formed catalysts for active, durable, and thermally stable ammonia protonic ceramic fuel cells at 550 °C

• Published in: Energy & environmental science 2024-05, Vol.17 (1), p.3433-3442
• Main Authors: Zhang, Hua, Xu, Kang, Xu, Yangsen, He, Fan, Zhu, Feng, Sasaki, Kotaro, Choi, YongMan, Chen, Yu
• Format: Article
• ISSN: 1754-5692; 1754-5706
• DOI: 10.1039/d4ee00219a

Ammonia protonic ceramic fuel cells (NH 3 -PCFCs) are promising and attractive energy-conversion devices owing to their high energy density, zero-carbon emission, and safety. The development of NH 3 -PCFCs, however, depends largely on the insufficient activity and poor durability of typical Ni-based anodes for ammonia decomposition, especially at low temperatures such as 550 °C. Herein, we report a self-assembled heterostructured Ru 0.95 Cu 0.05 Ni x (RCN) catalyst obtained through an in situ reaction between the surface-decorated Ru 0.95 Cu 0.05 nanoparticles and the Ni grain in the anode under typical processing conditions. At 550 °C, Ni-BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3 anode-supported PCFCs with RCN catalysts exhibit a high peak power density of 0.732 W cm −2 and a significantly enhanced durability of 100 h in NH 3 . Moreover, the cells demonstrate improved thermal stability compared with the bare cell during a 31-cycle thermal cycling test in NH 3 between 550 and 700 °C. The enhanced performance is likely attributed to the synergistic effects of Ru and Cu in RCN for NH 3 decomposition, resulting in a more vital interaction of NH 3 than that of the bare anode surfaces, as confirmed by NH 3 thermal conversion, electrochemical performance, and theoretical simulations. In situ formed hetero-structured catalysts are reported to enhance the activity, durability, and thermal stability of NH 3 -PCFC at low temperatures of 550 °C and/or below.