Strontium Titanate based SOFC anodes with nano scaled electrocatalysts

Ceramic SOFC anodes with nano scaled electrocatalyst particles are of current interest for low temperature application of SOCs and to increase robustness in terms of redox stability and coking tolerance. Strontium titanates are a materials class that is compatible with the state-of the art electrolyte yttria stabilized zirconia and possesses sufficient electronic conductivity under reducing conditions that make them attractive for SOC fuel electrodes. However, their electrocatalytic activity is rather poor and nano scaled electrocatalyst particles are infiltrated into the porous strontium titanate to achieve technically relevant performance. Various electroactive materials have been explored by infiltration into Strontium titanates. Ni, Co and Fe with and without ceria-gadolinia (CGO) have been infiltrated as metal particles into two different Strontium titanates, A-site deficient La-Sr-C-titanate (LSCT) modified with different elements (Cr, Mn, Zn) on the B-site and Niobium modified Strontium-titanate (STN). Zn substitution showed a positive effect on the pure LST electrodes and electrode area specific resistances down to 0.2 Ω∙cm² have been achieved for LST-Zn electrodes infiltrated with Ni-CGO. The influence of backbone vs. electrocatalyst on the electrode performance will be presented in this contribution.