrolyzer operation. Using well-defined, smooth catalyst/support models, we will explore and compare a selected number of different conductive oxidic support materials and study their impact on the electronic and geometric structure as well as surface redox chemistry and catalytic OER performance of Ir-oxide catalysts with special emphasis on catalyst/support stability. A wide variety of ex-situ and operando characterization techniques, including XAS, XPS, ICP-MS, DEMS, of well-defined surfaces and nanostructures will be employed in the course of this project. Insight in electrochemical CSIs will be transferred to nanostructured Ir based catalyst/support couples operating under catalytic OER conditions. The project team comprises three academic groups with much expertise in electrocatalysis, corrosion science and surface nanocatalysis in combination with operando spectroscopy. As a major outcome, this project will establish a deeper understanding of CSI effect in OER and its insights will aid to include CSI effect in the rational design of water splitting electrocatalysts.