A versatile salt evaporation reactor system for SOFC operando studies on anode contamination and degradation with impedance spectroscopy

Abstract

The dependence of the degradation kinetics in Ni–CGO (cerium–gadolinium oxide) solid oxide fuel cell (SOFC) anodes upon salt evaporation is demonstrated operando with a custom built versatile reactor system. The system is based on evaporation and subsequent condensation of low concentration salt vapor aerosol mixtures representative of salt vapors typically present in biomass gasification processes. Fast changes in the charge transfer and ohmic resistance are observed in the anodes fuelled with a gas mixture containing a high KCl vapor concentration. Rapid condensation of salt vapors into the porous anode and partial delamination of the anode from the electrolyte surface because of salt deposits inside the porous anode is observed. The flexibility to produce vapor–aerosol mixtures with different concentrations and particle size distributions is proved, and suitability of these aerosols for anode testing in long term fuel cell test is evaluated.