In situ synthesis of cobalt-embedded gadolinia-doped ceria nanocatalysts for high-temperature solid oxide cells

Abstract

High-temperature solid oxide cells (SOCs) provide a highly efficient route for power generation and hydrogen production. In this study, we develop cobalt-embedded gadolinia-doped ceria nanocatalysts that significantly enhance the performance of nickel-based fuel electrodes of SOCs. These nanocatalysts are synthesized in situ within the pores of the electrode using a urea-based infiltration process. Doping gadolinia into the ceria lattice improves the oxygen ionic conductivity, and uniform gadolinia-doped ceria nanoparticles, 20–30 nm in size, consistently form within both symmetric and full cells. Meanwhile, a portion of the cobalt also forms discrete nanoparticles, less than 10 nm in size, further boosting catalytic activity. The electrochemical performance of the full cells is improved by approximately 30% and 60% in fuel cell and electrolysis mode operations, respectively. Additionally, the cell operates stably for 300 h under a constant electrolysis current of −1.0 A cm⁻² at 700 °C, demonstrating that the nanocatalysts remain stable under harsh high-temperature conditions.