Direct ammonia protonic ceramic fuel cells through heterogeneous interfaces engineering

Ammonia, as an ideal carbon-free hydrogen carrier, enables direct application in protonic ceramic fuel cells while bypassing energy-intensive hydrogen regeneration. However, conventional Ni-based anodes for direct ammonia protonic ceramic fuel cells (DA-PCFCs) suffer from weak interfacial coupling and structural instability. Herein, we report a strategy of anodic heterogeneous engineering to build a strongly coupled Ni-BaZr_0.1Ce_0.7Y_0.1Yb_0.1O_3-δ interface combined with a Cs₂O-decorated Ru catalyst for surface modification. This design enhances ammonia decomposition by providing a highly interconnected network that facilitates efficient proton conduction and electron transfer, while the Ru catalyst introduces abundant active sites with superior ammonia adsorption capacity. The cell delivers a peak power density of 1.01 W cm⁻² at 650°C and maintains 98.1% of its initial ammonia decomposition activity after 200 h at 500°C of operation. By overcoming the bottlenecks of DA-PCFCs, this study paves the way for their practical application in carbon-neutral energy systems.