NanoFunC - Controlling Selectivity via Nanostructuring of Multifunctional Model Catalysts

未来的愿景是合理设计具有改进的选择性和活性的纳米结构催化剂材料。为了实现这一目标，我们探索的潜力，在CO2重整和CO2-OCM（氧化偶联）的甲烷的基础模型研究。受涉及多功能材料的经验方法的启发，开发了新颖的多重纳米结构模型催化剂，其在明确限定的环境中整合了例如（a）氧化还原位点（例如CeO 2）（B）碱性中心（例如MgO、BaO），（c）金属位点（例如Rh、Pt）和（d）载体位点（例如Al 2 O 3）。该项目的三步战略基于一系列独特的实验技术：（i）在超高真空条件下制备多纳米结构模型表面，并研究其结构和化学性质（颗粒结构、尺寸、密度、缺陷、边界位置、复合/孤立纳米颗粒等）。使用超高真空显微镜和广泛的表面科学方法进行详细表征。(ii)的结构特性与基本反应动力学，能量学和动力学的选定的关键步骤在微观层面上，应用MB（分子束）技术和时间分辨表面光谱。(iii)最后，纳米结构和基本动力学的信息相结合，系统和定量动力学研究，应用多MB方法，反应器方法，和时间分辨的原位表面光谱从超高真空环境条件（“压力间隙”）。在这三个步骤中，实验研究都与高水平的密度泛函理论（DFT）计算紧密相连，该计算采用了最近开发的先进的纳米结构反应系统的现实模型，从而可以充分描述后者。该项目的目的是开发微观上有充分依据的机理模型，从而提供完整反应系统的一致描述。这些模型将明确纳入动力学控制的纳米结构和相互作用的动力学效应在multiply纳米结构系统。关于CO2重整和CO2-OCM，通过纳米结构化优化选择性是主要关注的，包括例如通过动力学抑制碳形成来控制失活的方面。除了对这些特定目标反应的重大贡献外，该项目还将产生概念性的见解，指导未来的设计策略，以定制纳米结构催化剂。

A future vision is the rational design of nanostructured catalyst materials with improved selectivity and activity. Towards this aim we explore the potential of fundamental model studies in CO2-reforming and CO2-OCM (oxidative coupling) of methane. Inspired by empirical approaches involving multifunctional materials, novel multiply nanostructured model catalysts are developed, which integrate, for instance (a) redox sites (e.g. CeO2) (b) basic centres (e.g. MgO, BaO), (c) metallic sites (e.g. Rh, Pt) and (d) support sites (e.g. Al2O3) in a well-defined environment. The three-step strategy of this project is based on a unique portfolio of experimental techniques: (i) Multiply nanostructured model surfaces are prepared under UHV (ultrahigh vacuum) conditions and their structural and chemical properties (particle structure, size, density, defects, boundary sites, composite/isolated nanoparticles, etc.) are characterized in detail using UHV microscopies and a broad spectrum of surface science methods. (ii) The structural properties are correlated with elementary reaction kinetics, energetics and dynamics of selected key steps at the microscopic level, applying MB (molecular beam) techniques and time-resolved surface spectroscopies. (iii) Finally, the information on nanostructure and elementary kinetics is combined with systematic and quantitative kinetic studies, applying multi MB methods, reactor methods, and time-resolved in-situ surface-spectroscopies from UHV to ambient conditions (“pressure gap”). In all three steps, the experimental studies are closely linked with high-level DFT (density functional theory) calculations employing advanced recently developed realistic models of nanostructured reaction systems, which allow for adequate description of the latter.The aim of the project is to develop microscopically well-founded mechanistic models, which provide a consistent description of the complete reaction system. These models will explicitly incorporate kinetic control by nanostructuring and the mutual interplay of kinetic effects in multiply nanostructured systems. With respect to CO2-reforming and CO2-OCM the optimization of selectivity by nanostructuring is of primary interest, including aspects such as e.g. controlling deactivation by kinetically suppressing carbon formation. Beyond strong contribution to these specific target reactions, the project will result in conceptual insights guiding future design strategies towards tailor-made nanostructured catalysts.