A metal–oxide interface enhances the methane oxidative coupling reaction in a solid oxide electrolyzer
Abstract
At present, converting methane into valuable chemicals is highly desired for industrial application. Here, we demonstrate the in situ electrochemical conversion of methane (C1) into ethane and ethylene (C2) products in a solid oxide electrolyzer at ambient pressure at 850 °C. In this work, we prepare a series of perovskite materials La0.75Sr0.25Cr0.5Fe0.5+xO3−δ (LSCrFx, x = 0–0.1) by reduction pre-treatment, and exsolve metallic iron nanoparticles on the LSCrFx surface to improve their catalytic activity. With the exsolution of metallic iron nanoparticles, the current density with LSCrF0.075 reaches 1.29 A cm−2 at 1.4 V. Then, the conversion rate of methane is 11.7%, and the selectivity of C2 reaches 15.5%. We further certify a stable performance with no obvious degradation being observed after 96 h of high temperature operation and 7 redox cycles. This work displays a reliable electrochemical process for the conversion of methane into valuable chemicals.