PNNL

Abstract

A multi-functional NiMo-ceria-zirconia composite was developed as an anode for a solid oxide fuel cell (SOFC) running on isooctane that is a commonly used model fuel for gasoline. The anode layer was fabricated on an electrolyte-supported single cell using yttria-stabilized zirconia (YSZ) as the electrolyte and La0.6Sr0.4Co0.2Fe0.8O3-d as the cathode. Our results indicated that the single NiMo-ceria-zirconia layer possessed a dual-functionality: the first function was to internally convert complex hydrocarbons into a synthesis gas and the second function was to electrochemically oxidize the synthesis gas mixture for electric power generation. The addition of Mo to the Ni-ceria-zirconia allowed direct conversion of isooctane in SOFC. It significantly suppressed carbon deposition in the anode and improved the lifetime of a single cell. Additionally, the presence of Mo in the Ni-ceria-zirconia anode appeared to facilitate a higher degree of sintering, which increased the electrical conductivity and maximum power density of the single cell. When operating on isooctane at 800 °C, single cell with the 5 wt.% Mo in the Ni-ceria-zirconia-based anode displayed a maximum power density of 212 mW cm-2 at 0.48V which was higher than that of a single cell with the Ni-YSZ-based anode without the Mo promoter (49 mW cm-2 at 0.48 V).