Improving single-chamber performance of an anode-supported SOFC by impregnating anode with active nickel catalyst

In order to improve the single-chamber performance of a traditional anode-supported single-chamber solid-oxide fuel cell with NiO-ScSZ anode and ScSZ electrolyte, the modification of the anode with a fine nickel catalyst by impregnation method was exploited. Catalytic test demonstrated the nickel catalyst had higher catalytic activity than the severe sintered nickel-cermet anode between 700 and 900 °C, especially at the lower temperature range. SEM examination demonstrated the nickel catalyst impregnation increased the roughness of the nickel grains within the anode. Furthermore, some surfaces of the ScSZ grains are also covered with very fine nickel catalyst. By operating on a methane-air mixture gas with methane to oxygen ratio of 1.3:1, the cell with its anode impregnated with the nickel catalyst showed an open circuit voltage and peak power density of 0.954 V and 119 mW cm^-2 at a furnace temperature of 750 °C, respectively, as a comparison of 0.893 V and 79 mW cm^-2 for the cell without the nickel catalyst. The improved cell performance was attributed to the higher cell temperature and increased anode catalytic activity for methane partial oxidation.