NH3-Fed Patterned Electrode Solid Oxide Fuel Cell: Experimental Performance Characterization and Elementary Reaction Modeling

Abstract

Ammonia-fueled solid oxide fuel cells (SOFCs) have attracted the focus of researchers due to no carbon emissions in utilization. Understanding the reaction mechanism is vital for the design and optimization of NH3-fed SOFCs. However, the catalytic decomposition reactions involved in porous electrodes led to difficulty in distinguishing the anode reaction mechanism. In the present study, we utilized a patterned anode to obtain a designed triple phase boundary (TPB) and avoid the effects of porous electrodes. In the performance test, we found that the exchange current density of the NH3-fed SOFC was approximately 5% of that of the H2-fed SOFC under a similar working position at 700℃. The difference may mainly result from the limit of catalytic decomposition of NH3 caused by the narrow reactive area in the patterned electrode. A one-dimensional elementary reaction model was further developed to validate this hypothesis and to provide additional evidence for the reaction mechanisms of the NH3-fed SOFC.