In Situ Exsolved Ni Nanoparticles From Pr0.5Sr0.5Ti0.5Mn0.5O3 with Varying Ni Doping Levels for Direct Methane Solid Oxide Fuel Cells

Why It Matters

The findings provide a pathway to more efficient, carbon‑tolerant SOFC anodes, accelerating methane’s role as a clean power source. This could lower operating costs and expand SOFC deployment in existing natural‑gas infrastructure.

Key Takeaways

• Ni doping yields exsolved Ni nanoparticles.
• PSTMN41 shows highest power density in CH4.
• Oxygen vacancies boost electron transport.
• Stable operation for 120 hours in humidified methane.
• Reduced carbon deposition improves anode durability.

Pulse Analysis

The integration of nickel into the perovskite lattice of Pr0.5Sr0.5Ti0.5Mn0.5O3 creates a dual‑benefit architecture: nanoscale metallic particles and a high density of oxygen vacancies. During hydrogen reduction, nickel exsolves to the surface, forming uniformly dispersed nanoparticles that act as active sites for methane activation. Simultaneously, the vacancy‑rich matrix enhances ionic conductivity, facilitating rapid charge transfer across the anode‑electrolyte interface. This synergy addresses two longstanding challenges in solid oxide fuel cells—catalytic sluggishness on hydrocarbon fuels and carbon coking that degrades performance.

Performance metrics underscore the practical impact of this design. PSTMN41 achieved a peak power density of 60.7 mW·cm⁻² on humidified methane at 850 °C, rivaling traditional Ni‑cermet anodes while maintaining a polarization resistance below 2.5 Ω·cm². Notably, the cell sustained stable output for over 120 hours without detectable carbon buildup, a testament to the protective effect of the exsolved nanoparticles and the oxygen‑deficient lattice. These results suggest that nickel‑doped perovskites can replace or augment conventional anodes, offering comparable power with enhanced durability under hydrocarbon operation.

Beyond the laboratory, the technology aligns with broader energy transition goals. Methane, abundant and supported by extensive distribution networks, can serve as a bridge fuel if converted efficiently and cleanly. Deploying SOFCs with PSTMN41‑type anodes could lower the levelized cost of electricity from natural‑gas‑derived power, reduce greenhouse‑gas emissions relative to combustion, and enable distributed generation in remote or off‑grid settings. As the industry seeks carbon‑resilient solutions, nickel‑exsolved perovskite anodes represent a compelling, scalable option for next‑generation high‑temperature fuel cells.