The Disputation will be live streamed for everyone else.
The livestream will be activated 15 minutes before the Defense starts.
Trial lecture
November 7th, 10:15AM, Auditorium 3, Chemistry building
Trial lecture title: "The chemistry of quantum materials"
Kreeringssammendrag/Conferral summary
Fangst av edelmetallene platina og rhodium i ammoniakkoksidasjonsprosessen gjør produksjon av nitrogenbasert kunstgjødsel mer bærekraftig ved å fasilitere sirkulærøkonomi. Dette doktorgradsarbeidet har undersøkt hvordan oksider muligens kan forbedre og/eller erstatte dagens fangstteknologi ved å studere hvor gode oksider er på å reagere med PtO2(g) og RhO2(g) samt hvor kompatible de er med industrielle ammoniakkoksidasjonsbetingelser. Dette ble oppnådd ved blant annet å utføre en rekke lab-skala og pilot-skala fangsteksperimenter, etterfulgt av detaljert karakterisering med f.eks. røntgenfotoelektronspektroskopi (XPS).
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.
Candidate contact information
LinkedIn: https://www.linkedin.com/in/julie-hessevik-2b303385
E-mail: julie.hessevik@kjemi.uio.no
Phone: +47 91368172
Adjudication committee
Professor Poul Norby
Department of Energy Conversion and Storage, Technical University of Denmark, Denmark
Professor Mari-Ann Einarsrud
Department of Materials Science and Engineering, NTNU, Norway
Professor Truls Norby
Department of Chemistry, University of Oslo, Norway
Supervisors
Professor Anja Olafsen Sjåstad
Department of Chemistry, University of Oslo, Norway
Professor Emeritus Helmer Fjellvåg
Department of Chemistry, University of Oslo, Norway
Chief Expert Catalysis and Professor II David Waller
Yara Norge AS and NTNU, Norway
Chair of defence
Professor Harald Walderhaug
Department of Chemistry, University of Oslo, Norway