Project Details
Projekt
Enhancing Gas-Phase Generation of Electrocatalytic Hetero-Aggregates via Advanced Diagnostics and Performance Evaluation
Applicants
Dr. Torsten Endres; Professor Dr. Hartmut Wiggers
Subject Area
Mechanical Process Engineering
Term
since 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 462473659
Controlling and mastering material structures at the nano and micro scales remains a formidable yet imperative challenge. Especially targeting production pathways that enable the direct formation of hetero-aggregates in potentially scalable continuous gas-phase reactions is an important topic. To this end, in situ optical diagnostics techniques provide the understanding of underlying processes that then enables process design and improvement. Different aspects of heterogeneous powder mixtures investigated in the first funding period in the individual projects of Endres and Wiggers within the framework of the SPP are now combined in a joint project proposal with the objective to be able to build a bridge from the hetero-aggregate formation of two materials in the gas phase to the function of the resulting composite. This joint application therefore combines the possibilities of optical in situ measurement techniques for investigating heteroaggregate formation with process design and control, spatially resolved sampling technology and investigations into the functionality of the hetero-aggregates formed. The focus is the hetero-aggregate formation of an electrically conductive material (few-layer graphene, FLG, produced from our own gas phase synthesis) with an electrocatalytically active material. In continuation of the work of the first application phase, self-produced TiO2 is chosen here as an example. Therefore, the central aim is to clarify, on the basis of experimental investi-gations with a view to electrocatalytic performance, to which extent the hetero-aggregation of an electron conductor with a catalyst can be achieved through aerosol interaction and how this aggregation influences the electrocatalytic properties of the composite material. The focus is on the following questions: 1) How is it possible to achieve an intimate mixture of aerosols containing the two components of the hetero-aggregate? To this end, the extent to which mixing and subsequent hetero-aggregation can be achieved despite the presence of larger fractal aggregates of both starting materials and thus limited diffusion will be investigated. 2) To which extent do temperature and residence time during mixing in the aerosol phase influence hetero-aggregation, and how does this affect the electrochemical performance of the resulting composites? 3) To which extent is the laser-generated signal indicating the formation of hetero-aggregates in the aerosol phase indicative for the performance of the resulting material? 4) Derived from this, the question will be answered how – with regard to the functionality of the composite - the hetero-aggregation process in the gas phase must be designed and what is a suitable/necessary mixing ratio of the two components. As the joint experimental platform, we will use mixing aerosol streams from two independent reactors (Reactor Mixing System, RMS, operated by the Wiggers group) and apply a novel Matrix Mixing System (MMS, Endres group).
DFG Programme
Priority Programmes
Co-Investigator
Professor Dr. Christof Schulz
