Ethane oxidative dehydrogenation with CO2 on thiogallates

Abstract

The CO₂-assisted oxidative dehydrogenation of ethane (ODH-CO₂) attracts a lot of research interest since it combines greenhouse gas utilization with the production of valuable chemicals. The present study demonstrates the potential of the novel non-classic catalysts, alkali thiogallates, in this reaction. The contribution also reports a novel solvothermal synthesis method to prepare crystalline KGaS₂ thiogallate materials. Despite the low surface area of the bulk KGaS₂ system, the material shows substantial activity in CO₂ to CO transformation with conversions in the range of 22–36% at 700–800 °C. The catalyst allows utilization of the co-produced hydrogen from ethane thermal cracking for CO₂ hydrogenation without substantially impacting ethylene yield even at 800 °C at the conversion level of ethane close to 70%. The catalyst demonstrates stable performance with insignificant coke formation. The structure of the KGaS₂ thiogallate material is fully conserved after the reaction. These results open a promising opportunity for the thiogallate materials as catalysts with moderate hydrogenation function, which are highly tolerant to the CO and highly reactive hydrocarbons environments.