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 La0.5Sr0.5FeO3−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.