Oberflächendynamik von inverser Ni- und Cu- Katalysatoren: Neue Konzepte für die CO2-Hydrierung durch Promotierung mit reduzierbaren Oxiden

氧化物对金属加氢催化剂的促进作用在CO2的活化和转化中起着重要作用。从工业应用的铜/氧化锌催化剂出发，这一方法将在本项目中进行概念性扩展，以从根本上更好地了解它，充分挖掘其潜力。在这里，重点是“反”金属氧化物/过渡金属催化剂在二氧化碳加氢条件下的表面动力学。所研究的催化剂的逆特性为研究可还原金属氧化物与过渡金属表面之间的动态相互作用提供了新的见解。这是通过使用氧化还原惰性载体来稳定过渡金属颗粒并在其表面沉积金属氧化物成分来实现的。这种方法已经在SPP2080的第一个资助期成功地使用了氧化镁负载的氧化锌/铜催化剂进行了测试。该项目的目的是加深这方面的知识，并将其作为一种新的过渡金属镍和作为一种新的可还原氧化物的氧化镓转移到镍上。这将导致四种金属氧化物/过渡金属(MO/TM)催化剂的组合：锌氧化物/铜、氧化镓/铜、氧化锌/镍和氧化镓/镍。重要的是，这四个系统都可以在还原条件下形成合金或金属间化合物，但在合金/金属间化合物的形成热和金属氧化物的可还原性方面有所不同，从而为系统地研究和推广我们在第一个资助期获得的关于ZnOx/Cu系统的结果提供了合适的材料基础。在SPP2080的第一个资助期，详细研究了氧化锌/铜体系表面合金的形成程度。通过在氧化镁载体上定向合成氧化锌/铜催化剂、X-射线能谱分析和理论模拟，阐明了相关的动力学过程。现在，向新材料的转移使人们能够深入和全面地了解这些反金属氧化物/过渡金属催化剂的动力学和相关的催化行为，以便专门利用这些界面现象来提高二氧化碳加氢的活性和选择性。这将有助于全面了解此类MO/TM催化剂的动力学，并通过反应条件控制其表面结构。这些发现将应用于工业上重要的甲醇合成以及一般动态条件下的二氧化碳加氢反应。

The promotion of metallic hydrogenation catalysts by oxides plays a major role in the activation and conversion of CO2. Starting from the industrially applied Cu/ZnO catalyst, this approach will be conceptually extended in this project to fundamentally better understand it and to fully exploit its potential. Here, the focus is on the surface dynamics of "inverse" metal oxide/transition metal catalysts under CO2 hydrogenation conditions. The inverse character of the catalysts studied provides new insights into the dynamic interplay between reducible metal oxides and the surface of transition metals. This is achieved by using a redox-inert support to stabilize the transition metal particles and depositing the metal oxide component on their surface. This approach has already been successfully tested in the first funding period of SPP2080 using MgO-supported ZnOx/Cu catalysts. The aim of this project is to deepen this knowledge and to transfer it to Ni as a new transition metal and Ga2O3 as a new reducible oxide. This will result in the combinations of the four metal oxide/transition metal (MO/TM) catalysts ZnOx/Cu, GaOx/Cu, ZnOx/Ni and GaOx/Ni. Importantly, all four systems can form alloys or intermetallic compounds under reducing conditions, but differ in the heat of formation of the alloy/intermetallic compound and the reducibility of the metal oxide, thus providing a suitable material base to systematically investigate and generalize our findings on the ZnOx/Cu system obtained in the first funding period. In the first funding period of SPP2080, the ZnOx/Cu system was investigated in detail to what extent surface alloys are formed. The associated dynamics were elucidated by targeted synthesis of ZnOx/Cu catalysts on MgO supports, operando X-ray spectroscopy, and theoretical modeling. The transfer to new materials now enables the vision of developing a deep and comprehensive understanding of the dynamics and associated catalytic behavior of these inverse metal oxide/transition metal catalysts in order to specifically exploit these interfacial phenomena to improve activity and selectivity in the hydrogenation of CO2. This will contribute to the general understanding of the dynamics of such MO/TM catalysts and control their surface structure by reaction conditions. These findings will be applied to the industrially important methanol synthesis as well as to CO2 hydrogenation reactions in general under dynamic conditions.