Nano-LaCoO3 infiltrated BaZr0.8Y0.2O3− electrodes for steam splitting in protonic ceramic electrolysis cells

Abstract

Protonic ceramic electrolysis cell (PCEC) is a promising technology for production of pure dry hydrogen due to the low operating temperature and high efficiency. One of the obstacles for commercialization of PCEC technology is the poor performance and insufficient long-term durability of the oxygen electrode. In this study, we address the above challenge by designing a LaCoO3 (LC) catalyst infiltrated porous BaZr0.8Y0.2O3−δ (BZY20) backbone electrode (LC-BZY20). The performance and durability of the LC-BZY20 electrode are investigated on symmetrical cells using electrochemical impedance spectroscopy (EIS). The total electrode polarization resistance (RP) values of the electrode are 0.56, 1.24, 2.18, and 2.90 Ω cm2 in 3 ​vol% humidified synthetic air at 600, 550, 500, and 450 ​°C, respectively, indicating good electrochemical performance of the LC-BZY20 electrode. Furthermore, the LC-BZY20 electrode displays good stability, without significant performance degradation when tested at 600 ​°C in 10 ​vol% humidified air for 900 ​h. We further study the influence of oxygen partial pressure (Po2) and steam partial pressure (PH2O) on the response of the EIS data, and propose a set of chemical and electrochemical processes involved in the steam splitting reaction in the LC-BZY20 electrode.