Disputation: Dimitrios Pappas
Msc. Dimitrios Pappas at the Department of Chemistry, Faculty of Mathematics and Natural Sciences, is defending the thesis ‘Direct Methane to Methanol Conversion over Cu-Exchanged Zeolites: Building Structure - Activity Relationships for the degree of Philosophiae Doctor.
December 13th, 10:15 AM, Auditorium 3, Kjemibygningen
"Overview of catalysts for methanol synthesis from carbon dioxide – structure to property relations."
I denne avhandlingen har vi undersøkt Cu - zeolitter for direkte konvertering av metan til metanol. Utviklingen av en slik prosess kan ha betydelige samfunnsøkonomiske og miljømessige fordeler og er derfor et viktig forskningsområde.
Våre fokusområder var å få en innsikt i egenskapene til materialene, samt prøve å forstå mekanismen bak konverteringen.
Disse målene ble oppnådd ved å kombinere testing av aktiviteten til materialene med et bredt spekter av spektroskopiteknikker.
The direct conversion of methane to added value chemicals and in particular methanol, is a topic intensively researched by the academia and the industry due to large environmental and economic benefits. Such a process can act as an alternative to the capital- and energy-intensive syngas route for methanol synthesis as well as contribute in reducing methane flaring. To this aim different catalytic processes have been investigated over the past decades.
In this thesis, copper loaded zeolites are investigated for the direct conversion of methane to methanol. Zeolites, which have numerous applications in catalysis, are microporous aluminosilicates with defined structures able to host active metal centers. The conversion of methane to methanol over copper exchanged zeolites is a stepwise process. Initially the material is pre-treated in oxygen at high temperature, then methane activation takes place at a lower temperature and finally methanol is extracted by hydrolysis of the stabilized intermediate. Different copper exchanged zeolites have been investigated, including chabazite, ferrierite and mordenite, aiming to understand the mechanism of the conversion as well as the fundamental properties of the materials. These are achieved by combining activity measurements with in situ and operando characterization techniques and establishing structure activity relationships.