Her supervisors were Anja Olafsen Sjåstad (UiO), Helmer Fjellvåg (UiO) and David Waller (Yara and NTNU).
The adjudication committee Poul Norby (DTU), Mari-Ann Einarsrud (NTNU) and Truls Norby (UiO), and the chair of defense was Harald Walderhaug (UiO).
Her main research findings
Oxides – alternative materials for platinum and rhodium capture
Pt-Rh (95-5 wt.%) catalysts are used in the industrial ammonia oxidation process, as one of the key steps in production of HNO3 – an important chemical for inorganic fertilizer industry. Due to the highly exothermic ammonia oxidation reactions, platinum and rhodium are lost into gas phase as PtO2 and RhO2. The current technology to mitigate these losses consist of Pd-Ni catchment gauzes, however, it suffers due to losses of expensive palladium. Oxides are interesting alternative materials for platinum and rhodium capture because they are relatively cheap and may perform better than current technology.
In this doctoral thesis, it has been shown that a range of oxides are good candidates for platinum capture, meaning they capture a significant amount of platinum at ammonia oxidation conditions, platinum is easily recovered from the products e.g. La2NiPtO6 and have preferred catalytic properties of not decomposing NOx gases (the main products of the ammonia oxidation process) and at the same time function as laughing gas (N2O) abatement catalysts. In this work, a new ternary neodymium platinate was discovered. In addition, insight to simultaneous platinum and rhodium capture at various temperatures and as a function of exposure time in part result from detailed characterization with X-ray photoelectron spectroscopy.
For more information, see the announcement.