Tritium Sequestration in Gen IV NGNP Gas Stream via Proton Conducting Ceramic Pumps

Several perovskite structured proton conductors based on SrCeO₃ and BaCeO₃ have been investigated in the project. The solid solutions for SrCeO₃ and BaCeO₃ were first investigated. The morphological and electrical properties of Ba_1-xSr_xCe_0.8Y_0.2O_3-δ with x varying from 0 to 1 prepared by a modified Pechini method were investigated as potential high temperature proton conductors. Dense microstructures were achieved for all the samples upon sintering at 1500ees)C for 5 h. The phase structure analysis indicated that perovskite phase was formed for 0≤x≤0.2, while for x larger than 0.5, impurity phases of Sr₂CeO₄ and Y₂O₃ appeared. The stability tests indicated that the resistance to boiling water for Ba_1-xSr_xCe_0.8Y_0.2O_3-δ was between that of BaCe_0.8Y_0.2O_3-δ and SrCe_0.8Y_0.2O_3-δ Due to the tendency of the reaction with CO₂ for both BaCe_0.8Y_0.2O_3-δ and SrCe_0.8Y_0.2O_3-δ, it was not surprising that Ba_1-xSr_xCe_0.8Y_0.2O_3-δ was also not stable in CO₂ containing atmospheres. The conductivity tests indicated that Ba_1-xSr_xCe_0.8Y_0.2O_3-δ possessed the electrical conductivity between BaCe_0.8Y_0.2O_3-δ and SrCe_0.8Y_0.2O_3-δ. The conductivity decreased and the activation energy increased with the increase in Sr content in Ba_1-xSr_xCe_0.8Y_0.2O_3-δ.