#EBSstories Greek scientists monitor novel catalysts that convert carbon dioxide

Solid Metal Oxide Catalysts used for the conversion of CO₂ and ethane are widely researched for their positive impact. They enable the transformation of a greenhouse gas responsible for climate change, into valuable products like ethylene and CO, thereby providing a means of carbon recycling and reducing emissions. At the same time, the ethylene produced is necessary for the production of chemicals, such as plastics, needed in different industries.

Despite extensive investigations, scientists still have not been able to follow the catalytic reaction in-situ, while monitoring the changes of the catalyst structure in total. “Our theoretical predictions state that we can expect changes, but if we want to find proof of them, we need to find a beamline like ID20 at the ESRF, and there are not many in the world”, explains Stavros- Alexandros Theofanidis, researcher at the University of Thessaloniki in Greece. “We have tested our catalyst using lab techniques, but we can’t conclude what exactly happens in action”, he adds.

The way the catalyst probably works is by hydrogen abstraction, activating the C-H bond of ethane, and thus forming ethylene. Hydrogen abstraction removes oxygen from the surface or lattice of the catalyst forming H₂O. CO₂ replenishes the oxygen vacancy, generating CO.

On ID20 the team can study the low Z elements, such as oxygen and magnesium, which can provide structural information about the changes in catalyst.

“The research at ESRF offers unique opportunity to study in depth the reaction mechanism and the associated structural changes of the catalyst, and I think having the possibility to get access to a facility like this, especially with ESRF-EBS, would really boost Greek research”, Theofanidis explains. “We have kept a long-standing collaboration with the ESRF and we hope it will even get stronger in the future”, he adds.  

The team, together with ESRF scientists, recently published the paper: 'Tandem CO₂ valorization and ethane dehydrogenation: Elucidating the nature of highly selective iron oxide active sites' in ACS Catalysis.  “The findings from the ESRF can boost not only chemistry and chemical engineering but the fields of physics and biology”, concludes Theofanidis.

Text by Montserrat Capellas Espuny

Top image: Maria Tasioula placing a sample on ID20. In the background, Stavros-Alexandros Theofanidis.