Effect of increasing Fe catalytic decomposition layer of ammonia on the performance and stability of ammonia electrode

Abstract

In a direct ammonia proton ceramic fuel cell (DA-PCFC), attaching a catalyst layer on the surface of the ammonia electrode is known to optimize the cell's electrochemical performance and long-term stability. In this study, the Fe catalyst layer is added to the ammonia electrode of the full cell which is prepared with the structure Ni– BaZr0.1Ce0.7Y0.1Yb0.1O3-δ(BZCYYb) (support layer)|Ni-BZCYYb (active layer)|BZCYYb|La0.6Sr0.4Co0.2Fe0.8O3-δ to investigate its impact on the electrochemical performance and stability of the electrode. Under the conditions of 700 oC and 20 ml min−1 ammonia fuel, the peak power densities of cells with and without the Fe layer reach 585.051 and 463.671 mW cm−2, respectively. It is evident that the addition of the Fe catalytic layer significantly improves the electrochemical performance of the cell. Stability tests are carried out for cells with and without the Fe layer at 650 oC, 0.36 A cm−2, and 0.32 A cm−2 constant current discharge. After discharge for 313 and 372 h, both cells show good stability, and the discharge curves of the two cells are consistent after 100 h. The high M-N binding energy of the Fe catalytic layer improved the initial performance of the cell, but this improvement is not sustained over the stability.