Improved electrochemical performance and durability of butane-operating low-temperature solid oxide fuel cell through palladium infiltration

Abstract

Low-operating-temperature solid oxide fuel cells (LT-SOFCs) with various kinds of fuel, such as hydrocarbons, biogas, natural gas, and oxygenated fuel has been an active SOFC research topic. However, conventional SOFC anodes comprised of nickel metal and yttria-stabilized zirconia composite (Ni-YSZ) experience rapid degradation when operated for the butane direct internal steam reforming (B-DISR), especially at a low temperature (LT) range. This study reveals that the impregnated Pd into the Ni-YSZ anode support of thin-film SOFCs (TF-SOFCs) is effective for achieving better performance and stability regarding the TF-SOFC in B-DISR at 600 degrees C. Adding Pd as a dopant into Ni-YSZ significantly promotes the catalytic activity due to the Pd-Ni alloy formation, both on the YSZ grain and the Ni grain surface. The electrochemical performance of cells without Pd (Ni-YSZ cell) and a Pd-infiltrated Ni-YSZ anode (Pd-Ni-YSZ cell) are compared at 600 degrees C for the B-DISR mode at a ratio of steam-to-carbon of 3. Finally, long-term durability tests were performed at 600 degrees C and under 0.15 A cm(-2). The Pd infiltration decreases the deterioration rate to 0.63 mV h(-1)after the first 80 hours of operation for the Pd-Ni-YSZ cell, which was a significant improvement from that of the Ni-YSZ cell, 3.75 mV h(-1)after 40 hours of operation.