FPU2023-Structural and chemical analysis of heterogenous catalysts for CO2 hydrogenation

Carbon dioxide is one of the greenhouse gases responsible for the climate change. Avoiding or reducing CO2 production is one of the key points for stopping this environmental problem. CO2 can be converted into value-added fuels like methanol by heterogeneous catalysis. This reaction requires energy and if renewable energies are used for such a process, a storable fuel can be produced. The produced methanol can be stored and handled easily. In the case of CO2 hydrogenation reaction, this requires an appropriate catalyst to have an efficient energy turnover. Among other types a combination of copper and transition metal oxides is used. Two of the best suited combinations are cerium oxide/copper and zinc oxide copper. Here, several experimental techniques (STM-scanning tunnelling microscopy, LEED-low energy electron diffraction, XPS X-ray photoelectron spectroscopy) will be used to study in detail the growth of the catalyst material and probe its chemical properties. The experimental study will be carried out at model systems grown on curved substrates under ultra-high vacuum (UHV) conditions using STM and LEED for structural analysis as well as XPS at UHV and near-ambient pressure photoemission for chemical properties. Two types of catalysts will be probed, Cu nanoparticles on the oxide surfaces (normal catalyst) and oxide nanoparticles on the copper surface (inverted catalyst). Further metal nanoparticle will be probed to increase the effectivity of the reaction.