Ultrasonic spraying of Ce(Mn,Fe)O2 nanocatalysts onto a perovskite surface for highly efficient electrochemical CO2 reduction

Abstract

Solid oxide electrolysis cells (SOECs) are promising devices for application in electrochemical CO₂ reduction towards achieving a carbon-neutral society. However, the low durability of Ni-based electrodes during CO₂ electrolysis hinders their commercial viability. Here, a fuel electrode with a nano-convex structure, i.e., (La_0.75Sr_0.25)_0.97Cr_0.5Mn_0.5O₃@Ce_0.6Mn_0.3Fe_0.1O₂ (LSCM@nano-CMF), is designed with an all-ceramic phase to enhance the electrochemical activity by following a simple and scalable approach. Ultrasonic spraying enables one-step formation of uniform nano-electrodes, contrasting with the tedious, consumable, and typically hired multi-step infiltration process. The excellent performance (3.89 A cm⁻² at 1.5 V in the CO₂ electrolysis at 850 °C) attributed to the CMF nanocatalyst with abundant oxygen vacancies and the unique perovskite/fluorite interface in a regulated structure, accelerating CO₂ adsorption and displaying the synergistic catalytic effect of the dual phases. Additionally, the durability and coking tolerance of the LSCM@nano-CMF fuel electrode are demonstrated for 180 h, with a high faradaic efficiency of nearly 92%. This work provides insights for using SOECs for large-scale applications in CO₂ reduction.