Electrochemical characteristics of La 0.8Sr 0.2Cr 0.82Ru 0.18O 3− δ–Gd 0.1Ce 0.9O 2 solid oxide fuel cell anodes in H 2–H 2O–CO–CO 2 fuel mixtures

Abstract

This paper describes the performance of composite La 0.8Sr 0.2Cr 0.82Ru 0.18O 3− δ –Gd 0.1Ce 0.9O 2 anodes operated in varied H 2O–H 2, CO–CO 2, and H 2O–H 2–CO–CO 2 fuel mixtures. Impedance spectroscopy studies in both H 2O–H 2 and CO–CO 2 showed two main impedance responses that were thermally activated and exhibited power law variation with gas partial pressures. The polarization resistances in CO–CO 2 mixtures were larger than in H 2–H 2O mixtures with the same partial pressure ratios. Polarization resistances for surrogate coal syngas H 2O–H 2–CO–CO 2 fuel mixtures were higher than for H 2O–H 2–Ar mixtures with the same H 2 and H 2O partial pressures, indicating that CO or CO 2 interfered with the H 2 oxidation reaction.