Lichtinduzierte elektrokatalytische CO2-Reduktion zu Ethylen mit molekularen, über CH-π-Wechselwirkungen auf polymeren organischen Absorbern verankerten Katalysatoren
Festkörper- und Oberflächenchemie, Materialsynthese
Zusammenfassung der Projektergebnisse
The need for sustainable energy sources and sustainably produced feedstock in times of energy crisis is more urgent than ever. This urgency is no longer arising only from an ecologic point of view, but also from an economic point of view and in terms of safety and reliability. Since the CO2 reduction reaction (CO2RR) has the potential to prevent further increase of the carbon dioxide content in the atmosphere while producing valuable fuels and feedstock, the development of new high-performance CO2RR (photo-)electrocatalysts is desirable. Utilizing molecular metal complexes as homogeneous catalysts in catalytic systems offers several advantages. These catalysts provide a well-defined active site, allowing for rational catalyst design by tailoring the ligand. By anchoring these molecular catalysts to surfaces, the benefits of homogeneous catalysis, such as tunability and selectivity, can be combined with the advantages of heterogeneous catalysis, including easy catalyst separation/recycling and long lifetime. The aim of the project was to heterogenize a novel first row transition metal complex catalyst onto an electrode surface. After the proposed anchoring of an iron porphyrin complex via CH-π-interactions has not been successful, electropolymerization of a novel cobalt complex has been performed. The resulting electrode has proven to be an active electrocatalytic system for the CO2RR. In in-depth-analysis of the system before and after catalysis through cyclic voltammetry, Raman spectroscopy, SEM Microscopy, EDX mapping, and XAS(EXAFS) via Raman spectroscopy its nature and durability has been analysed. It turned out, that the molecular catalyst has to be optimized before the planned generation of a catalytically active photocathode will be performed.
