- Previous Article
- Next Article
- Table of Contents
Chinese Journal of Chemical Engineering, Vol.15, No.3, 305-308, 2007
Investigation of cathode catalysts for intermediate-temperature H2S-air fuel cells
Cathode catalysts comprising composite NiO, NiO-Pt, or LiNiO2 have been developed for electrochemical oxidation of hydrogen sulfide in intermediate-temperature solid oxide fuel cells (ITSOFCs). All catalysts exhibited good electrical conductivity and catalytic activity at operating temperature. Composite NiO catalysts were found to be more active and have lower over potential and higher current density than pure Pt although the electrical conductivity of NiO itself is lower than that of Pt. This problem has been overcome by either admixing as high as 10% (by mass) Ag powder into NiO cathode layer or using composite NiO catalysts such as NiO-Pt and LiNiO2 catalysts. Composite catalysts like NiO with Ag, electrolyte and starch admixed, NiO-Pt, which was prepared from a mixture of NiO and Pt powders, by admixing electrolyte and starch, and LiNiO2, which is derived from the reaction of LiOH center dot H2O and NiO with electrolyte and starch admixed have been shown to be feasible and effective in an intermediate-temperature H2S-air fuel cell. A fuel cell using Li2SO4-based proton-conducting membrane as electrolyte, metal sulfides as anode catalysts, and composite NiO as cathode catalysts produced a maximum current density about 300mA center dot cm(-2) and maximum power density over 80 mW center dot cm(-2) at 680 degrees C.