A method is provided for adding sulfur to a solid oxide fuel cell (SOFC) stack having a Ni--YSZ anode to prolong the life of the SOFC stack. The method includes the steps of providing a reformate stream essentially free of sulfur compounds, feeding the reformate stream to the SOFC stack, and adding a predetermined amount of a sulfur compound into the reformate stream upstream of the SOFC stack. The predetermined amount of the sulfur compound is effective to prolong the life of the Ni--YSZ anode by retarding the formation of carbon onto the Ni--YSZ anode and the coarsening of the granular microstructure of the Ni--YSZ anode, while minimizing the degradation of power output of the SOFC stack within a predetermined limit.
 This invention was made with the United States Government support under Contract DE-FC26-02NT41246 awarded by the U.S. Department of Energy. The Government has certain rights in this invention.