Atomically dispersed platinum electrocatalysts supported on gadolinia-doped ceria nanoparticles for practical high-temperature solid oxide cells

Abstract

Atomically dispersed catalysts provide excellent catalytic properties and atom utilization efficiency, but their high-temperature application has been limited by their low thermal stability. Herein, we report atomically dispersed Pt catalysts that are both highly active and thermally stable in fuel cells and electrolyzers operating above 600 °C. We developed a urea-based chemical synthetic method that strongly anchors atomic-scale Pt species on the surface of ceria nanoparticles and prevents their agglomeration at high temperatures. Doping the ceria with gadolinia further enhances their catalytic properties by increasing the oxygen vacancy concentration and promoting the oxygen exchange kinetics. This process enables in situ synthesis within the porous electrode of realistic solid oxide cells and significantly improves the power output and H₂ production rate in fuel cell and electrolysis modes, respectively. Furthermore, this electrode stably operated without noticeable degradation during a long-term evaluation, thus proving the excellent thermal stability of atomically dispersed Pt/ceria catalysts.