LAUSR

The aim of the present study is the measurement and understanding of sulfur poisoning phe-nomena in Ni/gadolinium-doped ceria (CGO) based solid oxide fuel cells (SOFC) operating on reformate fuels. The sulfur poisoning behavior of commercial, high-performance electro-lyte-supported cells (ESC) with Ni/Ce0.9Gd0.1O2‒(CGO10) anodes operated with different fuels was thoroughly investigated by means of current-voltage characteristics and electro-chemical impedance spectroscopy, and compared with Ni/Yttria-stabilized zirconia (YSZ) anodes. Various methane- and carbon monoxide-containing fuels were used in order to eluci-date the underlying reaction mechanism. The analysis of the cell resistance increase in H2/H2O/CO/CO2 fuel gas mixtures revealed that the poisoning behavior is mainly governed by an inhibited hydrogen oxidation reaction at low current densities. At higher current densities, the resistance increase becomes increasingly large, indicating a particularly severe poisoning effect on the carbon monox...