Dimethyl ether fueled intermediate temperature SOFC using LaGaO3-based perovskite electrolytes

Abstract

Intermediate temperature solid oxide fuel cells (SOFCs) fueled with dimethyl ether (DME) were investigated. The performance of a single cell, Ni/La0.9Sr0.1Ga0.8Mg0.2O3 /Sm0.5Sr0.5O3, fueled with DME was comparable to that of the cell fueled with hydrogen at 1073 K. However, the power density of the DME cell decreased dramatically with decreasing temperature and showed lower maximum power density than H2 cell at 973 K due to high anodic overpotential. The oxidation of DME on Ni was rather complex, and there were at least two arcs in the impedance spectra under polarization, while there was only one arc when the anode was exposed to H2. The activity of the anode was improved greatly by using Ni-Sm3+ doped ceria (Ni-SDC) composite anode or Ni-SDC/SDC bilayer anode. DME decomposition into CH4, CO, and H2 takes place at the first step, and the overall reaction is close to the partial oxidation of DME into CO and H2 with increasing current density. © 2002 The Electrochemical Society. All rights reserved.