(605a) Development of Iron-Based Perovskite Materials as Carbon and Sulfur Tolerant Solid Oxide Fuel Cell Anodes

Current Ni-based solid oxide fuel cells (SOFC) anodes deactivate in the presence of coal-derived gas because they are easily poisoned by low levels of sulfur and catalyze coke formation. In addition to these problems, the Ni-based anodes also lose activity through sintering. These processes deactivate the anodic reaction rates, cause low power densities, and increase operation costs due to large steam requirements. Thus, the development of highly active and carbon and sulfur tolerant materials suitable for use as anodes is necessary to bring coal-gas fed SOFC systems closer to commercialization.

Ongoing SOFC cathode research in our group shows iron-based perovskite materials are developed as promising materials for use as SOFC cathodes between 500°C and 700°C. The electrochemical activity and oxide ion mobility that make it desirable for cathode applications can also be harnessed for the oxidation reactions at the anode.

The current research demonstrates the iron-based perovskite materials are stable in highly reducing conditions and possess catalytic activity for the oxidation of hydrogen and carbon monoxide in the desired temperature range. The effect of the increased lattice oxygen mobility on the water requirements and the influence of hydrogen sulfide concentration on the oxidation activity are discussed. Characterization is performed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and vibrational spectroscopy to complement the anodic oxidation results.