Performance of a solid oxide fuel cell utilizing hydrogen sulfide as fuel

The electrochemical performance of a hydrogen sulfide solid oxide fuel cell having the configuration H2S Pt/(ZrO2)(0.92)(Y2O3)(0.08)/Pt, air has been examined at atmospheric pressure and 750-800 degreesC using both pure and 5% H2S anode feed streams. The performance of the cell is higher when using diluted H2S feed compared with pure H2S feed: current densities up to 100 mA cm(-2) and power densities up to 15.4 mW cm(-2) have been achieved using diluted H2S gas (5%) at 800 degreesC. However, the platinum anode degrades over time in H2S stream due to the formation of PtS. Electrochemical oxidation of H2S on the Pt anode significantly accelerated its degradation. Polarization and impedance spectroscopy measurements show that at low current density (i) electrochemical reaction is the major cause of polarization in the fuel cell. Ohmic loss due to the resistance of the electrolyte material and the electrical connecting wire is a major part of cell polarization at high i. (C) 2001 Elsevier Science B.V. All rights reserved.