In-situ studies of CO2 hydrogenation catalysts
The escalating concentration of CO2 in the atmosphere due to anthropogenic activities necessitates effective mitigation strategies. This dissertation delves into the realm of carbon capture and utilization, focusing on the activation and conversion of CO2. The dissertation spans from equipment design and construction, catalyst synthesis and testing, and to a comprehensive characterization under various ex-situ, in-situ, and operando conditions. All of this to shed light on the intricate processes involved in CO2 conversion.
In general, three types of catalysts are explored in depth: Ni or Ru supported on high surface area magnesium oxide support and Ni on alumina support, both of these for CO2 to CH4. The third type of catalysts are a comprehensive study of Mn based catalysts for the conversion of CO2 into CO via the Reverse Water Gas Shift reaction. Through meticulous experimentation, including ex-situ, in-situ, and in operando characterization, the complexities of CO2 activation and conversion pathways are explored.
Notably, it is shown that our MgO is highly suitable for creating a top-of-the-shelf catalyst with Ru and Ni. It is furthermore shown that the impact of calcination and reduction temperatures of an archetypical Ni on alumina catalyst is key in order to understand the performance for CO2 conversion to CH4. Lastly, the role of Mn as the active metal in the Reverse Water Gas Shift reaction is examined.
Furthermore, the catalysts were studied with various infrared spectroscopy techniques. This allowed the study of the surface of the catalysts herby enabling a better understanding of the mechanism for CO2 utilization.
Principal Supervisor:
Professor Søren Kegnæs, DTU Chemistry
Co-supervisor:
Associate Professor Jerrik Jørgen Mielby, DTU Chemistry
Examiners:
Associate Professor Susanne Mossin, DTU Chemistry
Professor, Dr. Miquel Bañares, Insitute for Catalysis and Petroleumschemistry, Spain
Professor Christian Hulteberg, Lund University, Sweden
Chairperson:
Professor Kasper Steen Pedersen, DTU Chemistry