Redox-Stable Electrodes for Ethane Dehydrogenation Based on Proton Ceramic Electrochemical Reactors

Abstract

Ethylene is one of the most widely used components in the chemical industry, but the main manufacturing route involves significant energy consumption and generates substantial CO₂ emissions. Proton ceramic electrochemical reactors (PCERs) offer great potential for process intensification and could play a key role in ethane dehydrogenation (EDH) by extracting H₂ produced during the reaction. This process not only improves the reaction yield but also enables the production of a pure separated H₂ stream. However, nonoxidative EDH reaction conditions lead to coke formation, which is further increased by H₂ extraction, resulting in a decrease in system performance. Therefore, to successfully integrate PCER technology into ethylene production, it is crucial to develop stable redox electrodes that can withstand both nonoxidative H₂ extraction and coke oxidation conditions. In this work, we study different composite electrodes based on the perovskite La_0.8Sr_0.2Cr_0.5Mn_0.5O_3−δ (LSCM) combined with the proton conductor BaCe_0.55Zr_0.3Y_0.15O_3−δ (BCZY₅₅₁₅). The electrochemical performance was characterized by using electrochemical impedance spectroscopy under both oxidizing and reducing conditions. The data analysis indicates that surface processes limit electrode operation. The infiltration of Pt and CeO₂ nanoparticles in the electrode enhanced the electrochemical performance, improving it by a factor of 10 at 700 °C. The optimal electrochemical performance was observed for the LSCMF/BCZY₅₅₁₅ (La_0.8Sr_0.2Cr_0.5Mn_0.25Fe_0.25O_3−δ/BaCe_0.55Zr_0.3Y_0.15O_3−δ) electrode infiltrated with Pt/CeO₂, demonstrating promising properties as a redox-stable electrode. Finally, we evaluated the nonoxidative EDH reaction using a PCER based on a Ni–SrZr_0.5Ce_0.4Y_0.1O_2.95 (SZCY541) supported cell with a LSCMF/BCZY₅₅₁₅ anode infiltrated with Pt/CeO₂ and a thin BaZr_0.44Ce_0.36Y_0.2O_3−δ electrolyte.