Rational design of a dual-functional NiRu/Y2O3 catalytic layer for NH3-driven protonic ceramic fuel cells

Ammonia-driven protonic ceramic fuel cells (NH 3 -PCFCs) represent a paradigm shift toward carbon–neutral energy conversion, offering high efficiency and moderate operating temperatures. However, their practical viability is currently impeded by the sluggish kinetics of ammonia decomposition and the severe nitridation of conventional Ni-based anode. Herein, a rationally engineered bimetallic NiRu/Y 2 O 3 is reported as anode catalyst layer (ACL) designed to overcome these dual challenges. Through a synergistic combination of combustion synthesis and incipient wetness impregnation, the 30Ni0.5Ru/Y 2 O 3 catalyst is optimized to deliver exceptional NH 3 conversion of 81.77% and 95.83% at 500 and 550 °C, respectively, under a high gas hourly space velocity of 30,000 mL g cat -1 h −1 . Mechanistic investigations reveal that this enhanced activity stems from Ru-promoted hydrogen spillover coupled with increased surface basicity; this synergy weakens N-metal binding energy and facilitates rapid H 2 desorption. When integrated into NH 3 -PCFCs, the optimized ACL enables a remarkable peak power density of 621.11 mW cm −2 at 650 °C. Furthermore, the pre-decomposition of NH 3 by the ACL significantly mitigates Ni nitridation, reducing the cell degradation rate from 41.01% to merely 18.24% over 50 h of operation at 600 °C. This work not only presents a cost-effective, high-performance catalyst for ammonia decomposition but also validates a robust strategy for realizing durable and efficient NH 3 -PCFCs.