Synergistic Effects of Strain and Oxygen Vacancies in Nanofiber Electrodes for Enhanced High-Temperature Electrochemical Ethane Dehydrogenation

Direct ethane dehydrogenation (EDH) via protonic ceramic electrolysis cells (PCEC) represents a promising strategy for ethylene production. The practical application of this technique nevertheless is hindered by the scarcity of high-performance anode materials. In this work, PrBa_0.5Sr_0.5Co_1.5Fe_0.5O_5+δ (PBSCF) nanofibers are synthesized as PCEC anodes, which exhibit high activity toward EDH, achieving an ethylene selectivity as high as 93.8% and an ethane conversion of 63.7% at 535 mA cm^-2 and 700 °C. The combination of advanced spectroscopic techniques and density functional theory calculations reveals the presence of compressive strain in the nanofibers. This strain weakens the metal-oxygen bonds and shifts the O 2p band center closer to the Fermi level, thereby facilitating the formation of oxygen vacancies. The synergistic effect of compressive strain and oxygen vacancies enhances C₂H₆ adsorption and promotes the dehydrogenation steps for C₂H₄ production. The obtained knowledge can be broadly applied to the design of nanostructured electrocatalysts for other high-temperature electrochemical devices.