A tunable fabrication platform towards tailored porous multi-composite materials to increase the performance of (electro)catalytic conversions

• Applicant: Dr. Lukas Fischer
• Subject Area: Physical Chemistry of Solids and Surfaces, Material Characterisation ; Polymer Materials
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 530864107

Porous materials are key components in technologies that could solve the need for low carbon energy (electrodes in CO2 reduction) or could combat the increasing environmental pollution and fresh water shortages (catalytic membranes for wastewater treatment). For these applications, highly porous composite materials are needed that incorporate active species like catalytic metal nanoparticles. So far, the state-of-the-art manufacturing approaches limit the control over the resulting porous structure and the tuning of the chemical environment around catalytically active sites. In this project, a fabrication process based on film casting and subsequent phase separation will be further developed towards a platform that can access porous multi-composite materials (PMCMs) with tailored properties. Functional particles and polymers will provide the PMCMs with catalytically active sites, electrical conductivity, adsorption sites, ion-exchange properties as well as particle anchoring function for combined synergistic effects. In a published preliminary work, the applicant already showed the synthesis of polyethersulfone based porous thin films that incorporate nickel nanoparticles, carbon nanoparticles and a positively charged ionomer. Dependant on the phase separation conditions, different pore structures were formed and a high component loading was achieved. By employing these PMCMs as flow-through membrane reactors for the continuous degradation of p-nitrophenol the applicant could show that the addition of carbon particles and cationic ionomer optimized the nickel microenvironment in the material which resulted in up to 10 times higher turnover frequencies compared to the individual nickel particles. The carbon nanoparticles also introduced electrical conductivity into the porous thin films and PMCMs with copper as catalyst particles were already successfully used as gas diffusion electrodes for the electroreduction of CO2. In the beginning of this project, this new fabrication process will be further optimized to independently adjust the morphology and chemical composition of materials. Of special interest is the investigation of the phase separation mechanisms of this complex system and how the different components are incorporated into the polymer matrix. The resulting PMCMs will be used as catalytic membranes for the hydrodechlorination of wastewater and as electrodes in the electrocatalytic CO2 reduction with a focus on using application-tailored materials. Furthermore, this project lies the foundation for the establishment of these novel PMCMs as active porous materials that could be used in later projects as heterogeneous catalysts for demanding reactions or additionally as electrodes in water electrolyzers or batteries.

• DFG Programme: Research Grants
• Co-Investigators: Professorin Dr.-Ing. Corina Andronescu; Professor Dr. Mathias Ulbricht