Efficient ammonia conversion in proton conducting fuel cells: Combined application of dendritic anodes and nanofiber catalysts

• Published in: International journal of hydrogen energy 2024-10, Vol.85, p.715-725
• Main Authors: Dang, Haochen, Song, Laizhen, Shi, Guopu
• Format: Article
• Language: English
• Subjects: Ammonia fuel; Dendritic-channels anode support; Nanofiber catalyst; PCFCs
• ISSN: 0360-3199
• DOI: 10.1016/j.ijhydene.2024.08.321

Ammonia, with its high hydrogen content, serves as an optimal carbon-free medium for indirect hydrogen storage, making it ideal for fuel cells. Nevertheless, the limited anodic catalytic activity of Proton-conducting solid oxide fuel cells (PCFCs) significantly hampers NH3 utilization efficiency and overall performance. This study introduces efficient nano-catalysts deposited onto dendritic anodic microchannels, leading to the formation of an in-situ ammonia decomposition reactor for internal ammonia gas conversion. Compared to conventional cells, this cell, equipped with a catalyst bed, shows a 25% increase in peak power density and a 20%–30% enhancement in NH3 utilization efficiency. Additionally, ammonia undergoes efficient decomposition on anodic metallic nickel, which prevents nickel nitridation and improves cell stability. The augmented stability of these cells is evidenced by their prolonged operational lifespan under constant current conditions, extending from 63 to 108 h, thus marking a substantial enhancement in the system's durability and reliability. •Ammonia is a storable, hydrogen-rich, carbon-free fuel highly compatible with PCFCs.•"Ammonia replace efficiency” characterizes ammonia fuel utilization rate in PCFCs.•Dendritic porous anode enables efficient catalyst loading for ammonia decomposition.•Ru-GDC fiber catalysts in porous anodes enhance catalytic reformer performance.