Elucidating the role of catalyst-support interaction on the activity and stability of water splitting catalysts

该提案探讨了催化剂和固体载体在带电固液界面处的化学相互作用的性质和影响。催化剂|本文所述载体体系包含非贵金属催化剂作为析氢反应（HER）和析氧反应（OER）的活性位点。该项目将使用与光电化学器件相关的选定载体系统地研究催化剂-载体相互作用，并建立掩埋的催化剂-载体界面的几何和电子结构与其在电极-电解质界面处产生的光电化学活性和稳定性之间的关系。一个主要的焦点是理解不同类型的催化剂的电子和结构相互作用的程度|从根本上支持系统。例如，吸附相互作用与共价连接的活性位点相互作用（通过不同的连接基团）将允许关于在多大程度上确实需要官能化和连接的附加步骤以获得活性和稳定的催化剂的结论|作为OER的催化剂，NiFe基氧化物和（氧）氢氧化物（NiFeOx）以及具有分子MeN 4中心的HER催化剂被研究。基于标准的结构和电化学表征，将选择不同的系统进行更详细的表征。作为先进的表征技术，不同的方法被应用于现场和操作，如X射线吸收光谱（XAS）和穆斯堡尔光谱。结合所选样品的（环境压力）X射线光电子能谱（XPS），对不同气体气氛和电解质存在下的界面进行逐步分析，将能够得出催化剂的电子和结构相互作用程度的结论。|支持系统发生了变化。虽然主要焦点集中在催化剂上|支持模型电极上的相互作用，真实的设备中的相互依赖性也将得到解决。因此，最有前途的催化剂体系将在相关的半导体（SC）或SC +钝化层上进行研究。因此，与具有一个固-固界面的模型电极相比，这些器件联合收割机所有的界面和相关的相互依赖性，因此，所获得的结果应该能够为后续项目中需要集成到器件中的这种功能复合结构的基于知识的设计的未来工作进行有用的预测。虽然该项目侧重于基本方面（但与相关支持物密切相关），但在未来的工作中，还将进一步优化催化剂或应用新的催化系统。该项目中获得的结果可能对其他催化系统或结构也很重要，这些系统或结构使用强电子耦合来协调功能单元。

This proposal explores the nature and impact of chemical interactions between a catalyst and a solid support at electrified solid-liquid interfaces. Catalyst|support systems addressed here comprise non-precious metal catalysts as active sites for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The project will systematically study catalyst-support interactions using selected supports relevant to photoelectrochemical devices and establish relations between the geometric and electronic structure of the buried catalyst-support interface and its resulting photoelectrochemical activity and stability at the electrode-electrolyte interface.In order to reach this goal, a main focus is directed to understand the extent of electronic and structural interaction for different types of catalyst|support systems on a fundamental level. For instance, adsorptive interaction versus covalently attached active site interaction (via different linkage groups) will allow conclusions as to what extent the additional steps of functionalization and linkage are indeed required to obtain an active and stable catalyst|support system.As catalysts NiFe-based oxides and (oxy)hydroxides (NiFeOx) are investigated for the OER and catalysts with molecular MeN4 centers for the HER. Based on standard structural and electrochemical characterization different systems will be selected for a more detailed characterization.As advanced characterization techniques different methods are applied in-situ and operando as X-ray absorption spectroscopy (XAS) and Mössbauer spectroscopy. The stepwise analysis of the interface with respect to the presence of different gas atmospheres and electrolytes in combination with (ambient pressure) X-ray photoelectron spectroscopy (XPS) of selected samples will enable conclusions to what extent the electronic and structural interaction of the catalyst|support system are changed.While the main focus is directed on the catalyst|support interaction on model electrodes, the interdependence in real devices will be addressed as well. Therefore, the most promising catalyst systems will be investigated on the related semiconductors (SC) or SC + passivation layer. Thus, in contrast to the model electrode with one solid-solid interface, these devices combine all the interfaces and related interdependence.As a consequence, the acquired results should enable useful predictions for future works on a knowledge-based design of such functional composite structures that need to be integrated in devices within the follow-up project. While this project focusses on the fundamental aspects (but in close relation to relevant supports), in future work also the further optimization of catalysts or application of new catalytic systems will be addressed.The results obtained in this project might be of importance also for other catalytic systems or structures that uses strong electronic coupling for coordination of functional units.