Effect of Steam on Ethane Electro-oxidative Dehydrogenation to Ethylene

The effect of water vapor (H₂O) on the electrochemical-oxidative dehydrogenation (e-ODH) of ethane (C₂H₆) to ethylene (C₂H₄) over a solid oxide fuel cell (SOFC) platform was studied. SOFC button cells with anodes infiltrated with the La_0.5Sr_0.5FeO_3−δ (LSF0.5) electrocatalyst were operated under dry and humid conditions. Humidification had an inhibitory effect on C₂H₄ yield at 700 °C, with no impact at 750 °C, led to notable differences in electrochemical performance, and corresponded to post-trial anode compositional differences. C₂H₄ production embodied energy under humidified conditions was estimated to be higher than at dry conditions due to energy expenditure to generate steam. Together, these results suggested that e-ODH processes benefit from using a dry C₂H₆ feed stream. Additional findings include potential evidence of H₂O-induced C₂H₆ reformation to hydrogen (H₂), and iron and iron oxide structures observed in the post-trial anodes may have significance in describing the underlying catalytic behavior.