Abstract. Dehydrogenation of ethane to ethylene in the presence of carbon dioxide was investigated over various gallium-based catalysts. Ga2O3/HZSM-5 catalysts show better stability than b-Ga2O3, and the higher Si/ Al ratio HZSM-5 supported gallium oxide catalysts are more resistant to deactivation. The Ga2O3/HZSM- 5(97) catalyst exhibits both high activity and stability for dehydrogenation…