Enhancing the Catalytic Activity of Ce(Mn, Fe)O2 on a Perovskite-Based Electrode via Spraying for High-Temperature CO2 Electrolysis

Abstract

Solid oxide electrolysis cells (SOECs) have tremendous potential to be highly efficient devices for high-temperature CO2 electrolysis. In general, the commonly used Ni-based cathodes suffer from inherent redox instability during direct CO/CO2 conditions. Therefore, the robust perovskite oxide La(Sr)Cr(Mn)O3 (LSCM) is suggested as an alternative due to its excellent coking resistance. However, the LSCM cathodes are limited due to their poor catalytic activity on CO2 reduction. [1] To alleviate this problem, the Ce(Mn, Fe)O2 (CMF) was added as a catalyst owing to the surface oxygen vacancy of CMF, which accelerates the chemical adsorption of CO2. [2] In this study, the solid direct injection process by ultrasonic spraying (SDI-USSP) is employed to fabricate the nano-decorated embedded CMF on LSCM surface as enhancing catalytic activity. The highly decorated electrode surface with CMF nano catalyst was embodied by an advanced one-step SDI-USSP without any complicated pretreatment and infiltration. We also analyzed the uptake of the catalytic activity and the ratio of CMF nanocatalysts through comparison with conventional composite electrodes. Consequently, when applied as a cathode for electrolyte-supported cells, the performances are measured at 1123 K, exhibiting a maximum power density of 1.349 W cm-2 in fuel cell mode (H2) and electrolysis performance of 2.756 A cm-2 at 1.5 V in CO2 reduction with high faradaic efficiency of nearly 94 %.