Flame-synthesized ceria- and titania-supported Co and Ni catalysts for CO2 hydrogenation
Angelina Evtushkova has successfully defended her PhD thesis at the Department of Chemical Engineering and Chemistry on May 13th.
This thesis explores how the composition and structure of certain materials influence their ability to convert carbon monoxide (CO) and carbon dioxide (COâ‚‚) into useful products like methane or carbon monoxide gas. The study focuses on materials based on cerium oxide and titanium oxide with small amounts of cobalt and nickel. These materials were made using a flame-based method and compared to more traditional techniques.
This research helps improve our understanding of how these materials work and support the development of new generation of catalysts for turning waste carbon into valuable chemicals.
The thesis investigates structure-activity relationships in CO/COâ‚‚ hydrogenation using CeOâ‚‚- and TiOâ‚‚-based catalysts modified with Co and Ni. Catalysts were synthesized via one-step flame spray pyrolysis (FSP) and compared with conventional wet impregnation (WI). By tuning Co/Ni content and particle sizes, the study explores the synergy between metals and supports, and its impact on active site structure, catalytic activity, and stability. Advanced techniques (NAP-XPS, XAS, STEM-EDX, etc.) were used to characterize catalysts under working conditions. Results show that metal nanoparticles enhance CHâ‚„ selectivity, while metal-oxide interfaces and clusters promote CO formation. The work supports catalyst design for carbon utilization and deepens insight into COâ‚‚ hydrogenation.
By varying the amounts of cobalt and nickel and adjusting the particle size, the research examines how these factors influence the material’s performance and stability during the conversion reactions. Advanced spectroscopy and microscopy were used to observe how the materials behave under reaction conditions.
The findings show that very small metal particles tend to produce more methane from COâ‚‚, while other structures prefer making CO.