Synergistic Effects of Strain and Oxygen Vacancies in Nanofiber Electrodes for Enhanced High-Temperature Electrochemical Ethane Dehydrogenation
Yongjian Ye, Xuepeng Xiang, Zilin Ma, Nian Zhang, Shijun Zhao, Wonyoung Lee, Youmin Guo, J. Milewski, Yan Chen
Abstract
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 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 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 C 2 H 6 adsorption and promotes the dehydrogenation steps for C 2 H 4 production. The obtained knowledge can be broadly applied to the design of nanostructured electrocatalysts for other high-temperature electrochemical devices.