The deleterious effect of silicon species on the conductivity of ceria electrolytes is well documented in the literature. A simple process has been developed at Praxair that alleviates the negative effect of high concentrations of silicon species on the conductivity of ceria electrolytes. The impact of this process on the conductivity of commercially available doped ceria electrolyte powders is demonstrated and a likely mechanism for the reduction of the resistivity is proposed. The influence of this process on other properties of the ceria electrolyte is discussed. (c) 2006 Elsevier B.V. All rights reserved.