Ba(Zr, Ce)O3-based proton-conducting solid oxide electrolysis cells for efficient hydrogen production

Abstract

Proton-conducting solid oxide electrolysis cells (H-SOECs) have emerged as a key technology for renewable energy-driven hydrogen production and offer unique advantages of low proton migration activation energy, low operating temperatures (<600 °C), and the ability to produce dry hydrogen directly. Nevertheless, the practical application of H-SOECs remains hindered by several critical issues such as the limited chemical stability of the electrolyte and degradation of the electrode/electrolyte interface. While Ba(Zr, Ce)O₃-based proton conductors are extensively studied as the electrolytes, BaZrO₃-based materials offer distinctly superior chemical stability, making them a critically important class of electrolytes for highly durable H-SOECs. This review provides a comprehensive review of the latest research progress in Ba(Zr, Ce)O₃-based H-SOECs, with particular emphasis on the BaZrO₃-based systems. It focuses on the material and structural design of the cell components, including electrolyte materials, hydrogen electrodes, oxygen electrodes and the electrode/electrolyte interface. Besides, in-depth perspectives on ongoing challenges and future research directions are provided, particularly on the design of highly efficient and stable electrode materials toward high-performance large-area electrolysis cells for hydrogen production.