Speaker
Description
Oxides represent an important class of materials in catalysis. They serve as active components or control the catalytic properties of an active phase via the interaction between the two phases at a functional interface. The research objective of the working group "Catalysis with Oxides" is to investigate the influence of synthesis on the structural and electronic properties of an oxide precursor and the resulting formation of the active state of a catalyst under the conditions of oxidation of short-chain alkanes, ammonia decomposition and hydrogenation of CO, CO$_{2}$ and of unsaturated hydrocarbons.
The partial oxidation of hydrocarbons provides access to many valuable chemical intermediates, especially for further processing in polymerisation reactions. However, the oxidation of organic molecules is always governed by a complex reaction network, and the particular difficulty is to optimise the process conditions and the catalysts so that only one desired compound is selectively formed and the thermodynamically preferred total oxidation to unwanted CO$_{2}$ is avoided. We have investigated the influence of structural reconstructions on the selectivity in propane oxidation and compared perovskites that remain unchanged in their phase composition with catalysts where significant phase transformations occur under reaction conditions due to melting processes. We found that the thermodynamically limited activation of di-oxygen to electrophilic oxygen species and the fast sorption-desorption kinetics over more inert fillers, such as SiO$_{2}$, are success factors for the formation of products prone to overoxidation, such as propylene oxide. The results are presented in poster AC 1.1.
In a recently initiated project, we are working on the synthesis of oxides as precursors of catalysts for ammonia decomposition. In this context, we are systematically investigating a matrix of host structures containing the metals Ni, Co and Fe, prepared by precipitation, supercritical hydrothermal synthesis and flame spray pyrolysis, which can be structurally divided into solid solutions with rock salt structure, spinels and perovskites. For the first results see poster AC 1.2.
A similar approach is taken in the synthesis of catalysts for the direct hydrogenation of CO and CO$_{2}$ to olefins or ethanol. Unlike supported catalysts, we create a functional interface between the exfoliated active metal and one or more promoters by decomposing the host structure during the catalyst formation phase. The results are summarised in poster AC 1.3.
The group coordinates the activities of the AC department to build a local data infrastructure necessary for the transformation to Digital Catalysis. On the one hand, the technical infrastructure, such as electronic laboratory notebooks and automated data generation and storage, is being implemented in cooperation with the Computer Support Group of the FHI and within the framework of the NFDI project FAIRmat. On the other hand, this infrastructure is used in pilot projects on propane dehydrogenation and acetylene hydrogenation in the BasCat and CatLab projects to gain a deeper understanding of the interaction between an active phase and a support at functional interfaces through data-driven approaches and the application of artificial intelligence methods in close cooperation with the Theory Department. An overview is given in poster AC 6.1.
| Abstract Number (department-wise) | AC 1.0 |
|---|---|
| Department | AC (Schlögl) |
